Dr Jonny Lees
Pennaeth Adran, Peirianneg Drydanol ac Electronig
Darllenydd
- Ar gael fel goruchwyliwr ôl-raddedig
Trosolwyg
Jonathan Lees became a chartered Engineer in 1999 and obtained MSc. and PhD. degrees from Cardiff University in 2002 and 2006 respectively. He is currently employed as a Lecturer in Non-Linear Microwave Characterisation within Cardiff University’s centre for High Frequency Engineering where his key research areas are linear-efficient PA design and characterisation with a specific interest in the design and optimisation of High-Efficiency Power Amplifiers. His work in this area culminated in the first published GaN Doherty amplifier, and his more recent activities consider the development of novel high-power, broad-band time-domain measurement and load-pull techniques that directly address the current and future needs of modern communication systems. Development of non-linear time-domain and load-pull microwave measurement systems. Current research activities include investigation into RF properties of materials, microwave heating and novel applications of microwave engineering.Electrical & Electronic Engineering
Health, Technology and the Digital World
Dr. Lees is currently the course Tutor for the MSc. in Wireless and Microwave Communications Engineering.
Cyhoeddiad
2024
- Sadeque, M. G. et al. 2024. 3.3–4.3 GHz efficient continuous class-F gallium nitride power amplifier based on simplified real frequency technique and harmonic tuning. PLoS ONE 19(8), article number: e0306738. (10.1371/journal.pone.0306738)
- Bogusz, A., Li, W., Lees, J., Quaglia, R., Montoro, G., Gilabert, P. L. and Cripps, S. 2024. Design and characterization of an MMIC current mode outphasing power amplifier. Presented at: IEEE/MTT-S International Microwave Symposium, Washington, DC, USA, 16-21 June 2024Proceedings of IEEE/MTT-S International Microwave Symposium. IEEE pp. 580-583., (10.1109/IMS40175.2024.10600335)
- Joshi, L. T., Brousseau, E., Morris, T., Lees, J., Porch, A. and Baillie, L. 2024. Rapid, point-of-care microwave lysis and electrochemical detection of Clostridioides difficile directly from stool samples. Bioengineering 11(6), article number: 632. (10.3390/bioengineering11060632)
2023
- Li, W., Bogusz, A., Lees, J., Quaglia, R., Cripps, S., Montoro, G. and Gilabert, P. L. 2023. Performance modeling and shaping function extraction for dual-input load modulated power amplifiers. Presented at: 2023 IEEE/MTT-S International Microwave Symposium - IMS 2023, San Diego, USA, 11-16 June 2023Proceedings of the 2023 IEEE/MTT-S International Microwave Symposium (IMS). IEEE pp. 203-206., (10.1109/IMS37964.2023.10188039)
- Twigg, J. A., Smith, A., Haury, C., Wilson, M., Lees, J., Waters, M. and Williams, D. W. 2023. Compositional shifts within the denture-associated bacteriome in pneumonia – an analytical cross-sectional study. Journal of Medical Microbiology 72(6) (10.1099/jmm.0.001702)
2022
- Sadeque, M. G., Yusoff, Z., Hashim, S. J., Marzuki, A. S. M., Lees, J. and FitzPatrick, D. 2022. Design of wideband continuous class-f power amplifier using low pass matching technique and harmonic tuning network. IEEE Access 10, pp. 92571-92582. (10.1109/ACCESS.2022.3202886)
2021
- Prior-Jones, M. et al. 2021. Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice. Journal of Glaciology 67(264), pp. 627-640. (10.1017/jog.2021.16)
2020
- Chen, P., Quaglia, R., Lees, J., Merrick, B. M., Alt, A. and Tasker, P. J. 2020. Look-up table method for optimising coupling ratio in broadband sequential power amplifiers. IET Microwaves Antennas and Propagation 14(13), pp. 1626-1634. (10.1049/iet-map.2019.1102)
- Chen, P., Quaglia, R., Lees, J., Merrick, B. M., Alt, A. and Tasker, P. 2020. Efficiency enhancement of a broadband sequential power amplifier using envelope tracking. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160332)
- Chen, P. et al. 2020. Optimising linearity of envelope tracking power amplifier using baseband linearisation approach. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160347)
- Alt, A., Villarruel-Parra, A., Chen, P., Alsahali, S., Forsyth, A., Tasker, P. J. and Lees, J. 2020. Characterising the baseband impedance of supply modulators using simple modulated signals. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160186)
- Chen, P., Alsahali, S., Alt, A., Wang, G., Casbon, M. A., Lees, J. and Tasker, P. J. 2020. Flexible bandwidth reduction technique for envelope tracking using low-pass finite impulse response filters. Electronics Letters 56(12), pp. 586-589. (10.1049/el.2020.0194)
- Ahortor, E. K., Malyshev, D., Williams, C. F., Choi, H., Lees, J., Porch, A. and Baillie, L. 2020. The biological effect of 2.45 GHz microwaves on the viability and permeability of bacterial and yeast cells. Journal of Applied Physics 127(204902), pp. IMPORTED. (10.1063/1.5145009)
- Prior-Jones, M. et al. 2020. Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice. Presented at: EGU General Assembly 2020, Online, 4-8 May 2020. Copernicus {GmbH}, (10.5194/egusphere-egu2020-10204)
- Alsahali, S. et al. 2020. Modulated rapid load pull system for the emulation of envelope tracking power amplifiers. Electronics Letters 56(7), pp. 325-328. (10.1049/el.2019.3896)
- Eblabla, A., Alathbah, M., Wu, Z., Lees, J. and Elgaid, K. 2020. Membrane supported GaN CPW structures for high-frequency and high-power applications. Presented at: 2019 IEEE Asia-Pacific Microwave Conference (APMC), Marina Bay Sands, Singapore, 10-13 December 20192019 IEEE Asia-Pacific Microwave Conference (APMC). IEEE pp. 1179-1181., (10.1109/APMC46564.2019.9038731)
2019
- Alsahali, S., Alt, A., Chen, P., Wang, G., Tasker, P. and Lees, J. 2019. Supply modulator ripple in envelope tracking systems - effects and countermeasures. Presented at: 49th European Microwave Conference (EuMC 2019), Paris, France, 01-03 October 20192019 49th European Microwave Conference (EuMC). IEEE pp. 710-713., (10.23919/EuMC.2019.8910890)
- Chaudhary, M. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. 2019. Auxiliary envelope tracking focused investigations of a 10W GaN HEMTs device. Presented at: 3rd International Conference on Circuits, Systems and Devices (ICCSD), Chengdu, China, 23-25 Aug 2017Proceedings of 3rd International Conference on Circuits, Systems and Devices (ICCSD). IEEE pp. 92., (10.1109/ICCSD.2019.8843202)
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. and Cripps, S. 2019. Wideband compact planar balun for applications in outphasing and push-pull amplifiers. Electronics Letters 55(16), pp. 912-914. (10.1049/el.2018.7915)
- Mokhti, Z. A., Lees, J., Cassan, C., Alt, A. and Tasker, P. J. 2019. The nonlinear drain-source capacitance effect on continuous-mode class-B/J power amplifiers. IEEE Transactions on Microwave Theory and Techniques 67(7), pp. 2741-2747. (10.1109/TMTT.2019.2918309)
- Hamzah, H., Ahortor, E., Malyshev, D., Choi, H., Lees, J., Baillie, L. and Porch, A. 2019. A compact microwave applicator for the rapid detection of clostridium difficile. Presented at: 2019 IEEE MTT-S International Microwave Biomedical Conference (IMBioC), Nanjing, China, 6-8 May 20192019 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). IEEE, (10.1109/IMBIOC.2019.8777882)
- Alt, A. et al. 2019. Analysis of gain variation with changing supply voltages in GaN HEMTs for envelope tracking power amplifiers. IEEE Transactions on Microwave Theory and Techniques 67(7), pp. 2495-2504. (10.1109/TMTT.2019.2916404)
- Alsahali, S. et al. 2019. A novel modulated rapid load pull system with digital pre-distortion capabilities. Presented at: 2019 93rd ARFTG Microwave Measurement Conference (ARFTG), Boston, MA, USA, 7 June 2019. , (10.1109/ARFTG.2019.8739220)
- Eblabla, A., Li, X., Alathbah, M., Wu, Z., Lees, J. and Elgaid, K. 2019. Multi-channel AlGaN/GaN lateral schottky barrier diodes on low-resistivity silicon for sub-THz integrated circuits applications. IEEE Electron Device Letters 40(6), pp. 878-880. (10.1109/LED.2019.2912910)
- Williams, C. F. et al. 2019. Bioluminescence of Vibrio fischeri: bacteria respond quickly and sensitively to pulsed microwave electric (but not magnetic) fields. Journal of Biomedical Optics 24(5), article number: 51412. (10.1117/1.JBO.24.5.051412)
- Alt, A., Chen, P., Alsahali, S., Wang, G., Quaglia, R., Tasker, P. and Lees, J. 2019. Impact of the input impedance on the linearity of supply modulated GaN HEMT power amplifiers. Presented at: European Microwave Week 2019 (EuMW2019), 29 September - 03 October 2019.
- Malyshev, D., Williams, C. F., Lees, J., Baillie, L. and Porch, A. 2019. Model of microwave effects on bacterial spores. Journal of Applied Physics 125(12), article number: 124701. (10.1063/1.5085442)
- Alt, A., Quaglia, R., Chen, P., Alsahali, S., Tasker, P. and Lees, J. 2019. Class B* - A new high efficiency RF DC/DC converter concept using second harmonic generation/injection. Presented at: WPTC 2018: IEEE MTT-S Wireless Power Transfer Conference, Montreal, Quebec, 3-7 June 20182018 IEEE Wireless Power Transfer Conference (WPTC). IEEE, (10.1109/WPT.2018.8639317)
- Quaglia, R. and Lees, J. 2019. Simplified analysis of the effect of load variation in common Doherty power amplifier architectures. Presented at: 2019 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR), Orlando, FL, USA, 20-23 Jan 2019IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR). IEEE
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. T. and Cripps, S. 2019. Design and characterisation of an outphasing power amplifier with balun combiner. Presented at: 2019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G), Altanta, GA, USA, 15-16 August 20192019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G). IEEE pp. 1-3., (10.1109/IMC-5G47857.2019.9160351)
2018
- Alt, A., Quaglia, R., Chen, P., Alsahali, S., Tasker, P. J. and Lees, J. 2018. Analysis of highly efficient self-synchronous class-F microwave rectifiers using waveform engineering. Presented at: 48th European Microwave Conference (EuMC), Madrid, Spain, 23-27 Sep 2018Proceedings of the 48th European Microwave Conference. Piscataway, NJ: IEEE pp. 773-776., (10.23919/EuMC.2018.8541564)
- Alt, A., Chen, P., Alsahali, S., Quaglia, R., Tasker, P. and Lees, J. 2018. Comparing FET technologies in terms of their suitability for broadband envelope tracking power amplifiers. Presented at: InMMIC, Brive La Gaillarde, 5-6 July 2018. pp. -.
- Chen, P., Alsahali, S., Alt, A., Lees, J. and Tasker, P. J. 2018. Behavioral modeling of GaN power amplifiers using long short-term memory networks. Presented at: International Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC), Brive La Gaillarde, France, 5-6 Jul 2018International Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC). IEEE, (10.1109/INMMIC.2018.8429984)
- Williams, C. et al. 2018. Real-time microscopic observation of biological interactions with microwave fields. Presented at: International Microwave Biomedical Conference (IMBioC), Philadelphia, USA, 14-15 Jun 2018International Microwave Biomedical Conference (IMBioC). IEEE pp. 199., (10.1109/IMBIOC.2018.8428902)
- Chaudhary, M. A., Memon, Z. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. 2018. Optimization of out-of-band impedance environment for linearity improvements of microwave power transistors. Presented at: 2018 5th International Conference on Electrical and Electronic Engineering (ICEEE), Istanbul, Turkey, 3-5 May 20182018 5th International Conference on Electrical and Electronic Engineering (ICEEE). IEEE pp. 219-223., (10.1109/ICEEE2.2018.8391334)
- Hamzah, H., Lees, J. and Porch, A. 2018. Split ring resonator with optimised sensitivity for microfluidic sensing. Sensors and Actuators A: Physical 276, pp. 1-10. (10.1016/j.sna.2018.03.023)
- Hamzah, H., Abduljabar, A., Lees, J. and Porch, A. 2018. A compact microwave microfluidic sensor using a re-entrant cavity. Sensors 18(3), article number: 910. (10.3390/s18030910)
- Chaudhary, M. A., Memon, Z. A., Lees, J., Benedikt, J. and Tasker, P. 2018. Multitone measurement system for linearity investigations of microwave devices. Presented at: International Multi-Topic Conference (Inmic), Lahore, Pakistan, 24-26 Nov 2017International Multi-Topic Conference (Inmic). IEEE, (10.1109/INMIC.2017.8289455)
- Bogusz, A., Costello, Z., Quaglia, R., Bell, J., Lees, J., Tasker, P. and Cripps, S. 2018. Power and efficiency continuous modes in saturated GaN HEMT devices. Presented at: Inmmic 2018, Brive-La-Gaillarde, France, 5- 6 July 2018.
2017
- Alt, A. and Lees, J. 2017. Improving efficiency, linearity and linearisability of an asymmetric doherty power amplifier by modulating the peaking amplifier’s supply voltage. Presented at: 20th EuMW 2017, Nuremberg, Germany, 8-13 October 20172017 47th European Microwave Conference (EuMC). IEEE pp. 464-467., (10.23919/EuMC.2017.8230890)
- Hefford, S., Parker, N., Lees, J. and Porch, A. 2017. Monitoring changes in microwave asorption of Ti64 powder during microwave sintering. Presented at: 2017 47th European Microwave Conference (EuMC), Nuremberg, Germany, 10-12 October 20172017 47th European Microwave Conference (EuMC). IEEE pp. 927-929., (10.23919/EuMC.2017.8230997)
- Zhou, H., Pal, A., Mehta, A., Nagasundaram, E., Lees, J. and Mirshekar-Syahkal, D. 2017. Power amplifier and antenna integration utilizing capacitively coupled feeding mechanism. Presented at: International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, San Diego, CA, USA, 9-14 July 20172017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE pp. 2355-2356., (10.1109/APUSNCURSINRSM.2017.8073220)
- Abduljabar, A. A., Clark, N., Lees, J. and Porch, A. 2017. Dual mode microwave microfluidic sensor for temperature variant liquid characterization. IEEE Transactions on Microwave Theory and Techniques 65(7), pp. 2572 - 2582. (10.1109/TMTT.2016.2647249)
- Pal, A., Zhou, H., Mehta, A., Nagasundaram, E., Lees, J. and Mirshekar-Syahkal, D. 2017. Co-design of an antenna-power amplifier RF front-end block without matching network for 2.4 GHz WiFi application. Presented at: 2017 IEEE Radio and Wireless Symposium (RWS), Phoenix, AZ, USA, 15-18 January 20172017 IEEE Radio and Wireless Symposium (RWS). IEEE pp. 201-203., (10.1109/RWS.2017.7885987)
- Dong, S., Lees, J. and Tasker, P. J. 2017. A de-embedding network at higher frequency and its error analysis. Presented at: IEEE International Conference on Electronic Information and Communication Technology (ICEICT), Harbin, China, 20-22 Aug 2016IEEE International Conference on Electronic Information and Communication Technology (ICEICT). IEEE pp. 512-514., (10.1109/ICEICT.2016.7879754)
- Chaudhary, M. A., Memon, Z. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. J. 2017. Characterization of baseband electrical memory in microwave devices using multi-tone measurement system. Presented at: 2016 16th Mediterranean Microwave Symposium (MMS), 14-16 November 201616th Mediterranean Microwave Symposium (MMS), 2016. IEEE pp. 1., (10.1109/MMS.2016.7803811)
2016
- Dong, S., Tasker, P. J., Wang, G. and Lees, J. 2016. A practicable de-embedding network at higher frequency of a packaged GaN device. Presented at: 2016 IEEE MTT-S International Wireless Symposium (IWS), 14-16 March 2016IEEE MTT-S International Wireless Symposium (IWS), 2016. IEEE pp. 1., (10.1109/IEEE-IWS.2016.7585473)
- Yusoff, Z., Annuar, F. M., Kung, F., Hashim, S. J., Lees, J. and Cripps, S. C. 2016. The effect of tracking generator efficiency to overall RF power amplifier system efficiency. Presented at: 2016 IEEE International Conference on Semiconductor Electronics (ICSE), 17-19 August 20162016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE pp. 344-347., (10.1109/SMELEC.2016.7573662)
- Williams, C. F. et al. 2016. What the deep sea can tell us about microwaves. Presented at: International Microwave Symposium IMS, San Francisco, California, 22-27 May 2016Microwave Symposium (IMS), 2016 IEEE MTT-S International. IEEE, (10.1109/MWSYM.2016.7540432)
- Williams, C. F., Geroni, G. M., Pirog, A., Lloyd, D., Lees, J. and Porch, A. 2016. The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation. Applied Physics Letters 109(9), article number: 93701. (10.1063/1.4961970)
- Chaudhary, M. A., Lees, J., Benedikt, J. and Tasker, P. J. 2016. Modulated waveform measurement and engineering system. Presented at: 2015 2nd International Conference on Electronics and Communication Systems (ICECS), Cairo, Egypt, 6-9 December 20152015 IEEE International Conference on Electronics, Circuits, and Systems (ICECS 2015). Institute of Electrical and Electronics Engineers (IEEE) pp. 252-255., (10.1109/ICECS.2015.7440296)
- Yusoff, Z., Lees, J., Chaudhary, M. A. and Cripps, S. C. 2016. Ferrite toroidal core with a trifilar wound RF broadband transformer design for tracking generators in wideband code division multiple access envelope tracking RFPA systems. Journal of Electromagnetic Waves and Applications 30(5), pp. 599-611. (10.1080/09205071.2016.1138899)
2015
- Imtiaz, A., Lees, J., Choi, H. and Joshi, L. T. 2015. An integrated continuous class-F-1 mode power amplifier design approach for microwave enhanced portable diagnostic applications. IEEE Transactions on Microwave Theory and Techniques 63(10), pp. 3007-3015. (10.1109/TMTT.2015.2472417)
- Brazzini, T. et al. 2015. Study of hot electrons in AlGaN/GaN HEMTs under RF Class B and Class J operation using electroluminescence. Microelectronics Reliability 55(12), pp. 2493-2498. (10.1016/j.microrel.2015.09.023)
- Mokhti, Z. A., Lees, J., Tasker, P. J. and Cassan, C. 2015. Investigating the linearity versus efficiency trade-off of different power amplifier modes in an envelope tracking architecture. 2015 10th European microwave integrated circuits conference (eumic), pp. 357-360. (10.1109/EuMIC.2015.7345143)
- Brazzini, T. et al. 2015. Electroluminescence of hot electrons in AlGaN/GaN high-electron-mobility transistors under radio frequency operation. Applied Physics Letters 106(21), article number: 213502. (10.1063/1.4921848)
- Imtiaz, A., Hartley, J., Choi, H. and Lees, J. 2015. A high power high efficiency integrated solid-state microwave heating structure for portable diagnostic healthcare applications. Presented at: IEEE MTT-S 2014 IEEE International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications, London, 8-10 December 20142014 IEEE MTT-S international microwave workshop series on RF and wireless technologies for biomedical and healthcare applications (IMWS-Bio). IEEE pp. 1-3., (10.1109/IMWS-BIO.2014.7032437)
2014
- Hartley, J., Lees, J., Cuenca, J. and Choi, H. 2014. Assessment of machine oil quality by microwave cavity perturbation method. Presented at: 2014 International Symposium on Information Technology Convergence (ISITC 2014), Jeonju, Republic of Korea, 30-31 October 2014.
- Koh, M., Bell, J. J., Williams, D., Patterson, A., Lees, J., Root, D. E. and Tasker, P. J. 2014. Frequency scalable large signal transistor behavioral model based on admittance domain formulation. Presented at: International Microwave Symposium, Tampa, Florida, 1-6 June 20142014 IEEE MTT-S International Microwave Symposium (IMS). Picastaway, NJ: IEEE pp. 1-3., (10.1109/MWSYM.2014.6848287)
- A Mokhti, Z. B., Tasker, P. J. and Lees, J. 2014. Correlation analysis between a VNA-based passive load pull system and an oscilloscope-based active load pull system: a case study. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 6 June 201483rd ARFTG Microwave Measurement Conference (ARFTG), 2014. pp. 1-4., (10.1109/ARFTG.2014.6899535)
- Ogboi, F. L. et al. 2014. Investigation of various envelope complexity linearity under modulated stimulus using a new envelope formulation approach. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 1 - 6 June 2014Compound Semiconductor Integrated Circuit Symposium (CSICs), 2014 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2014.6978563)
- Yang, F., Lees, J., Choi, H., Yu, H. and Tasker, P. J. 2014. Continuous class BJ power amplifier with DGS output matching. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 6 June 2014Microwave Symposium (IMS), 2014 IEEE MTT-S International. IEEE pp. 1-4., (10.1109/MWSYM.2014.6848562)
- A Mokhti, Z. B., Tasker, P. J. and Lees, J. 2014. Using waveform engineering to optimize class-F power amplifier performance in an envelope tracking architecture. Presented at: 44th European Microwave Conference (EuMC) 2014, Rome, Italy, 6-9 October 201444th European Microwave Conference (EuMC 2014). IEEE pp. 1301-1304., (10.1109/EuMC.2014.6986682)
- Aldoumani, A., Williams, T., Lees, J. and Tasker, P. J. 2014. Enhanced vector calibration of load-pull measurement systems. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, FL, USA, 6 June 2014ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE pp. 1-4., (10.1109/ARFTG.2014.6899508)
- Ogboi, F. L. et al. 2014. High bandwidth investigations of a baseband linearization approach formulated in the envelope domain under modulated stimulus. Presented at: European Microwave Conference (EuMC) 2014, Rome, Italy, 6-9 October 2014European Microwave Conference (EuMC), Vol. 44. IEEE pp. 1305-1308., (10.1109/EuMC.2014.6986683)
- Mokhti, Z. A., Tasker, P. J. and Lees, J. 2014. Using waveform engineering to optimize Class-F power amplifier performance in an envelope tracking architecture. Presented at: 9th European Microwave Integrated Circuit Conference (EuMIC), Rome, Italy, 6-7 Octpber 2014European Microwave Integrated Circuit Conference (EuMIC), 2014 9th. IEEE pp. 357-360., (10.1109/EuMIC.2014.6997866)
- Mokhti, Z. A., Tasker, P. J. and Lees, J. 2014. Analyzing the improvement in efficiency through the integration of class-F power amplifiers compared to class-AB in an envelope tracking architecture. Presented at: 26th International Teletraffic Congress (ITC), Karlskrona, Sweden, 9-11 September 2014Teletraffic Congress (ITC), 2014 26th International. pp. 1-4., (10.1109/ITC.2014.6932967)
- Ogboi, F. L. et al. 2014. Sensitivity of AM/AM linearizer to AM/PM distortion in devices. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, FL, USA, 6 June 2014ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE pp. 1-4., (10.1109/ARFTG.2014.6899507)
2013
- Kural, A., Pullin, R., Holford, K. M., Lees, J., Naylon, A. J., Paget, C. and Featherston, C. A. 2013. Design and characterization of an ultrasonic lamb-wave power delivery system. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 60(6), pp. 1134-1140. (10.1109/TUFFC.2013.2676)
- Morgan, A. J. et al. 2013. Efficient microwave heating of microfluidic systems. Sensors and Actuators B: Chemical 181, pp. 904-909. (10.1016/j.snb.2013.02.099)
- Schmid, U. et al. 2013. Hybrid energy storage system for wireless sensor node powered by aircraft specific thermoelectric energy harvesting. Presented at: Smart Sensors, Actuators, and MEMS VI, Grenoble, France, 24 April 2013Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI, Vol. 8763. SPIE pp. 876307., (10.1117/12.2017691)
- Featherston, C., Holford, K. M., Pullin, R., Lees, J., Eaton, M. J. and Pearson, M. R. 2013. An autonomous structural health monitoring solution. Presented at: Microtechnologies 2013, Grenoble, France, 24-26 April 2013Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI. Society of Photo-Optical Instrumentation Engineers (SPIE) pp. 876302., (10.1117/12.2018401)
- Yusoff, Z., Lees, J., Chaudhary, M. A., Carrubba, V., Choi, H., Tasker, P. J. and Cripps, S. C. 2013. Simple and low-cost tracking generator design in envelope tracking radio frequency power amplifier system for WCDMA applications. IET Microwaves, Antennas & Propagation 7(10), pp. 802-808. (10.1049/iet-map.2013.0091)
- Thangaraj, K., Elefsiniots, A., Becker, T., Schmid, U., Lees, J., Featherston, C. A. and Pullin, R. 2013. Energy storage options for wireless sensors powered by aircraft specific thermoelectric energy harvester. Microsystem Technologies 20(4-5), pp. 701-707. (10.1007/s00542-013-2009-3)
- Koh, M., Bell, J. J., Williams, D., Patterson, A., Wohlmuth, W., Lees, J. and Tasker, P. J. 2013. X-band MMIC scalable large signal model based on unit cell behavioral data model and passive embedding network. Presented at: International Microwave Symposium, Seattle, WA, 2-7 June 20132013 IEEE MTT-S International Microwave Symposium Digest (IMS). Picastaway, NJ: IEEE pp. 1-4., (10.1109/MWSYM.2013.6697424)
- Aldoumani, A., Tasker, P. J., Saini, R. S., Bell, J. J., Williams, T. and Lees, J. 2013. Operation and calibration of VNA-based large signal RF I-V waveform measurements system without using a harmonic phase reference standard. Presented at: ARFTG Microwave Measurement Conference (ARFTG), Seattle, WA, 7-7 June 20132013 81st ARFTG Microwave Measurement Conference (ARFTG). Picastaway, NJ: IEEE pp. 1-4., (10.1109/ARFTG.2013.6579055)
- Ogboi, F. L. et al. 2013. A LSNA configured to perform baseband engineering for device linearity investigations under modulated excitations. Presented at: 43rd European Microwave Conference, Nuremberg, Germany, 7-10 October 2013Proceedings of the 43rd European Microwave Conference. pp. 684-687.
- Chaudhary, M. A., Memon, Z. A., Lees, J., Benedikt, J. and Tasker, P. J. 2013. Investigation of baseband electrical memory effects on the dynamic characteristics of power transistors. Presented at: 2013 16th International Multi Topic Conference (INMIC), Lahore, Pakistan, 19-20 December 2013Multi Topic Conference (INMIC), 2013 16th International. IEEE pp. 106-109., (10.1109/INMIC.2013.6731333)
- Chaudhary, M. A., Lees, J., Benedikt, J. and Tasker, P. J. 2013. Reduction of baseband electrical memory effects using broadband active baseband load-pull. Presented at: 2013 IEEE International Wireless Symposium (IWS), Beijing, China, 14-18 April 2013Wireless Symposium (IWS), 2013 IEEE International. IEEE pp. 1-4., (10.1109/IEEE-IWS.2013.6616709)
- Hone, T. M. et al. 2013. Inverse active load-pull in an inverse Doherty amplifier. Presented at: 2013 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications, Santa Clara, CA, USA, 20 Jauary 2013Power Amplifiers for Wireless and Radio Applications (PAWR), 2013 IEEE Topical Conference on. IEEE pp. 4-6., (10.1109/PAWR.2013.6490170)
- Pearson, M., Lees, J., Featherston, C. and Pullin, R. 2013. 9th international conference on advances in experimental mechanics. Presented at: 9th International Conference on Advances in Experimental Mechanics, Cardiff, Wales, 3 - 5 September 2013.
2012
- Bensmida, S. et al. 2012. Nonlinear envelope tracking for efficiency optimization of power amplifiers. Presented at: 7th European Microwave Integrated Circuits Conference (EuMIC) 2012, Amsterdam, The Netherlands, 29-30 October 20127th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE pp. 480-483.
- Carrubba, V., Akmal, M., Quay, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2012. The Continuous Inverse Class-F Mode With Resistive Second-Harmonic Impedance. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1928-1936. (10.1109/TMTT.2012.2189228)
- Hone, T. M. et al. 2012. Controlling Active Load-Pull in a Dual-Input Inverse Load Modulated Doherty Architecture. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1797-1804. (10.1109/TMTT.2012.2190748)
- McGenn, W., Choi, H., Lees, J., Uren, M. J., Benedikt, J. and Tasker, P. J. 2012. Development of a RF waveform stress test procedure for GaN HFETs subjected to infinite VSWR sweeps. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259725)
- Carrubba, V. et al. 2012. Continuous-ClassF3 power amplifier mode varying simultaneously first 3 harmonic impedances. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6258343)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A 40W push-pull power amplifier for high efficiency, decade bandwidth applications at microwave frequencies. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest (MTT, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259418)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A Novel Formulation for High Efficiency Modes in Push-Pull Power Amplifiers Using Transmission Line Baluns. IEEE Microwave and Wireless Components Letters 22(5), pp. 257-259. (10.1109/LMWC.2012.2191273)
- Pullin, R. et al. 2012. On the Development of a Damage Detection System using Macro-fibre Composite Sensors. Journal of Physics. Conference Series 382(1), article number: 12049. (10.1088/1742-6596/382/1/012049)
- Tasker, P. J., Carrubba, V., Wright, P., Lees, J., Benedikt, J. and Cripps, S. C. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS), La Jolla, CA, USA, 14-17 October 2012Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2012.6340048)
- Mimis, K., Morris, K. A., Beach, M. A., McGeehan, J. P., Lees, J., Benedikt, J. and Tasker, P. J. 2012. Overlapped segment piece-wise polynomial pre-distortion for the linearisation of power amplifiers in the presence of high PAPR OFDM signals. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. pp. 1-3., (10.1109/MWSYM.2012.6259543)
- Akmal, M., Carrubba, V., Lees, J., Benedikt, J. and Tasker, P. J. 2012. An enhanced modulated waveform measurement system. Australian Journal of Electrical and Electronics Engineering 9(4), pp. 429-438. (10.7158/E11-033.2012.9.4)
- Arnold, M., Featherston, C. A., Pearson, M. R., Lees, J. and Kural, A. 2012. Energy management systems for energy harvesting in structural health monitoring applications. Key Engineering Materials 518, pp. 137-153. (10.4028/www.scientific.net/KEM.518.137)
- Akmal, M. et al. 2012. Characterization of electrical memory effects for complex multi-tone excitations using broadband active baseband load-pull. Presented at: 7th European Microwave Integrated Circuits Conference, Amsterdam, The Netherlands, 29-30 October 20127th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE pp. 885-888.
2011
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. On the extension of the continuous class-F mode power amplifier. IEEE Transactions on Microwave Theory and Techniques 59(5), pp. 1294-1303. (10.1109/TMTT.2011.2117435)
- Yusoff, Z. B., Akmal, M., Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. The benefit of GaN characteristics over LDMOS for linearity improvement using drain modulation in power amplifier system. Presented at: 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, Vienna, Austria, 18-19 April 20112011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE pp. 109-112., (10.1109/INMMIC.2011.5773334)
- Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. A novel highly efficient broadband continuous class-F RFPA delivering 74% average efficiency for an octave bandwidth. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 20112011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 350-353., (10.1109/MWSYM.2011.5972701)
- Yusoff, Z. B., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. Linearity improvement in RF power amplifier system using integrated Auxiliary Envelope Tracking system. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1752-1755., (10.1109/MWSYM.2011.5972769)
- FitzPatrick, D., Saini, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. A waveform engineering approach to the design of improved efficiency wideband MMIC amplifiers. Presented at: Wireless and Microwave Technology Conference (WAMICON), 2011 IEEE 12th Annual., Clearwater Beach, FL, USA, 18-19 April 20112011 IEEE 12th Annual Wireless and Microwave Technology Conference (WAMICON), Clearwater Beach, FL, 18-19 April 2011. Los Alamitos, CA: IEEE pp. 225-230., (10.1109/WAMICON.2011.5872859)
- Akmal, M. et al. 2011. Linearity enhancement of GaN HEMTs under complex modulated excitation by optimizing the baseband impedance environment. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1747-1750., (10.1109/MWSYM.2011.5972833)
- Smith, R. M., Cripps, S. C., Tasker, P. J., Benedikt, J. and Lees, J. 2011. A design methodology for the realization of multi-decade baluns at microwave frequencies. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1204-1208., (10.1109/MWSYM.2011.5972702)
- Bell, J. J., Saini, R., Woodington, S. P., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Behavioral model analysis using simultaneous active fundamental load-pull and harmonic source-pull measurements at X-band. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International. New York: IEEE pp. 982-986., (10.1109/MWSYM.2011.5972803)
- Saini, R. et al. 2011. High speed non-linear device characterization and uniformity investigations at X-band frequencies exploiting behavioral models. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034552)
- Carrubba, V. et al. 2011. High-speed device characterization using an active load-pull system and waveform engineering postulator. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034553)
- Canning, T. A. J., Almuhaisen, A., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Utilization of RF I-V waveform load-pull information to identify the role FET knee profile has on locating the efficiency maxima. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183864)
- Saini, R., Bell, J. J., Williams, T., Lees, J., Benedikt, J. and Tasker, P. J. 2011. Interpolation and extrapolation capabilities of non-linear behavioural models. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183865)
- Carrubba, V. et al. 2011. Exploring the Design Space for Broadband PAs using the Novel "Continuous Inverse Class-F Mode". Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 41st European Microwave Conference (EuMC). IEEE pp. 333-336.
- Hone, T. et al. 2011. Optimized load modulation in a doherty amplifier using a current injection technique. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 296-299.
- Akmal, M. et al. 2011. An enhanced modulated waveform measurement system for the robust characterization of microwave devices under modulated excitation. Presented at: Microwave Integrated Circuits Conference (EuMIC), 2011 European, Manchester, 10-11 October 2011Microwave Integrated Circuits Conference (EuMIC), 2011 European. IEEE pp. 180-183.
- Paynter, M. et al. 2011. Non-linear large signal PA modelling for switching-mode operation (class-F/continuous class-F). Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 152-155.
- Almuhaisen, A., Lees, J., Cripps, S. C., Tasker, P. J. and Benedikt, J. 2011. Wide band high-efficiency power amplifier design. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 184-187.
2010
- Hashmi, M. S., Clarke, A. L., Lees, J., Helaoui, M., Tasker, P. J. and Ghannouchi, F. M. 2010. Agile harmonic envelope load-pull system enabling reliable and rapid device characterization. Measurement Science and Technology 21(5), article number: 55109. (10.1088/0957-0233/21/5/055109)
- Hashmi, M. S., Clarke, A. L., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. J. 2010. An accurate calibrate-able multiharmonic active load-pull system based on the envelope load-pull concept. IEEE Transactions on Microwave Theory and Techniques 58(3), pp. 656-664. (10.1109/TMTT.2010.2040403)
- Clarke, A. L., Akmal, M., Lees, J., Tasker, P. J. and Benedikt, J. 2010. Investigation and analysis into device optimization for attaining efficiencies in-excess of 90% when accounting for higher harmonics. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 1114-1117., (10.1109/MWSYM.2010.5517222)
- Akmal, M. et al. 2010. The effect of baseband impedance termination on the linearity of GaN HEMTs. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561636. pp. 1046-1049.
- Akmal, M. et al. 2010. The impact of baseband electrical memory effects on the dynamic transfer characteristics of microwave power transistors. Presented at: 2010 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC), Gothenburg, Sweden. Vol. 548011. pp. 148-151.
- Woodington, S. P., Saini, R., Williams, D., Lees, J., Benedikt, J. and Tasker, P. J. 2010. Behavioral model analysis of active harmonic load-pull measurements. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 2010Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International. New York: IEEE pp. 1688-1691., (10.1109/MWSYM.2010.5517261)
- Almuhaisen, A., Wright, P. T., Lees, J., Tasker, P. J., Cripps, S. C. and Benedikt, J. 2010. Novel wide band high-efficiency active harmonic injection power amplifier concept. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 664-667., (10.1109/MWSYM.2010.5514759)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. 2010. Exploitation of active load-pull and DLUT models in MMIC design. Presented at: IEEE Radio Frequency Integrated Circuits Symposium, Anaheim, CA, USA, 23-25 May 2010Proceedings of the 2010 IEEE Radio Frequency Integrated Circuits Symposium May 23-25, 2010, Anaheim, California, USA. Piscataway, NJ: IEEE pp. 487-490., (10.1109/RFIC.2010.5477406)
- Naylon, A. J. et al. 2010. Efficient Microwave heating and dielectric characterization of microfluidic systems. Presented at: Proceedings of MicroTAS 2010, Groningen, The Netherlands. pp. 2092-2094.
- Bensmida, S. et al. 2010. Generic pre-distortion of a Class-J Power amplifier. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561648. pp. 1022-1025.
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2010. The continuous Class-F Mode mode power amplifier. Presented at: European Microwave Conference (EuMC) 2010, Paris, France. Vol. 561630. pp. 1674-1677.
- Lees, J. et al. 2010. Waveform engineering applied to linear-efficient PA design. Presented at: 2010 IEEE 11th Annual Wireless and Microwave Technology Conference (WAMICON 2010), Melbourne Beach, USA, 12-13 April, 2010. Vol. 546184., (10.1109/WAMICON.2010.5461847)
- Saini, R., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. J. 2010. An intelligence driven active loadpull system. Presented at: 75th ARFTG Microwave Measurement Conference: Measurement of Modulated Signals for Communications, Anaheim, USA. Vol. 549632.
- Akmal, M. et al. 2010. Minimization of baseband electrical memory effects in GaN HEMTs using active IF load-pull. Presented at: Asia-Pacific Microwave Conference (22nd : 2010), Yokahama-shi, Japan, 7-10 December 20102010 Asia-Pacific Microwave Conference proceedings : APMC 2010 : Dec. 7-10, Yokohama, Japan. Tokyo, Japan: Institute of Electronics, Information and Communication Engineers (IEICE) pp. 5-8.
2009
- Wright, P., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2009. A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA. IEEE Transactions on Microwave Theory and Techniques 57(12), pp. 3196-3204. (10.1109/TMTT.2009.2033295)
- Fitzpatrick, D. M., Lees, J., Sheikh, A., Benedikt, J. and Tasker, P. J. 2009. Systematic investigation of the impact of harmonic termination in the efficiency performance of above octave bandwidth microwave amplifiers. Presented at: European Microwave Conference, 2009 (EuMC 2009), Rome, Italy, 29 September - 1 October 2009European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications pp. 1445-1448.
- Cripps, S. C., Tasker, P., Clarke, A. L., Lees, J. and Benedikt, J. 2009. On the continuity of high efficiency modes in linear RF power amplifiers. IEEE Microwave and Wireless Components Letters 19(10), pp. 665-667. (10.1109/LMWC.2009.2029754)
- Sheikh, A., Lees, J., Benedikt, J. and Tasker, P. J. 2009. Utilization of a measurement based CAD tool for enhanced pa design investigations. Presented at: 38th European Microwave Conference, 2008 (EuMC 2008), Amsterdam, The Netherlands, 27-31 October 2008Proceedings of the 38th European Microwave Conference, 2008 (EuMC 2008). Los Alamitos, CA: IEEE pp. 1671-1674., (10.1109/EUMC.2008.4751795)
- Hashmi, M. S., Clarke, A. L., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. 2009. Electronic Multi-Harmonic Load-Pull System for Experimentally Driven Power Amplifier Design Optimization. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, USA. pp. 1549-1552.
- Wright, P. T., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2009. An Efficient, Linear, Broadband Class-J-Mode PA Realised Using RF. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, MA, USA, 7-12 June 2009IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE pp. 653-656., (10.1109/MWSYM.2009.5165781)
- Bensmida, S. et al. 2009. Power amplifier memory-less pre-distortion for 3GPP LTE application. Presented at: European Microwave Conference, 2009 (EuMC 2009), Rome, Italy, 29 September - 1 October 2009European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications pp. 1433-1436.
2008
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. J. 2008. Sensitivity of electrical baseband memory effects to higher-order IF components for high-power LDMOS power amplifiers. Electronics Letters 44(5), pp. 358-359. (10.1049/el:20083348)
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. 2008. Reduction of electrical baseband memory effect in high-power LDMOS devices using optimum termination for IMD3 and IMD5 using active load-pull. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 415-418., (10.1109/MWSYM.2008.4633191)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J. and Tasker, P. 2008. Large signal device characterisation using active load-pull for improved MMIC design. Presented at: IET Seminar on RF and Microwave IC Design, London, UK. IET pp. 1-7.
- Lees, J., Williams, T., Woodington, S., McGovern, P., Cripps, S. C., Benedikt, J. and Tasker, P. 2008. Demystifying Device related Memory Effects using Waveform Engineering and Envelope Domain Analysis. Presented at: 38th European Microwave Conference 2008 (EuMC 2008), Amsterdam, The Netherlands. pp. 753-756., (10.1109/EUMC.2008.471562)
- Williams, T., Mojon, O., Woodington, S. P., Lees, J., Barciela, M. F., Benedikt, J. and Tasker, P. J. 2008. A robust approach for comparison and validation of large signal measurement systems. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 257-260., (10.1109/MWSYM.2008.4633152)
- Woodington, S. P. et al. 2008. A novel measurement based method enabling rapid extraction of a RF waveform look-up table based behavioural model. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 1453-1456., (10.1109/MWSYM.2008.463305)
- Wright, P. T., Lees, J., Tasker, P. J. and Benedikt, J. 2008. GaN power transistors in narrow and wide bandwidth applications. Presented at: IET Seminar on Wideband Receivers and Components, London, UK. pp. 1.
2007
- Alghanim, A., Lees, J., Wiliams, T., Benedikt, J. and Tasker, P. 2007. Investigation of electrical base-band memory effects in high power 20w LDMOS power amplifiers. Presented at: 37th European Microwave Conference, Munich, Germany. pp. 48-51., (10.1109/EUMC.2007.4405122)
- Sheikh, A., Tasker, P. J., Lees, J. and Benedikt, J. 2007. The impact of system impedance on the characterisation of high power devices. Presented at: 37th European Microwave Conference (EuMC), Munich, Germany. pp. 949-952., (10.1109/EUMC.2007.4405315)
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. J. 2007. Using active IF load-pull to investigate electrical base-band induced memory effects in high-power LDMOS transistors. Presented at: Asia-Pacific Microwave Conference (APMC 2007), Bangkok, Thailand. IEEE pp. 1-4., (10.1109/APMC.2007.4554737)
2006
- Mayer, M., Arthaber, H., Magerl, G., Kother, D., Lees, J., Benedikt, J. and Tasker, P. 2006. Advanced load pull systems. Presented at: The Institution of Engineering and Technology Seminar on High Efficiency Power Amplifier Design for Next Generation Wireless Applications, Cambridge, UK. pp. 27-54.
- Aubrey, A. J., Hicks, Y. A., Lees, J. and Chambers, J. A. 2006. Using the bi-modality of speech for convolutive frequency domain blind source separation. Presented at: Proceedings of IMA 7th International Conference on Mathematics in Signal Processing, Cirencester, UK.
- Lees, J., Sheikj, A., Benedikt, J. and Tasker, P. 2006. The Design of a Gallium Nitride Doherty Amplifier using Waveform Measurements and Active Harmonic Load-Pull. Presented at: 2006 International Workshop on Integrated Nonlinear Microwave and Millimeter-Wave Circuits, Aveiro, Portugal. pp. 26-29.
- Lees, J. 2006. Doherty amplifier structures for modern microwave communication systems. PhD Thesis, Cardiff University.
2005
- Aboush, Z., Lees, J., Benedikt, J. and Tasker, P. J. 2005. Active harmonic load-pull system for characterising highly mismatched high power transistors. Presented at: IEEE MTT-S International Microwave Symposium Digest 2005, 2005. , (10.1109/MWSYM.2005.1516920)
- Aboush, Z. et al. 2005. High power active harmonic load-pull system for characterisation of high power 100-Watt transistors. Presented at: 35th European Microwave Conference, Paris, France, Vol. 1. pp. 609-612., (10.1109/EUMC.2005.1608930)
- Lees, J. et al. 2005. Experimental gallium nitride microwave Doherty amplifier. IEEE Electronic Letters 41(23), pp. 1284-1285. (10.1049/el:20053155)
- Lees, J. et al. 2005. A comparison of load-pull measurement results of a 4W Phemt involving five European laboratories. Presented at: European Gallium Arsenide and Other Semiconductor Application Symposium, Paris, France, 3-4 October, 2005Proceedings of the European Gallium Arsenide and Other Semiconductor Application Symposium Paris, France,3-4 October, 2005. IEEE pp. 321-324.
- Lees, J. et al. 2005. Characterisation of an experimental gallium nitride microwave Doherty amplifier. Presented at: 35th European Microwave Conference, Paris, France, 4-6 October 200535th European Microwave Conference: conference proceedings. Horizon House
2004
- Lees, J., Haczewski, J., Benedikt, J. and Tasker, P. 2004. An automated multi-stimulus measurement system for characterising multi-device amplifiers. Presented at: 34th European Microwave Conference, Amsterdam, The Netherlands, Vol. Nov-15. pp. 435-438.
2003
- Lees, J., Goss, M., Benedikt, J. and Tasker, P. 2003. Single-tone optimisation of an adaptive-bias Doherty structure. Presented at: Microwave Symposium Digest, IEEE MTT-S International, Philadelphia, USA, 8-13 June 2003Microwave Symposium Digest, IEEE MTT-S International, Vol. 3. IEEE pp. 2213-2216., (10.1109/MWSYM.2003.1210604)
Articles
- Sadeque, M. G. et al. 2024. 3.3–4.3 GHz efficient continuous class-F gallium nitride power amplifier based on simplified real frequency technique and harmonic tuning. PLoS ONE 19(8), article number: e0306738. (10.1371/journal.pone.0306738)
- Joshi, L. T., Brousseau, E., Morris, T., Lees, J., Porch, A. and Baillie, L. 2024. Rapid, point-of-care microwave lysis and electrochemical detection of Clostridioides difficile directly from stool samples. Bioengineering 11(6), article number: 632. (10.3390/bioengineering11060632)
- Twigg, J. A., Smith, A., Haury, C., Wilson, M., Lees, J., Waters, M. and Williams, D. W. 2023. Compositional shifts within the denture-associated bacteriome in pneumonia – an analytical cross-sectional study. Journal of Medical Microbiology 72(6) (10.1099/jmm.0.001702)
- Sadeque, M. G., Yusoff, Z., Hashim, S. J., Marzuki, A. S. M., Lees, J. and FitzPatrick, D. 2022. Design of wideband continuous class-f power amplifier using low pass matching technique and harmonic tuning network. IEEE Access 10, pp. 92571-92582. (10.1109/ACCESS.2022.3202886)
- Prior-Jones, M. et al. 2021. Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice. Journal of Glaciology 67(264), pp. 627-640. (10.1017/jog.2021.16)
- Chen, P., Quaglia, R., Lees, J., Merrick, B. M., Alt, A. and Tasker, P. J. 2020. Look-up table method for optimising coupling ratio in broadband sequential power amplifiers. IET Microwaves Antennas and Propagation 14(13), pp. 1626-1634. (10.1049/iet-map.2019.1102)
- Chen, P., Alsahali, S., Alt, A., Wang, G., Casbon, M. A., Lees, J. and Tasker, P. J. 2020. Flexible bandwidth reduction technique for envelope tracking using low-pass finite impulse response filters. Electronics Letters 56(12), pp. 586-589. (10.1049/el.2020.0194)
- Ahortor, E. K., Malyshev, D., Williams, C. F., Choi, H., Lees, J., Porch, A. and Baillie, L. 2020. The biological effect of 2.45 GHz microwaves on the viability and permeability of bacterial and yeast cells. Journal of Applied Physics 127(204902), pp. IMPORTED. (10.1063/1.5145009)
- Alsahali, S. et al. 2020. Modulated rapid load pull system for the emulation of envelope tracking power amplifiers. Electronics Letters 56(7), pp. 325-328. (10.1049/el.2019.3896)
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. and Cripps, S. 2019. Wideband compact planar balun for applications in outphasing and push-pull amplifiers. Electronics Letters 55(16), pp. 912-914. (10.1049/el.2018.7915)
- Mokhti, Z. A., Lees, J., Cassan, C., Alt, A. and Tasker, P. J. 2019. The nonlinear drain-source capacitance effect on continuous-mode class-B/J power amplifiers. IEEE Transactions on Microwave Theory and Techniques 67(7), pp. 2741-2747. (10.1109/TMTT.2019.2918309)
- Alt, A. et al. 2019. Analysis of gain variation with changing supply voltages in GaN HEMTs for envelope tracking power amplifiers. IEEE Transactions on Microwave Theory and Techniques 67(7), pp. 2495-2504. (10.1109/TMTT.2019.2916404)
- Eblabla, A., Li, X., Alathbah, M., Wu, Z., Lees, J. and Elgaid, K. 2019. Multi-channel AlGaN/GaN lateral schottky barrier diodes on low-resistivity silicon for sub-THz integrated circuits applications. IEEE Electron Device Letters 40(6), pp. 878-880. (10.1109/LED.2019.2912910)
- Williams, C. F. et al. 2019. Bioluminescence of Vibrio fischeri: bacteria respond quickly and sensitively to pulsed microwave electric (but not magnetic) fields. Journal of Biomedical Optics 24(5), article number: 51412. (10.1117/1.JBO.24.5.051412)
- Malyshev, D., Williams, C. F., Lees, J., Baillie, L. and Porch, A. 2019. Model of microwave effects on bacterial spores. Journal of Applied Physics 125(12), article number: 124701. (10.1063/1.5085442)
- Hamzah, H., Lees, J. and Porch, A. 2018. Split ring resonator with optimised sensitivity for microfluidic sensing. Sensors and Actuators A: Physical 276, pp. 1-10. (10.1016/j.sna.2018.03.023)
- Hamzah, H., Abduljabar, A., Lees, J. and Porch, A. 2018. A compact microwave microfluidic sensor using a re-entrant cavity. Sensors 18(3), article number: 910. (10.3390/s18030910)
- Abduljabar, A. A., Clark, N., Lees, J. and Porch, A. 2017. Dual mode microwave microfluidic sensor for temperature variant liquid characterization. IEEE Transactions on Microwave Theory and Techniques 65(7), pp. 2572 - 2582. (10.1109/TMTT.2016.2647249)
- Williams, C. F., Geroni, G. M., Pirog, A., Lloyd, D., Lees, J. and Porch, A. 2016. The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation. Applied Physics Letters 109(9), article number: 93701. (10.1063/1.4961970)
- Yusoff, Z., Lees, J., Chaudhary, M. A. and Cripps, S. C. 2016. Ferrite toroidal core with a trifilar wound RF broadband transformer design for tracking generators in wideband code division multiple access envelope tracking RFPA systems. Journal of Electromagnetic Waves and Applications 30(5), pp. 599-611. (10.1080/09205071.2016.1138899)
- Imtiaz, A., Lees, J., Choi, H. and Joshi, L. T. 2015. An integrated continuous class-F-1 mode power amplifier design approach for microwave enhanced portable diagnostic applications. IEEE Transactions on Microwave Theory and Techniques 63(10), pp. 3007-3015. (10.1109/TMTT.2015.2472417)
- Brazzini, T. et al. 2015. Study of hot electrons in AlGaN/GaN HEMTs under RF Class B and Class J operation using electroluminescence. Microelectronics Reliability 55(12), pp. 2493-2498. (10.1016/j.microrel.2015.09.023)
- Mokhti, Z. A., Lees, J., Tasker, P. J. and Cassan, C. 2015. Investigating the linearity versus efficiency trade-off of different power amplifier modes in an envelope tracking architecture. 2015 10th European microwave integrated circuits conference (eumic), pp. 357-360. (10.1109/EuMIC.2015.7345143)
- Brazzini, T. et al. 2015. Electroluminescence of hot electrons in AlGaN/GaN high-electron-mobility transistors under radio frequency operation. Applied Physics Letters 106(21), article number: 213502. (10.1063/1.4921848)
- Kural, A., Pullin, R., Holford, K. M., Lees, J., Naylon, A. J., Paget, C. and Featherston, C. A. 2013. Design and characterization of an ultrasonic lamb-wave power delivery system. IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control 60(6), pp. 1134-1140. (10.1109/TUFFC.2013.2676)
- Morgan, A. J. et al. 2013. Efficient microwave heating of microfluidic systems. Sensors and Actuators B: Chemical 181, pp. 904-909. (10.1016/j.snb.2013.02.099)
- Yusoff, Z., Lees, J., Chaudhary, M. A., Carrubba, V., Choi, H., Tasker, P. J. and Cripps, S. C. 2013. Simple and low-cost tracking generator design in envelope tracking radio frequency power amplifier system for WCDMA applications. IET Microwaves, Antennas & Propagation 7(10), pp. 802-808. (10.1049/iet-map.2013.0091)
- Thangaraj, K., Elefsiniots, A., Becker, T., Schmid, U., Lees, J., Featherston, C. A. and Pullin, R. 2013. Energy storage options for wireless sensors powered by aircraft specific thermoelectric energy harvester. Microsystem Technologies 20(4-5), pp. 701-707. (10.1007/s00542-013-2009-3)
- Carrubba, V., Akmal, M., Quay, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2012. The Continuous Inverse Class-F Mode With Resistive Second-Harmonic Impedance. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1928-1936. (10.1109/TMTT.2012.2189228)
- Hone, T. M. et al. 2012. Controlling Active Load-Pull in a Dual-Input Inverse Load Modulated Doherty Architecture. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1797-1804. (10.1109/TMTT.2012.2190748)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A Novel Formulation for High Efficiency Modes in Push-Pull Power Amplifiers Using Transmission Line Baluns. IEEE Microwave and Wireless Components Letters 22(5), pp. 257-259. (10.1109/LMWC.2012.2191273)
- Pullin, R. et al. 2012. On the Development of a Damage Detection System using Macro-fibre Composite Sensors. Journal of Physics. Conference Series 382(1), article number: 12049. (10.1088/1742-6596/382/1/012049)
- Akmal, M., Carrubba, V., Lees, J., Benedikt, J. and Tasker, P. J. 2012. An enhanced modulated waveform measurement system. Australian Journal of Electrical and Electronics Engineering 9(4), pp. 429-438. (10.7158/E11-033.2012.9.4)
- Arnold, M., Featherston, C. A., Pearson, M. R., Lees, J. and Kural, A. 2012. Energy management systems for energy harvesting in structural health monitoring applications. Key Engineering Materials 518, pp. 137-153. (10.4028/www.scientific.net/KEM.518.137)
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. On the extension of the continuous class-F mode power amplifier. IEEE Transactions on Microwave Theory and Techniques 59(5), pp. 1294-1303. (10.1109/TMTT.2011.2117435)
- Hashmi, M. S., Clarke, A. L., Lees, J., Helaoui, M., Tasker, P. J. and Ghannouchi, F. M. 2010. Agile harmonic envelope load-pull system enabling reliable and rapid device characterization. Measurement Science and Technology 21(5), article number: 55109. (10.1088/0957-0233/21/5/055109)
- Hashmi, M. S., Clarke, A. L., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. J. 2010. An accurate calibrate-able multiharmonic active load-pull system based on the envelope load-pull concept. IEEE Transactions on Microwave Theory and Techniques 58(3), pp. 656-664. (10.1109/TMTT.2010.2040403)
- Wright, P., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2009. A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA. IEEE Transactions on Microwave Theory and Techniques 57(12), pp. 3196-3204. (10.1109/TMTT.2009.2033295)
- Cripps, S. C., Tasker, P., Clarke, A. L., Lees, J. and Benedikt, J. 2009. On the continuity of high efficiency modes in linear RF power amplifiers. IEEE Microwave and Wireless Components Letters 19(10), pp. 665-667. (10.1109/LMWC.2009.2029754)
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. J. 2008. Sensitivity of electrical baseband memory effects to higher-order IF components for high-power LDMOS power amplifiers. Electronics Letters 44(5), pp. 358-359. (10.1049/el:20083348)
- Lees, J. et al. 2005. Experimental gallium nitride microwave Doherty amplifier. IEEE Electronic Letters 41(23), pp. 1284-1285. (10.1049/el:20053155)
Conferences
- Bogusz, A., Li, W., Lees, J., Quaglia, R., Montoro, G., Gilabert, P. L. and Cripps, S. 2024. Design and characterization of an MMIC current mode outphasing power amplifier. Presented at: IEEE/MTT-S International Microwave Symposium, Washington, DC, USA, 16-21 June 2024Proceedings of IEEE/MTT-S International Microwave Symposium. IEEE pp. 580-583., (10.1109/IMS40175.2024.10600335)
- Li, W., Bogusz, A., Lees, J., Quaglia, R., Cripps, S., Montoro, G. and Gilabert, P. L. 2023. Performance modeling and shaping function extraction for dual-input load modulated power amplifiers. Presented at: 2023 IEEE/MTT-S International Microwave Symposium - IMS 2023, San Diego, USA, 11-16 June 2023Proceedings of the 2023 IEEE/MTT-S International Microwave Symposium (IMS). IEEE pp. 203-206., (10.1109/IMS37964.2023.10188039)
- Chen, P., Quaglia, R., Lees, J., Merrick, B. M., Alt, A. and Tasker, P. 2020. Efficiency enhancement of a broadband sequential power amplifier using envelope tracking. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160332)
- Chen, P. et al. 2020. Optimising linearity of envelope tracking power amplifier using baseband linearisation approach. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160347)
- Alt, A., Villarruel-Parra, A., Chen, P., Alsahali, S., Forsyth, A., Tasker, P. J. and Lees, J. 2020. Characterising the baseband impedance of supply modulators using simple modulated signals. Presented at: 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC), Cardiff, Wales, 16-17 July 20202020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC46721.2020.9160186)
- Prior-Jones, M. et al. 2020. Cryoegg: development and field trials of a wireless subglacial probe for deep, fast-moving ice. Presented at: EGU General Assembly 2020, Online, 4-8 May 2020. Copernicus {GmbH}, (10.5194/egusphere-egu2020-10204)
- Eblabla, A., Alathbah, M., Wu, Z., Lees, J. and Elgaid, K. 2020. Membrane supported GaN CPW structures for high-frequency and high-power applications. Presented at: 2019 IEEE Asia-Pacific Microwave Conference (APMC), Marina Bay Sands, Singapore, 10-13 December 20192019 IEEE Asia-Pacific Microwave Conference (APMC). IEEE pp. 1179-1181., (10.1109/APMC46564.2019.9038731)
- Alsahali, S., Alt, A., Chen, P., Wang, G., Tasker, P. and Lees, J. 2019. Supply modulator ripple in envelope tracking systems - effects and countermeasures. Presented at: 49th European Microwave Conference (EuMC 2019), Paris, France, 01-03 October 20192019 49th European Microwave Conference (EuMC). IEEE pp. 710-713., (10.23919/EuMC.2019.8910890)
- Chaudhary, M. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. 2019. Auxiliary envelope tracking focused investigations of a 10W GaN HEMTs device. Presented at: 3rd International Conference on Circuits, Systems and Devices (ICCSD), Chengdu, China, 23-25 Aug 2017Proceedings of 3rd International Conference on Circuits, Systems and Devices (ICCSD). IEEE pp. 92., (10.1109/ICCSD.2019.8843202)
- Hamzah, H., Ahortor, E., Malyshev, D., Choi, H., Lees, J., Baillie, L. and Porch, A. 2019. A compact microwave applicator for the rapid detection of clostridium difficile. Presented at: 2019 IEEE MTT-S International Microwave Biomedical Conference (IMBioC), Nanjing, China, 6-8 May 20192019 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). IEEE, (10.1109/IMBIOC.2019.8777882)
- Alsahali, S. et al. 2019. A novel modulated rapid load pull system with digital pre-distortion capabilities. Presented at: 2019 93rd ARFTG Microwave Measurement Conference (ARFTG), Boston, MA, USA, 7 June 2019. , (10.1109/ARFTG.2019.8739220)
- Alt, A., Chen, P., Alsahali, S., Wang, G., Quaglia, R., Tasker, P. and Lees, J. 2019. Impact of the input impedance on the linearity of supply modulated GaN HEMT power amplifiers. Presented at: European Microwave Week 2019 (EuMW2019), 29 September - 03 October 2019.
- Alt, A., Quaglia, R., Chen, P., Alsahali, S., Tasker, P. and Lees, J. 2019. Class B* - A new high efficiency RF DC/DC converter concept using second harmonic generation/injection. Presented at: WPTC 2018: IEEE MTT-S Wireless Power Transfer Conference, Montreal, Quebec, 3-7 June 20182018 IEEE Wireless Power Transfer Conference (WPTC). IEEE, (10.1109/WPT.2018.8639317)
- Quaglia, R. and Lees, J. 2019. Simplified analysis of the effect of load variation in common Doherty power amplifier architectures. Presented at: 2019 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR), Orlando, FL, USA, 20-23 Jan 2019IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR). IEEE
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. T. and Cripps, S. 2019. Design and characterisation of an outphasing power amplifier with balun combiner. Presented at: 2019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G), Altanta, GA, USA, 15-16 August 20192019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G). IEEE pp. 1-3., (10.1109/IMC-5G47857.2019.9160351)
- Alt, A., Quaglia, R., Chen, P., Alsahali, S., Tasker, P. J. and Lees, J. 2018. Analysis of highly efficient self-synchronous class-F microwave rectifiers using waveform engineering. Presented at: 48th European Microwave Conference (EuMC), Madrid, Spain, 23-27 Sep 2018Proceedings of the 48th European Microwave Conference. Piscataway, NJ: IEEE pp. 773-776., (10.23919/EuMC.2018.8541564)
- Alt, A., Chen, P., Alsahali, S., Quaglia, R., Tasker, P. and Lees, J. 2018. Comparing FET technologies in terms of their suitability for broadband envelope tracking power amplifiers. Presented at: InMMIC, Brive La Gaillarde, 5-6 July 2018. pp. -.
- Chen, P., Alsahali, S., Alt, A., Lees, J. and Tasker, P. J. 2018. Behavioral modeling of GaN power amplifiers using long short-term memory networks. Presented at: International Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC), Brive La Gaillarde, France, 5-6 Jul 2018International Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC). IEEE, (10.1109/INMMIC.2018.8429984)
- Williams, C. et al. 2018. Real-time microscopic observation of biological interactions with microwave fields. Presented at: International Microwave Biomedical Conference (IMBioC), Philadelphia, USA, 14-15 Jun 2018International Microwave Biomedical Conference (IMBioC). IEEE pp. 199., (10.1109/IMBIOC.2018.8428902)
- Chaudhary, M. A., Memon, Z. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. 2018. Optimization of out-of-band impedance environment for linearity improvements of microwave power transistors. Presented at: 2018 5th International Conference on Electrical and Electronic Engineering (ICEEE), Istanbul, Turkey, 3-5 May 20182018 5th International Conference on Electrical and Electronic Engineering (ICEEE). IEEE pp. 219-223., (10.1109/ICEEE2.2018.8391334)
- Chaudhary, M. A., Memon, Z. A., Lees, J., Benedikt, J. and Tasker, P. 2018. Multitone measurement system for linearity investigations of microwave devices. Presented at: International Multi-Topic Conference (Inmic), Lahore, Pakistan, 24-26 Nov 2017International Multi-Topic Conference (Inmic). IEEE, (10.1109/INMIC.2017.8289455)
- Bogusz, A., Costello, Z., Quaglia, R., Bell, J., Lees, J., Tasker, P. and Cripps, S. 2018. Power and efficiency continuous modes in saturated GaN HEMT devices. Presented at: Inmmic 2018, Brive-La-Gaillarde, France, 5- 6 July 2018.
- Alt, A. and Lees, J. 2017. Improving efficiency, linearity and linearisability of an asymmetric doherty power amplifier by modulating the peaking amplifier’s supply voltage. Presented at: 20th EuMW 2017, Nuremberg, Germany, 8-13 October 20172017 47th European Microwave Conference (EuMC). IEEE pp. 464-467., (10.23919/EuMC.2017.8230890)
- Hefford, S., Parker, N., Lees, J. and Porch, A. 2017. Monitoring changes in microwave asorption of Ti64 powder during microwave sintering. Presented at: 2017 47th European Microwave Conference (EuMC), Nuremberg, Germany, 10-12 October 20172017 47th European Microwave Conference (EuMC). IEEE pp. 927-929., (10.23919/EuMC.2017.8230997)
- Zhou, H., Pal, A., Mehta, A., Nagasundaram, E., Lees, J. and Mirshekar-Syahkal, D. 2017. Power amplifier and antenna integration utilizing capacitively coupled feeding mechanism. Presented at: International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, San Diego, CA, USA, 9-14 July 20172017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE pp. 2355-2356., (10.1109/APUSNCURSINRSM.2017.8073220)
- Pal, A., Zhou, H., Mehta, A., Nagasundaram, E., Lees, J. and Mirshekar-Syahkal, D. 2017. Co-design of an antenna-power amplifier RF front-end block without matching network for 2.4 GHz WiFi application. Presented at: 2017 IEEE Radio and Wireless Symposium (RWS), Phoenix, AZ, USA, 15-18 January 20172017 IEEE Radio and Wireless Symposium (RWS). IEEE pp. 201-203., (10.1109/RWS.2017.7885987)
- Dong, S., Lees, J. and Tasker, P. J. 2017. A de-embedding network at higher frequency and its error analysis. Presented at: IEEE International Conference on Electronic Information and Communication Technology (ICEICT), Harbin, China, 20-22 Aug 2016IEEE International Conference on Electronic Information and Communication Technology (ICEICT). IEEE pp. 512-514., (10.1109/ICEICT.2016.7879754)
- Chaudhary, M. A., Memon, Z. A., Yusoff, Z., Lees, J., Benedikt, J. and Tasker, P. J. 2017. Characterization of baseband electrical memory in microwave devices using multi-tone measurement system. Presented at: 2016 16th Mediterranean Microwave Symposium (MMS), 14-16 November 201616th Mediterranean Microwave Symposium (MMS), 2016. IEEE pp. 1., (10.1109/MMS.2016.7803811)
- Dong, S., Tasker, P. J., Wang, G. and Lees, J. 2016. A practicable de-embedding network at higher frequency of a packaged GaN device. Presented at: 2016 IEEE MTT-S International Wireless Symposium (IWS), 14-16 March 2016IEEE MTT-S International Wireless Symposium (IWS), 2016. IEEE pp. 1., (10.1109/IEEE-IWS.2016.7585473)
- Yusoff, Z., Annuar, F. M., Kung, F., Hashim, S. J., Lees, J. and Cripps, S. C. 2016. The effect of tracking generator efficiency to overall RF power amplifier system efficiency. Presented at: 2016 IEEE International Conference on Semiconductor Electronics (ICSE), 17-19 August 20162016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE pp. 344-347., (10.1109/SMELEC.2016.7573662)
- Williams, C. F. et al. 2016. What the deep sea can tell us about microwaves. Presented at: International Microwave Symposium IMS, San Francisco, California, 22-27 May 2016Microwave Symposium (IMS), 2016 IEEE MTT-S International. IEEE, (10.1109/MWSYM.2016.7540432)
- Chaudhary, M. A., Lees, J., Benedikt, J. and Tasker, P. J. 2016. Modulated waveform measurement and engineering system. Presented at: 2015 2nd International Conference on Electronics and Communication Systems (ICECS), Cairo, Egypt, 6-9 December 20152015 IEEE International Conference on Electronics, Circuits, and Systems (ICECS 2015). Institute of Electrical and Electronics Engineers (IEEE) pp. 252-255., (10.1109/ICECS.2015.7440296)
- Imtiaz, A., Hartley, J., Choi, H. and Lees, J. 2015. A high power high efficiency integrated solid-state microwave heating structure for portable diagnostic healthcare applications. Presented at: IEEE MTT-S 2014 IEEE International Microwave Workshop Series on RF and Wireless Technologies for Biomedical and Healthcare Applications, London, 8-10 December 20142014 IEEE MTT-S international microwave workshop series on RF and wireless technologies for biomedical and healthcare applications (IMWS-Bio). IEEE pp. 1-3., (10.1109/IMWS-BIO.2014.7032437)
- Hartley, J., Lees, J., Cuenca, J. and Choi, H. 2014. Assessment of machine oil quality by microwave cavity perturbation method. Presented at: 2014 International Symposium on Information Technology Convergence (ISITC 2014), Jeonju, Republic of Korea, 30-31 October 2014.
- Koh, M., Bell, J. J., Williams, D., Patterson, A., Lees, J., Root, D. E. and Tasker, P. J. 2014. Frequency scalable large signal transistor behavioral model based on admittance domain formulation. Presented at: International Microwave Symposium, Tampa, Florida, 1-6 June 20142014 IEEE MTT-S International Microwave Symposium (IMS). Picastaway, NJ: IEEE pp. 1-3., (10.1109/MWSYM.2014.6848287)
- A Mokhti, Z. B., Tasker, P. J. and Lees, J. 2014. Correlation analysis between a VNA-based passive load pull system and an oscilloscope-based active load pull system: a case study. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 6 June 201483rd ARFTG Microwave Measurement Conference (ARFTG), 2014. pp. 1-4., (10.1109/ARFTG.2014.6899535)
- Ogboi, F. L. et al. 2014. Investigation of various envelope complexity linearity under modulated stimulus using a new envelope formulation approach. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 1 - 6 June 2014Compound Semiconductor Integrated Circuit Symposium (CSICs), 2014 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2014.6978563)
- Yang, F., Lees, J., Choi, H., Yu, H. and Tasker, P. J. 2014. Continuous class BJ power amplifier with DGS output matching. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, USA, 6 June 2014Microwave Symposium (IMS), 2014 IEEE MTT-S International. IEEE pp. 1-4., (10.1109/MWSYM.2014.6848562)
- A Mokhti, Z. B., Tasker, P. J. and Lees, J. 2014. Using waveform engineering to optimize class-F power amplifier performance in an envelope tracking architecture. Presented at: 44th European Microwave Conference (EuMC) 2014, Rome, Italy, 6-9 October 201444th European Microwave Conference (EuMC 2014). IEEE pp. 1301-1304., (10.1109/EuMC.2014.6986682)
- Aldoumani, A., Williams, T., Lees, J. and Tasker, P. J. 2014. Enhanced vector calibration of load-pull measurement systems. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, FL, USA, 6 June 2014ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE pp. 1-4., (10.1109/ARFTG.2014.6899508)
- Ogboi, F. L. et al. 2014. High bandwidth investigations of a baseband linearization approach formulated in the envelope domain under modulated stimulus. Presented at: European Microwave Conference (EuMC) 2014, Rome, Italy, 6-9 October 2014European Microwave Conference (EuMC), Vol. 44. IEEE pp. 1305-1308., (10.1109/EuMC.2014.6986683)
- Mokhti, Z. A., Tasker, P. J. and Lees, J. 2014. Using waveform engineering to optimize Class-F power amplifier performance in an envelope tracking architecture. Presented at: 9th European Microwave Integrated Circuit Conference (EuMIC), Rome, Italy, 6-7 Octpber 2014European Microwave Integrated Circuit Conference (EuMIC), 2014 9th. IEEE pp. 357-360., (10.1109/EuMIC.2014.6997866)
- Mokhti, Z. A., Tasker, P. J. and Lees, J. 2014. Analyzing the improvement in efficiency through the integration of class-F power amplifiers compared to class-AB in an envelope tracking architecture. Presented at: 26th International Teletraffic Congress (ITC), Karlskrona, Sweden, 9-11 September 2014Teletraffic Congress (ITC), 2014 26th International. pp. 1-4., (10.1109/ITC.2014.6932967)
- Ogboi, F. L. et al. 2014. Sensitivity of AM/AM linearizer to AM/PM distortion in devices. Presented at: 83rd ARFTG Microwave Measurement Conference 2014, Tampa, FL, USA, 6 June 2014ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE pp. 1-4., (10.1109/ARFTG.2014.6899507)
- Schmid, U. et al. 2013. Hybrid energy storage system for wireless sensor node powered by aircraft specific thermoelectric energy harvesting. Presented at: Smart Sensors, Actuators, and MEMS VI, Grenoble, France, 24 April 2013Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI, Vol. 8763. SPIE pp. 876307., (10.1117/12.2017691)
- Featherston, C., Holford, K. M., Pullin, R., Lees, J., Eaton, M. J. and Pearson, M. R. 2013. An autonomous structural health monitoring solution. Presented at: Microtechnologies 2013, Grenoble, France, 24-26 April 2013Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI. Society of Photo-Optical Instrumentation Engineers (SPIE) pp. 876302., (10.1117/12.2018401)
- Koh, M., Bell, J. J., Williams, D., Patterson, A., Wohlmuth, W., Lees, J. and Tasker, P. J. 2013. X-band MMIC scalable large signal model based on unit cell behavioral data model and passive embedding network. Presented at: International Microwave Symposium, Seattle, WA, 2-7 June 20132013 IEEE MTT-S International Microwave Symposium Digest (IMS). Picastaway, NJ: IEEE pp. 1-4., (10.1109/MWSYM.2013.6697424)
- Aldoumani, A., Tasker, P. J., Saini, R. S., Bell, J. J., Williams, T. and Lees, J. 2013. Operation and calibration of VNA-based large signal RF I-V waveform measurements system without using a harmonic phase reference standard. Presented at: ARFTG Microwave Measurement Conference (ARFTG), Seattle, WA, 7-7 June 20132013 81st ARFTG Microwave Measurement Conference (ARFTG). Picastaway, NJ: IEEE pp. 1-4., (10.1109/ARFTG.2013.6579055)
- Ogboi, F. L. et al. 2013. A LSNA configured to perform baseband engineering for device linearity investigations under modulated excitations. Presented at: 43rd European Microwave Conference, Nuremberg, Germany, 7-10 October 2013Proceedings of the 43rd European Microwave Conference. pp. 684-687.
- Chaudhary, M. A., Memon, Z. A., Lees, J., Benedikt, J. and Tasker, P. J. 2013. Investigation of baseband electrical memory effects on the dynamic characteristics of power transistors. Presented at: 2013 16th International Multi Topic Conference (INMIC), Lahore, Pakistan, 19-20 December 2013Multi Topic Conference (INMIC), 2013 16th International. IEEE pp. 106-109., (10.1109/INMIC.2013.6731333)
- Chaudhary, M. A., Lees, J., Benedikt, J. and Tasker, P. J. 2013. Reduction of baseband electrical memory effects using broadband active baseband load-pull. Presented at: 2013 IEEE International Wireless Symposium (IWS), Beijing, China, 14-18 April 2013Wireless Symposium (IWS), 2013 IEEE International. IEEE pp. 1-4., (10.1109/IEEE-IWS.2013.6616709)
- Hone, T. M. et al. 2013. Inverse active load-pull in an inverse Doherty amplifier. Presented at: 2013 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications, Santa Clara, CA, USA, 20 Jauary 2013Power Amplifiers for Wireless and Radio Applications (PAWR), 2013 IEEE Topical Conference on. IEEE pp. 4-6., (10.1109/PAWR.2013.6490170)
- Pearson, M., Lees, J., Featherston, C. and Pullin, R. 2013. 9th international conference on advances in experimental mechanics. Presented at: 9th International Conference on Advances in Experimental Mechanics, Cardiff, Wales, 3 - 5 September 2013.
- Bensmida, S. et al. 2012. Nonlinear envelope tracking for efficiency optimization of power amplifiers. Presented at: 7th European Microwave Integrated Circuits Conference (EuMIC) 2012, Amsterdam, The Netherlands, 29-30 October 20127th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE pp. 480-483.
- McGenn, W., Choi, H., Lees, J., Uren, M. J., Benedikt, J. and Tasker, P. J. 2012. Development of a RF waveform stress test procedure for GaN HFETs subjected to infinite VSWR sweeps. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259725)
- Carrubba, V. et al. 2012. Continuous-ClassF3 power amplifier mode varying simultaneously first 3 harmonic impedances. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6258343)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A 40W push-pull power amplifier for high efficiency, decade bandwidth applications at microwave frequencies. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest (MTT, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259418)
- Tasker, P. J., Carrubba, V., Wright, P., Lees, J., Benedikt, J. and Cripps, S. C. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS), La Jolla, CA, USA, 14-17 October 2012Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2012.6340048)
- Mimis, K., Morris, K. A., Beach, M. A., McGeehan, J. P., Lees, J., Benedikt, J. and Tasker, P. J. 2012. Overlapped segment piece-wise polynomial pre-distortion for the linearisation of power amplifiers in the presence of high PAPR OFDM signals. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. pp. 1-3., (10.1109/MWSYM.2012.6259543)
- Akmal, M. et al. 2012. Characterization of electrical memory effects for complex multi-tone excitations using broadband active baseband load-pull. Presented at: 7th European Microwave Integrated Circuits Conference, Amsterdam, The Netherlands, 29-30 October 20127th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE pp. 885-888.
- Yusoff, Z. B., Akmal, M., Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. The benefit of GaN characteristics over LDMOS for linearity improvement using drain modulation in power amplifier system. Presented at: 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, Vienna, Austria, 18-19 April 20112011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE pp. 109-112., (10.1109/INMMIC.2011.5773334)
- Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. A novel highly efficient broadband continuous class-F RFPA delivering 74% average efficiency for an octave bandwidth. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 20112011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 350-353., (10.1109/MWSYM.2011.5972701)
- Yusoff, Z. B., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. Linearity improvement in RF power amplifier system using integrated Auxiliary Envelope Tracking system. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1752-1755., (10.1109/MWSYM.2011.5972769)
- FitzPatrick, D., Saini, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. A waveform engineering approach to the design of improved efficiency wideband MMIC amplifiers. Presented at: Wireless and Microwave Technology Conference (WAMICON), 2011 IEEE 12th Annual., Clearwater Beach, FL, USA, 18-19 April 20112011 IEEE 12th Annual Wireless and Microwave Technology Conference (WAMICON), Clearwater Beach, FL, 18-19 April 2011. Los Alamitos, CA: IEEE pp. 225-230., (10.1109/WAMICON.2011.5872859)
- Akmal, M. et al. 2011. Linearity enhancement of GaN HEMTs under complex modulated excitation by optimizing the baseband impedance environment. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1747-1750., (10.1109/MWSYM.2011.5972833)
- Smith, R. M., Cripps, S. C., Tasker, P. J., Benedikt, J. and Lees, J. 2011. A design methodology for the realization of multi-decade baluns at microwave frequencies. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1204-1208., (10.1109/MWSYM.2011.5972702)
- Bell, J. J., Saini, R., Woodington, S. P., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Behavioral model analysis using simultaneous active fundamental load-pull and harmonic source-pull measurements at X-band. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International. New York: IEEE pp. 982-986., (10.1109/MWSYM.2011.5972803)
- Saini, R. et al. 2011. High speed non-linear device characterization and uniformity investigations at X-band frequencies exploiting behavioral models. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034552)
- Carrubba, V. et al. 2011. High-speed device characterization using an active load-pull system and waveform engineering postulator. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034553)
- Canning, T. A. J., Almuhaisen, A., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Utilization of RF I-V waveform load-pull information to identify the role FET knee profile has on locating the efficiency maxima. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183864)
- Saini, R., Bell, J. J., Williams, T., Lees, J., Benedikt, J. and Tasker, P. J. 2011. Interpolation and extrapolation capabilities of non-linear behavioural models. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183865)
- Carrubba, V. et al. 2011. Exploring the Design Space for Broadband PAs using the Novel "Continuous Inverse Class-F Mode". Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 41st European Microwave Conference (EuMC). IEEE pp. 333-336.
- Hone, T. et al. 2011. Optimized load modulation in a doherty amplifier using a current injection technique. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 296-299.
- Akmal, M. et al. 2011. An enhanced modulated waveform measurement system for the robust characterization of microwave devices under modulated excitation. Presented at: Microwave Integrated Circuits Conference (EuMIC), 2011 European, Manchester, 10-11 October 2011Microwave Integrated Circuits Conference (EuMIC), 2011 European. IEEE pp. 180-183.
- Paynter, M. et al. 2011. Non-linear large signal PA modelling for switching-mode operation (class-F/continuous class-F). Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 152-155.
- Almuhaisen, A., Lees, J., Cripps, S. C., Tasker, P. J. and Benedikt, J. 2011. Wide band high-efficiency power amplifier design. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 184-187.
- Clarke, A. L., Akmal, M., Lees, J., Tasker, P. J. and Benedikt, J. 2010. Investigation and analysis into device optimization for attaining efficiencies in-excess of 90% when accounting for higher harmonics. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 1114-1117., (10.1109/MWSYM.2010.5517222)
- Akmal, M. et al. 2010. The effect of baseband impedance termination on the linearity of GaN HEMTs. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561636. pp. 1046-1049.
- Akmal, M. et al. 2010. The impact of baseband electrical memory effects on the dynamic transfer characteristics of microwave power transistors. Presented at: 2010 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC), Gothenburg, Sweden. Vol. 548011. pp. 148-151.
- Woodington, S. P., Saini, R., Williams, D., Lees, J., Benedikt, J. and Tasker, P. J. 2010. Behavioral model analysis of active harmonic load-pull measurements. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 2010Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International. New York: IEEE pp. 1688-1691., (10.1109/MWSYM.2010.5517261)
- Almuhaisen, A., Wright, P. T., Lees, J., Tasker, P. J., Cripps, S. C. and Benedikt, J. 2010. Novel wide band high-efficiency active harmonic injection power amplifier concept. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 664-667., (10.1109/MWSYM.2010.5514759)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. 2010. Exploitation of active load-pull and DLUT models in MMIC design. Presented at: IEEE Radio Frequency Integrated Circuits Symposium, Anaheim, CA, USA, 23-25 May 2010Proceedings of the 2010 IEEE Radio Frequency Integrated Circuits Symposium May 23-25, 2010, Anaheim, California, USA. Piscataway, NJ: IEEE pp. 487-490., (10.1109/RFIC.2010.5477406)
- Naylon, A. J. et al. 2010. Efficient Microwave heating and dielectric characterization of microfluidic systems. Presented at: Proceedings of MicroTAS 2010, Groningen, The Netherlands. pp. 2092-2094.
- Bensmida, S. et al. 2010. Generic pre-distortion of a Class-J Power amplifier. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561648. pp. 1022-1025.
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2010. The continuous Class-F Mode mode power amplifier. Presented at: European Microwave Conference (EuMC) 2010, Paris, France. Vol. 561630. pp. 1674-1677.
- Lees, J. et al. 2010. Waveform engineering applied to linear-efficient PA design. Presented at: 2010 IEEE 11th Annual Wireless and Microwave Technology Conference (WAMICON 2010), Melbourne Beach, USA, 12-13 April, 2010. Vol. 546184., (10.1109/WAMICON.2010.5461847)
- Saini, R., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. J. 2010. An intelligence driven active loadpull system. Presented at: 75th ARFTG Microwave Measurement Conference: Measurement of Modulated Signals for Communications, Anaheim, USA. Vol. 549632.
- Akmal, M. et al. 2010. Minimization of baseband electrical memory effects in GaN HEMTs using active IF load-pull. Presented at: Asia-Pacific Microwave Conference (22nd : 2010), Yokahama-shi, Japan, 7-10 December 20102010 Asia-Pacific Microwave Conference proceedings : APMC 2010 : Dec. 7-10, Yokohama, Japan. Tokyo, Japan: Institute of Electronics, Information and Communication Engineers (IEICE) pp. 5-8.
- Fitzpatrick, D. M., Lees, J., Sheikh, A., Benedikt, J. and Tasker, P. J. 2009. Systematic investigation of the impact of harmonic termination in the efficiency performance of above octave bandwidth microwave amplifiers. Presented at: European Microwave Conference, 2009 (EuMC 2009), Rome, Italy, 29 September - 1 October 2009European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications pp. 1445-1448.
- Sheikh, A., Lees, J., Benedikt, J. and Tasker, P. J. 2009. Utilization of a measurement based CAD tool for enhanced pa design investigations. Presented at: 38th European Microwave Conference, 2008 (EuMC 2008), Amsterdam, The Netherlands, 27-31 October 2008Proceedings of the 38th European Microwave Conference, 2008 (EuMC 2008). Los Alamitos, CA: IEEE pp. 1671-1674., (10.1109/EUMC.2008.4751795)
- Hashmi, M. S., Clarke, A. L., Woodington, S. P., Lees, J., Benedikt, J. and Tasker, P. 2009. Electronic Multi-Harmonic Load-Pull System for Experimentally Driven Power Amplifier Design Optimization. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, USA. pp. 1549-1552.
- Wright, P. T., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2009. An Efficient, Linear, Broadband Class-J-Mode PA Realised Using RF. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, MA, USA, 7-12 June 2009IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE pp. 653-656., (10.1109/MWSYM.2009.5165781)
- Bensmida, S. et al. 2009. Power amplifier memory-less pre-distortion for 3GPP LTE application. Presented at: European Microwave Conference, 2009 (EuMC 2009), Rome, Italy, 29 September - 1 October 2009European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications pp. 1433-1436.
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. 2008. Reduction of electrical baseband memory effect in high-power LDMOS devices using optimum termination for IMD3 and IMD5 using active load-pull. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 415-418., (10.1109/MWSYM.2008.4633191)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J. and Tasker, P. 2008. Large signal device characterisation using active load-pull for improved MMIC design. Presented at: IET Seminar on RF and Microwave IC Design, London, UK. IET pp. 1-7.
- Lees, J., Williams, T., Woodington, S., McGovern, P., Cripps, S. C., Benedikt, J. and Tasker, P. 2008. Demystifying Device related Memory Effects using Waveform Engineering and Envelope Domain Analysis. Presented at: 38th European Microwave Conference 2008 (EuMC 2008), Amsterdam, The Netherlands. pp. 753-756., (10.1109/EUMC.2008.471562)
- Williams, T., Mojon, O., Woodington, S. P., Lees, J., Barciela, M. F., Benedikt, J. and Tasker, P. J. 2008. A robust approach for comparison and validation of large signal measurement systems. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 257-260., (10.1109/MWSYM.2008.4633152)
- Woodington, S. P. et al. 2008. A novel measurement based method enabling rapid extraction of a RF waveform look-up table based behavioural model. Presented at: IEEE MTT-S International Microwave Symposium Digest, Atlanta, USA. pp. 1453-1456., (10.1109/MWSYM.2008.463305)
- Wright, P. T., Lees, J., Tasker, P. J. and Benedikt, J. 2008. GaN power transistors in narrow and wide bandwidth applications. Presented at: IET Seminar on Wideband Receivers and Components, London, UK. pp. 1.
- Alghanim, A., Lees, J., Wiliams, T., Benedikt, J. and Tasker, P. 2007. Investigation of electrical base-band memory effects in high power 20w LDMOS power amplifiers. Presented at: 37th European Microwave Conference, Munich, Germany. pp. 48-51., (10.1109/EUMC.2007.4405122)
- Sheikh, A., Tasker, P. J., Lees, J. and Benedikt, J. 2007. The impact of system impedance on the characterisation of high power devices. Presented at: 37th European Microwave Conference (EuMC), Munich, Germany. pp. 949-952., (10.1109/EUMC.2007.4405315)
- Alghanim, A., Lees, J., Williams, T., Benedikt, J. and Tasker, P. J. 2007. Using active IF load-pull to investigate electrical base-band induced memory effects in high-power LDMOS transistors. Presented at: Asia-Pacific Microwave Conference (APMC 2007), Bangkok, Thailand. IEEE pp. 1-4., (10.1109/APMC.2007.4554737)
- Mayer, M., Arthaber, H., Magerl, G., Kother, D., Lees, J., Benedikt, J. and Tasker, P. 2006. Advanced load pull systems. Presented at: The Institution of Engineering and Technology Seminar on High Efficiency Power Amplifier Design for Next Generation Wireless Applications, Cambridge, UK. pp. 27-54.
- Aubrey, A. J., Hicks, Y. A., Lees, J. and Chambers, J. A. 2006. Using the bi-modality of speech for convolutive frequency domain blind source separation. Presented at: Proceedings of IMA 7th International Conference on Mathematics in Signal Processing, Cirencester, UK.
- Lees, J., Sheikj, A., Benedikt, J. and Tasker, P. 2006. The Design of a Gallium Nitride Doherty Amplifier using Waveform Measurements and Active Harmonic Load-Pull. Presented at: 2006 International Workshop on Integrated Nonlinear Microwave and Millimeter-Wave Circuits, Aveiro, Portugal. pp. 26-29.
- Aboush, Z., Lees, J., Benedikt, J. and Tasker, P. J. 2005. Active harmonic load-pull system for characterising highly mismatched high power transistors. Presented at: IEEE MTT-S International Microwave Symposium Digest 2005, 2005. , (10.1109/MWSYM.2005.1516920)
- Aboush, Z. et al. 2005. High power active harmonic load-pull system for characterisation of high power 100-Watt transistors. Presented at: 35th European Microwave Conference, Paris, France, Vol. 1. pp. 609-612., (10.1109/EUMC.2005.1608930)
- Lees, J. et al. 2005. A comparison of load-pull measurement results of a 4W Phemt involving five European laboratories. Presented at: European Gallium Arsenide and Other Semiconductor Application Symposium, Paris, France, 3-4 October, 2005Proceedings of the European Gallium Arsenide and Other Semiconductor Application Symposium Paris, France,3-4 October, 2005. IEEE pp. 321-324.
- Lees, J. et al. 2005. Characterisation of an experimental gallium nitride microwave Doherty amplifier. Presented at: 35th European Microwave Conference, Paris, France, 4-6 October 200535th European Microwave Conference: conference proceedings. Horizon House
- Lees, J., Haczewski, J., Benedikt, J. and Tasker, P. 2004. An automated multi-stimulus measurement system for characterising multi-device amplifiers. Presented at: 34th European Microwave Conference, Amsterdam, The Netherlands, Vol. Nov-15. pp. 435-438.
- Lees, J., Goss, M., Benedikt, J. and Tasker, P. 2003. Single-tone optimisation of an adaptive-bias Doherty structure. Presented at: Microwave Symposium Digest, IEEE MTT-S International, Philadelphia, USA, 8-13 June 2003Microwave Symposium Digest, IEEE MTT-S International, Vol. 3. IEEE pp. 2213-2216., (10.1109/MWSYM.2003.1210604)
Thesis
- Lees, J. 2006. Doherty amplifier structures for modern microwave communication systems. PhD Thesis, Cardiff University.
Ymchwil
Rwy'n perthyn i'r Ganolfan Peirianneg Amledd Uchel (CHFE), grŵp ymchwil sydd wedi canolbwyntio'n draddodiadol ac yn llwyddiannus ei weithgareddau ymchwil ar systemau cyfathrebu microdon masnachol, cymwysiadau lled-ddargludyddion cyfansawdd ac, yn fwy diweddar, strwythurau cyseiniant ar gyfer synhwyro ac aflonyddu.
Electroneg lled-ddargludyddion cyfansawdd - Ar hyn o bryd mae'r CHFE yn arwain nifer o brosiectau ymchwil arloesol; consortiwm a ariennir gan EPSRC, sy'n cynnwys nifer o bartneriaid academaidd, datblygu modiwlau RF olrhain amlen lled band uchel (ET) effeithlonrwydd uchel ar gyfer systemau cyfathrebu 5G, sy'n gofyn am integreiddio electroneg RF a baseband yn agos, gan ddefnyddio'r un dechnoleg ddyfais ddelfrydol ar yr un swbstrad GaN-on-silicon. Arweiniodd y CHFE hefyd brosiect cadwyn Gyflenwi RF-GaN mawr, GaNforCS, a ariannwyd gan ERDF drwy Lywodraeth Cymru. Roedd y prosiect yn cynnwys 10 partner diwydiannol, gan drosglwyddo dealltwriaeth a gwybodaeth ymchwil i brosesau diwydiannol ar gyfer cynhyrchu cyfaint, gan alluogi ffynhonnell y DU o ddyfeisiau RF-GaN ar gyfer cymwysiadau cyfathrebu, diogelwch a gofal iechyd.
Gwresogi a tharfu microdon cyflwr solet - Mae Prifysgol Caerdydd yn aelod o'r gynghrair ynni amledd radio (RFEA), consortiwm Ewropeaidd sy'n hyrwyddo'r defnydd o dechnoleg lled-ddargludyddion cyflwr solet ar gyfer cymwysiadau gwresogi a tharfu domestig a diwydiannol y farchnad dorfol. Mae ymchwil gyfredol yn archwilio'r syniad o wresogi cyflwr solet aml-fwydo ar gyfer halltu cyfansoddion â chymorth microdon. Mae manteision sylweddol sy'n gysylltiedig â'r union reolaeth y gellir ei chyflawni trwy wresogi microdon cyflwr cadarn o'i gymharu â'r dulliau traddodiadol, magnetron sy'n seiliedig ac awtoclaf.
Systemau cymorth microdon ar gyfer gofal iechyd - Rwyf wedi bod yn ymwneud â nifer o brosiectau ymchwil cydweithredol gyda'r Ysgolion Deintyddiaeth a fferylliaeth, gan edrych ar ffyrdd y gallwn ddefnyddio maes trydanol microdon gymhwysol i a) atal ffurfio a thwf bioffilmiau gwrth-ficrobaidd, a b) amharu ar gelloedd bacteriol a sborau i ddatgelu DNA ar gyfer gwella canfod desiese gwrthsefyll gwrthficrobal yn gyflym. Un enghraifft sy'n arbennig o bwysig o ran ei effaith bosibl, yw prosiect y Phoenix yn brosiect porth prifysgol yng Nghaerdydd lle mae'r brifysgol yn gweithio gyda chydweithwyr yn Namibia i fynd i'r afael â rhai o'r prif broblemau gofal iechyd y mae'r wlad yn eu hwynebu ar hyn o bryd. Pryder arbennig yw lledaeniad twbercwlosis sy'n gwrthsefyll gwrthfiotigau gyda dros 200,000 o achosion gweithredol ar unrhyw un adeg. Mae trin y clefyd yn arbennig o heriol gan nad oes gan y dulliau diagnostig presennol sensitifrwydd a chyflymder ac mae angen mynediad at seilwaith fel prif gyflenwad trydan. O gofio bod llawer o'r unigolion yr effeithir arnynt yn byw ffordd o fyw ffordd grwydrol, mewn ardaloedd anghysbell o ganolfannau poblogaeth mawr, mae mynediad amserol at ofal iechyd yn her.
Mewn cydweithrediad ar y cyd, mae ysgolion Peirianneg a Fferylliaeth yn datblygu dull gofal amser real sy'n seiliedig ar ficrodon sy'n gallu canfod amrywiaeth o bathogenau, gan gynnwys twbercwlosis, o fewn amserlen sy'n caniatáu i'r claf gael diagnosis a thriniaeth briodol yn ystod yr un ymweliad gofal iechyd. Er mwyn datblygu'r gallu hwn, ein nod yw mynd i'r afael â thair her dechnegol gysylltiedig;
- Datblygu system cipio ynni syml a chadarn sy'n gallu cefnogi gweithrediad yr assay mewn ardaloedd yn Namibia o bell o bŵer prif gyflenwad
- System ymyrraeth microdon pŵer isel sy'n gallu cyfryngu rhyddhau DNA targed o ystod o samplau clinigol.
- Dull llif unffordd syml i'w ddarllen, pathogen-benodol
Mae'r platfform tarfu microdon yn seiliedig ar electroneg microdon solet-wladwriaeth a cheudodau microdon cyseiniant un-modd bach sy'n canolbwyntio maes trydanol pwls o fewn sampl sy'n cynnwys bacteria planctonig neu sborau bacteriol, er mwyn lysio celloedd a rhyddhau DNA targed.
Mae'r defnydd o electroneg microdon cyflwr solid yn allweddol i lwyddiant y prosiect hwn, ac yn bwysig yn caniatáu ystyried datrysiadau batri ac ynni adnewyddadwy foltedd isel, sy'n addas ar gyfer defnyddio caeau o bell.
Mae'r caledwedd microdon yn cael ei optimeiddio'n barhaus, ac mae ymchwil ddiweddar a gynhaliwyd yn Ysgol Peirianneg Caerdydd wedi dangos ei bod yn bosibl lleihau maint, pwysau ac, yn bwysig, y lefelau pŵer microdon gofynnol yn ddramatig, fel bod y gofyniad pŵer ar gyfer echdynnu DNA bellach yn debyg i'r hyn a ddarperir gan ffôn symudol.
Mae'r datblygiadau hyn, ynghyd â'r technegau dylunio mwyhadur microdon effeithlonrwydd uchel a arloeswyd ym Mhrifysgol Caerdydd, bellach yn darparu'r posibilrwydd gwirioneddol y gallai'r offeryn diagnostig a ragwelir gael ei bweru'n lleol gan ddefnyddio generaduron solar neu syml â llaw.
Fel rhan o'r gwaith parhaus hwn, ac yn ychwanegol at yr elfennau microdon, byddwn yn anelu at ddatblygu system storio a chynhyrchu ynni syml, symudol, trydanol sy'n gallu bywiogi'r system ddiagnostig yn gyflym. Byddwn wedyn yn ceisio defnyddio'r system gyfun i Namibia ac mewn partneriaeth byddwn yn cydweithwyr o Ysgol Meddygaeth Prifysgol Namibia, yn pennu gallu'r system i ganfod TB yn y maes.
Contractau Ymchwil
Teitl | Pobl | yn Noddi | Hyd Gwerth | |
---|---|---|---|---|
GaNforCS – Gallium Nitraride ar gyfer Cyfathrebu a Diogelwch | Lees J, Elgaid K, Tasker P | WEFO-ERDF | £2.8M | 01/01/2020 - 30/08/2022 |
Dyfeisiau tonnau milimetr aflinol (signal mawr), cylchedau a systemau ar gyfleuster nodweddu dŵr | PJ Tasker, R Quaglia, K Elgaid, J Bell, S Cripps, J Benedikt, J Lees | EPSRC | £1.5M | 01/10/2018 - 01/09/2019 |
mm-tonnau amplifiers pŵer ar gyfer araeau antena gweithredol | Quaglia R, Lees J, Cripps C | Huawei | £73k | 01/11/2018 - 01/11/2019 |
Datblygu rheoli a storio pŵer a chanfod effeithlon a throsglwyddo di-wifr ar gyfer systemau SHM | Featherston C, Lees J, Pullin R | EADS | £200k | 01/10/2011 - 30/09/2014 |
SENors i Hysbysu a Galluogi NeTworks di-wifr | Featherston C, Pullin R, Lees J, Holford K | TSB drwy HW Communications | £143k | 01/01/2014 - 31/12/2016 |
Montagu | Featherston C, Pullin R, Lees J, Holford K | TSB - Innovate UK | £114k | 01/05/2015 - 31/10/2017 |
Dyfais hunan-bwerus ar gyfer monitro iechyd strwythurol diwifr (SANDWICH) | Featherston C, Pullin R, Lees J, Holford, K | TSB | £40k | 01/05/2013 - 31/10/2016 |
RF Power Amplifiers yn seiliedig ar dechnoleg BiCMOS Silicon-Germanium (SiGe) (efrydiaeth) | Tasker P, Lees J | SiGe Semiconductor (Europe) Ltd | £30k | 01/10/2010 - 31/03/2014 |
Cynlluniau llinellol Baseband ar gyfer chwyddseinyddion pŵer effeithlonrwydd uchel | Tasker P, Lees J | Infinion Technologies North America Corp | £35k | 01/01/2015 - 31/12/2017 |
byfferau perfformiad uchel ar gyfer electroneg RF GaN | Tasker P, Lees J | EPSRC | £250k | 01/10/2016 - 31/03/2020 |
DI aml-ddull - ADC | Belcher R, Lees J, Naylon A | SELEX Galileo | £100k | 01/10/2011 - 31/01/2013 |
Nodweddu dyfais effeithlonrwydd uchel ar gyfer OperaNET | Benedikt J, Lees J | Lled-ddargludyddion Freescale | 50000 | 01/10/2008 - 30/09/2011 |
Uwchraddio'r sylfaen offer bach ar gyfer ymchwilwyr gyrfa gynnar yn y Gwyddorau Peirianneg a Ffisegol | Holford K, Whatling G, Lees J, Anderson P I, Brousseau E, Cipcigan L M, Pullin R, Bigot S, Theobald P, Simpson R N, Kawashita L F, Clarke A | EPSRC | 498326 | 01/11/2012 - 31/03/2013 |
Nodweddu Capacitor BST | Lees J | DYFEISIAU ANALOG | 3500 | 10/12/2012 - 09/01/2013 |
Curing Cyfansawdd Effeithlon trwy Brosesu Microdon Deallus | Lees J, Evans SL, Porch A, Eaton M | Canolfan EPSRC ar gyfer Gweithgynhyrchu Arloesol mewn Cyfansoddion - CIMComp, trwy Nottingham | 49069 | 01/05/2015 - 31/10/2015 |
Datblygu celloedd llwyth ymreolaethol trwy ddatblygu electroneg rheoli pŵer, technolegau cyfathrebu diwifr a chynaeafu ynni ar gyfer ystod eang o gymwysiadau monitro | Lees J, Pullin R, Featherston C, Eaton M | KTP a Flintec | 122570 | 01/10/2013 - 30/09/2015 |
Datblygu a gwireddu chwyddseinyddion pŵer newydd, band eang, effeithlonrwydd uchel (efrydiaeth) | Lees J, Tasker P | Lled-ddargludyddion Freescale France SAS | 50000 | 01/01/2012 - 31/12/2014 |
Perfformiad Uchel mwyhadur pŵer ar gyfer radar arae fesul cam a cheisiadau cyfathrebu pwynt i bwynt | Lees J, Tasker P | M / A COM Technology Solutions (UK) Ltd | 45000 | 01/10/2011 - 30/09/2014 |
Integreiddio Mwyhadur Pŵer Perfformiad Uchel gyda Antena Wideband Miniturized ar gyfer Dyfeisiau Cyfathrebu Uchel Effeithlon yn y Dyfodol | Lees J, Tasker P, Cripps S | Ser Cymru NRN AEM Abertawe | 59350 | 01/10/2014 - 30/09/2017 |
Datblygu a gwireddu chwyddseinyddion pŵer effeithlonrwydd uchel band eang newydd | Tasker P, Lees J | Lled-ddargludyddion Freescale France SAS | 50000 | 01/10/2012 - 30/09/2015 |
Electroneg GaN: Dibynadwyedd RF a mecanweithiau tradio | Tasker P, Lees J | EPSRC | 222392 | 01/01/2013 - 31/12/2015 |
Integreiddio cylchedau RF gyda Cyflymder Uchel GaN Newid ar Swbstradau Silicon | Tasker P, Lees J, Benedikt J | EPSRC | 835074 | 01/04/2016 - 31/03/2019 |
Nodweddu a chymharu dyfeisio GaN wedi'i becynnu | Tasker PJ, Benedikt J, Lees J, | Cree Inc | 16931 | 01/05/2008 - 01/09/2008 |
Nodweddu a modelu deinamig HEMTs RF GaN | Tasker PJ, Lees J | Ser Cymru NRN AEM Abertawe | 81300 | 01/10/2014 - 30/09/2017 |
Datblygu system ddiagnostig gyflym iawn sy'n gallu canfod presenoldeb C. difficile mewn sampl glinigol wrth ochr y gwely mewn llai na 10 munud | Baillie L (PHRMY), Lees J, Porch A | Cronfa Partneriaeth Caerdydd | 12022 | 01/09/2014 - 31/08/2015 |
Gwresogi microdon glân a gwyrdd gan ddefnyddio ffiseg cyflwr solet | Cripps, S, Porch A, Lees J | NXP lled-ddargludyddion Iseldiroedd B V | 30000 | 01/10/2011 - 30/09/2014 |
Addysgu
Deuthum yn Gymrawd yr Academi Addysg Uwch yn 2014.
Ar hyn o bryd mae fy addysgu yn rhychwantu pob blwyddyn o raglenni israddedig ac ôl-raddedig a addysgir mewn Peirianneg Drydanol ac Electronig, yn ogystal ag amryw raglenni cyn-sesiwn ac allgymorth.
Rwy'n arwain pedwar modiwl MSc / MEng; Prosiect Ymchwil, HF-RF Peirianneg, CAD Uwch, Ffugio a Phrofi, Dylunio RF a CAD, yn ogystal â modiwl blwyddyn gyntaf; Cyfathrebu analog.
Mae rolau diweddar a chyfredol eraill yn cynnwys:
Tiwtor Blwyddyn 4 – MEng Peirianneg Integredig ac Electronig (cyfredol)
Tiwtor Blwyddyn 1 – Peirianneg Integredig ac Electronig
MSc Tiwtor - Peirianneg Cyfathrebu Di-wifr a Microdon (gan gynnwys amrywiadau – MRes a chynlluniau 2 flynedd)
MSc Tiwtor – Technoleg Cyfathrebu ac Entrepreneuriaeth
MSc Tiwtor – Electroneg Lled-ddargludyddion Cyfansawdd
Bywgraffiad
Dechreuais fy ngyrfa ym 1998 gan ddatblygu datrysiadau olrhain lleoli optegol a GPS gyda QinetiQ, U.K. a daeth yn Beiriannydd Siartredig ym 1999. Derbyniais fy ngraddau MSc. a PhD. o Brifysgol Caerdydd yn 2002 a 2006 yn y drefn honno ac ymunais â'r Ganolfan Peirianneg Amledd Uchel (CHFE) fel Cydymaith Ymchwil ym mis Mehefin 2005. Deuthum yn Ddarlithydd yn 2011 ac yna yn 2016, Uwch Ddarlithydd mewn Nodweddu Microdon Aflinol. Rhwng 2009 a 2010, cefais fy secondio i Mesuro fel Uwch Beiriannydd Caledwedd.
Mae fy rolau academaidd presennol yn cynnwys Pennaeth yr Adran Peirianneg Drydanol ac Electronig, yn ogystal â Thiwtor MEng Blwyddyn 4. Mae ei rolau blaenorol yn cynnwys Cyfarwyddwr Rhaglenni Ôl-raddedig a Addysgir ar gyfer Peirianneg, Tiwtor Blwyddyn 1 ar gyfer Peirianneg Integredig a Thrydanol ac Electronig a Chyfarwyddwr MSc Peirianneg Cyfathrebu Di-wifr a Microdon a'i amrywiadau.
Fy ffocws ymchwil yw datblygu galluoedd mesur a nodweddu microdon aflinol, chwyddseinyddion microdon perfformiad uchel, yn ogystal ag astudio dyfeisiau anllinellol a llinol gan ddefnyddio technegau parth amser ac amlen fodiwlaidd. Daeth fy ngwaith yn y maes hwn i ben gyda'r mwyhadur GaN Doherty a gyhoeddwyd gyntaf, ac mae gweithgareddau mwy diweddar yn ystyried datblygu technegau mesur parth amser a thynnu llwyth newydd pŵer uchel, band eang yn ogystal â thechnegau modiwleiddio cyflenwad deinamig wrth gyflawni effeithlonrwydd uchel a llinoledd uchel mewn mwyhaduron pŵer microdon. Dros y blynyddoedd diwethaf rwyf wedi cymhwyso fy arbenigedd microdon i gymwysiadau meddygol ac eraill, gan gynnwys dylunio mwyhadur pŵer microdon integredig iawn ar gyfer cymwysiadau diagnostig, a chynhyrchu a defnyddio ynni microdon pwls pŵer uchel ar gyfer canfod clostridium difficile.
Ar hyn o bryd rwy'n goruchwylio / goruchwylio dros 10 o fyfyrwyr PhD mewn Peirianneg Microdon a meysydd cysylltiedig. Cynrychiolais Brifysgol Caerdydd (aelod sefydlol) yn rhaglen OperaNET-2 EUREKA Ewropeaidd sy'n lleihau'r defnydd o bŵer mewn rhwydweithiau systemau cyfathrebu symudol.
Anrhydeddau a dyfarniadau
Ym mis Mehefin 2018 dyfarnwyd gwobr Arloesi Busnes Prifysgol Caerdydd i mi am waith gyda chwmni lleol sy'n datblygu celloedd llwyth ymreolaethol pŵer isel.
Gwobr Athro EEE y Flwyddyn – EN3082/782 – 2016/17
Meysydd goruchwyliaeth
Diddordebau Ymchwil Cyfredol
Mae gen i ddiddordeb mewn goruchwylio myfyrwyr PhD ym meysydd
- Effeithlonrwydd uchel Power Mwyhadur Dylunio
- mm-tonnau pŵer mwyhadur dylunio
- Technegau dylunio cylched microdon a thonnau mm
- Cymwysiadau meddygol peirianneg microdon
- Nodweddu microdon a thonnau mm
Myfyrwyr cyfredol
Gradd | Statws | Myfyriwr | Teitl|
---|---|---|---|
Nodweddu lefel dyfais o fwyhaduron pŵer all-raddol | Aleksander Bogusz | Cerrynt | Phd |
Amlen Integredig Olrhain Power Amplifiers ar gyfer cyfathrebu 5G | Alexander Alt | Cerrynt | Phd |
Modelu Anllinellol Seiliedig ar Fesur ar gyfer Dyfeisiau Gweithredol | Zack Costello | Cerrynt | Phd |
Integreiddio Amplifiers Power Perfformiad Uchel gyda Antenâu Wideband Miniaturised ar gyfer Dyfeisiau Cyfathrebu Uchel Effeithlon yn y Dyfodol | Elango Nagasundaram | Cerrynt | Phd |