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Dr Jonny Lees
- Available for postgraduate supervision
Teams and roles for Jonny Lees
Head of Department, Electrical & Electronic Engineering
Reader
Overview
My key research areas are linear-efficient PA design and microwave characterisation with a specific interest in the design and optimisation of High-Efficiency Power Amplifiers. Significant achievements include the first published GaN Doherty amplifier, and more recently, activities considering 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.
My most recent research activities include developement of compound semiconductors devices and circuits for high-frequency electronics, mm-wave characterisation, investigating RF properties of materials, microwave heating and disruption and application of microwave engineering to healthcare and diagnostics.
Publication
2024
- Bogusz, A. et al. 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 2024. Proceedings of IEEE/MTT-S International Microwave Symposium. IEEE. , pp.580-583. (10.1109/IMS40175.2024.10600335)
- Joshi, L. T. et al., 2024. Rapid, point-of-care microwave lysis and electrochemical detection of Clostridioides difficile directly from stool samples. Bioengineering 11 (6) 632. (10.3390/bioengineering11060632)
- 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) e0306738. (10.1371/journal.pone.0306738)
2023
- Li, W. et al., 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 2023. Proceedings of the 2023 IEEE/MTT-S International Microwave Symposium (IMS). IEEE. , pp.203-206. (10.1109/IMS37964.2023.10188039)
- Twigg, J. A. et al. 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. et al., 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
- Ahortor, E. K. et al. 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)
- Alt, A. et al. 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 2020. 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE. , pp.1-3. (10.1109/INMMiC46721.2020.9160186)
- Chen, P. et al. 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)
- 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 2020. 2020 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE. , pp.1-3. (10.1109/INMMiC46721.2020.9160347)
- Chen, P. et al. 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 2020. 2020 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. 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)
- Eblabla, A. et al. 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 2019. 2019 IEEE Asia-Pacific Microwave Conference (APMC). IEEE. , pp.1179-1181. (10.1109/APMC46564.2019.9038731)
- 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)
2019
- Alsahali, S. et al. 2019. Supply modulator ripple in envelope tracking systems - effects and countermeasures. Presented at: 49th European Microwave Conference (EuMC 2019) Paris, France 01-03 October 2019. 2019 49th European Microwave Conference (EuMC). IEEE. , pp.710-713. (10.23919/EuMC.2019.8910890)
- 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. et al. 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. 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)
- Alt, A. et al. 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 2018. 2018 IEEE Wireless Power Transfer Conference (WPTC). IEEE(10.1109/WPT.2018.8639317)
- Bogusz, A. et al. 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 2019. 2019 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)
- Bogusz, A. et al. 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)
- Chaudhary, M. A. et al., 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 2017. Proceedings of 3rd International Conference on Circuits, Systems and Devices (ICCSD). IEEE. , pp.92. (10.1109/ICCSD.2019.8843202)
- Eblabla, A. et al. 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)
- Hamzah, H. et al. 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 2019. 2019 IEEE MTT-S International Microwave Biomedical Conference (IMBioC). IEEE. (10.1109/IMBIOC.2019.8777882)
- Malyshev, D. et al. 2019. Model of microwave effects on bacterial spores. Journal of Applied Physics 125 (12) 124701. (10.1063/1.5085442)
- Mokhti, Z. A. et al., 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)
- 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 2019. IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR). IEEE
- 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) 051412. (10.1117/1.JBO.24.5.051412)
2018
- Alt, A. et al. 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.-.
- Alt, A. et al. 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 2018. Proceedings of the 48th European Microwave Conference. Piscataway, NJ: IEEE. , pp.773-776. (10.23919/EuMC.2018.8541564)
- Bogusz, A. et al. 2018. Power and efficiency continuous modes in saturated GaN HEMT devices. Presented at: Inmmic 2018 Brive-La-Gaillarde, France 5- 6 July 2018.
- Chaudhary, M. A. et al., 2018. Multitone measurement system for linearity investigations of microwave devices. Presented at: International Multi-Topic Conference (Inmic) Lahore, Pakistan 24-26 Nov 2017. International Multi-Topic Conference (Inmic). IEEE. (10.1109/INMIC.2017.8289455)
- Chaudhary, M. A. et al., 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 2018. 2018 5th International Conference on Electrical and Electronic Engineering (ICEEE). IEEE. , pp.219-223. (10.1109/ICEEE2.2018.8391334)
- Chen, P. et al. 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 2018. International Workshop on Integrated Nonlinear Microwave and Millimetre-wave Circuits (INMMIC). IEEE. (10.1109/INMMIC.2018.8429984)
- Hamzah, H. et al. 2018. A compact microwave microfluidic sensor using a re-entrant cavity. Sensors 18 (3) 910. (10.3390/s18030910)
- 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)
- 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 2018. International Microwave Biomedical Conference (IMBioC). IEEE. , pp.199. (10.1109/IMBIOC.2018.8428902)
2017
- Abduljabar, A. A. et al., 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)
- 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 2017. 2017 47th European Microwave Conference (EuMC). IEEE. , pp.464-467. (10.23919/EuMC.2017.8230890)
- Chaudhary, M. A. et al., 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 2016. 16th Mediterranean Microwave Symposium (MMS), 2016. IEEE. , pp.1. (10.1109/MMS.2016.7803811)
- 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 2016. IEEE International Conference on Electronic Information and Communication Technology (ICEICT). IEEE. , pp.512-514. (10.1109/ICEICT.2016.7879754)
- Hefford, S. et al. 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 2017. 2017 47th European Microwave Conference (EuMC). IEEE. , pp.927-929. (10.23919/EuMC.2017.8230997)
- Pal, A. et al., 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 2017. 2017 IEEE Radio and Wireless Symposium (RWS). IEEE. , pp.201-203. (10.1109/RWS.2017.7885987)
- Zhou, H. et al., 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 2017. 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE. , pp.2355-2356. (10.1109/APUSNCURSINRSM.2017.8073220)
2016
- Chaudhary, M. A. et al., 2016. Modulated waveform measurement and engineering system. Presented at: 2015 2nd International Conference on Electronics and Communication Systems (ICECS) Cairo, Egypt 6-9 December 2015. 2015 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)
- Dong, S. et al., 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 2016. IEEE MTT-S International Wireless Symposium (IWS), 2016. IEEE. , pp.1. (10.1109/IEEE-IWS.2016.7585473)
- Williams, C. F. et al. 2016. The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation. Applied Physics Letters 109 (9) 093701. (10.1063/1.4961970)
- 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 2016. Microwave Symposium (IMS), 2016 IEEE MTT-S International. IEEE(10.1109/MWSYM.2016.7540432)
- Yusoff, Z. et al., 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 2016. 2016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE. , pp.344-347. (10.1109/SMELEC.2016.7573662)
- Yusoff, Z. et al., 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
- 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) 213502. (10.1063/1.4921848)
- 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)
- Imtiaz, A. et al. 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 2014. 2014 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)
- Imtiaz, A. et al. 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)
- Mokhti, Z. A. et al., 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)
2014
- 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 2014. 83rd ARFTG Microwave Measurement Conference (ARFTG), 2014. , pp.1-4. (10.1109/ARFTG.2014.6899535)
- 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 2014. 44th European Microwave Conference (EuMC 2014). IEEE. , pp.1301-1304. (10.1109/EuMC.2014.6986682)
- Aldoumani, A. et al. 2014. Enhanced vector calibration of load-pull measurement systems. Presented at: 83rd ARFTG Microwave Measurement Conference 2014 Tampa, FL, USA 6 June 2014. ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE. , pp.1-4. (10.1109/ARFTG.2014.6899508)
- Hartley, J. et al. 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. et al., 2014. Frequency scalable large signal transistor behavioral model based on admittance domain formulation. Presented at: International Microwave Symposium Tampa, Florida 1-6 June 2014. 2014 IEEE MTT-S International Microwave Symposium (IMS). Picastaway, NJ: IEEE. , pp.1-3. (10.1109/MWSYM.2014.6848287)
- 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 2014. Teletraffic Congress (ITC), 2014 26th International. , pp.1-4. (10.1109/ITC.2014.6932967)
- 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 2014. European Microwave Integrated Circuit Conference (EuMIC), 2014 9th. IEEE. , pp.357-360. (10.1109/EuMIC.2014.6997866)
- 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 2014. European Microwave Conference (EuMC). Vol. 44.IEEE. , pp.1305-1308. (10.1109/EuMC.2014.6986683)
- 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 2014. Compound Semiconductor Integrated Circuit Symposium (CSICs), 2014 IEEE. IEEE. , pp.1-4. (10.1109/CSICS.2014.6978563)
- 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 2014. ARFTG Microwave Measurement Conference (ARFTG), 2014 83rd. IEEE. , pp.1-4. (10.1109/ARFTG.2014.6899507)
- Yang, F. et al., 2014. Continuous class BJ power amplifier with DGS output matching. Presented at: 83rd ARFTG Microwave Measurement Conference 2014 Tampa, USA 6 June 2014. Microwave Symposium (IMS), 2014 IEEE MTT-S International. IEEE. , pp.1-4. (10.1109/MWSYM.2014.6848562)
2013
- Aldoumani, A. et al. 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 2013. 2013 81st ARFTG Microwave Measurement Conference (ARFTG). Picastaway, NJ: IEEE. , pp.1-4. (10.1109/ARFTG.2013.6579055)
- Chaudhary, M. A. et al., 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 2013. Multi Topic Conference (INMIC), 2013 16th International. IEEE. , pp.106-109. (10.1109/INMIC.2013.6731333)
- Chaudhary, M. A. et al., 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 2013. Wireless Symposium (IWS), 2013 IEEE International. IEEE. , pp.1-4. (10.1109/IEEE-IWS.2013.6616709)
- Featherston, C. et al. 2013. An autonomous structural health monitoring solution. Presented at: Microtechnologies 2013 Grenoble, France 24-26 April 2013. Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI. Society of Photo-Optical Instrumentation Engineers (SPIE). , pp.876302. (10.1117/12.2018401)
- 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 2013. Power Amplifiers for Wireless and Radio Applications (PAWR), 2013 IEEE Topical Conference on. IEEE. , pp.4-6. (10.1109/PAWR.2013.6490170)
- Koh, M. et al., 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 2013. 2013 IEEE MTT-S International Microwave Symposium Digest (IMS). Picastaway, NJ: IEEE. , pp.1-4. (10.1109/MWSYM.2013.6697424)
- Kural, A. et al. 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)
- 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 2013. Proceedings of the 43rd European Microwave Conference. , pp.684-687.
- Pearson, M. et al. 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.
- 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 2013. Proc. SPIE 8763, Smart Sensors, Actuators, and MEMS VI. Vol. 8763.SPIE. , pp.876307. (10.1117/12.2017691)
- Thangaraj, K. et al. 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)
- Yusoff, Z. et al., 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)
2012
- Akmal, M. et al. 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)
- 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 2012. 7th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE. , pp.885-888.
- Arnold, M. et al., 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)
- 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 2012. 7th European Microwave Integrated Circuits Conference (EuMIC), 2012. Picastaway, NJ: IEEE. , pp.480-483.
- 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 2012. Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE. , pp.1-3. (10.1109/MWSYM.2012.6258343)
- Carrubba, V. et al. 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. et al. 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 2012. Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE. , pp.1-3. (10.1109/MWSYM.2012.6259725)
- Mimis, K. et al., 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 2012. Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. , pp.1-3. (10.1109/MWSYM.2012.6259543)
- 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) 012049. (10.1088/1742-6596/382/1/012049)
- Smith, R. M. et al., 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 2012. Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE. , pp.1-3. (10.1109/MWSYM.2012.6259418)
- Smith, R. M. et al. 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)
- Tasker, P. J. et al. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS) La Jolla, CA, USA 14-17 October 2012. Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE. , pp.1-4. (10.1109/CSICS.2012.6340048)
2011
- 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. Published in: Seigel, P. et al., 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.1747-1750. (10.1109/MWSYM.2011.5972833)
- 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 2011. Microwave Integrated Circuits Conference (EuMIC), 2011 European. IEEE. , pp.180-183.
- Almuhaisen, A. et al. 2011. Wide band high-efficiency power amplifier design. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011 Manchester, UK 10-11 October 2011. Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE. , pp.184-187.
- Bell, J. J. et al. 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 2011. Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International. New York: IEEE. , pp.982-986. (10.1109/MWSYM.2011.5972803)
- Canning, T. A. J. et al. 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 2011. Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE(10.1109/ARFTG78.2011.6183864)
- 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 2011. Proceedings of the 41st European Microwave Conference (EuMC). IEEE. , pp.333-336.
- Carrubba, V. et al. 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)
- 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 2011. Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE(10.1109/ARFTG77.2011.6034553)
- Carrubba, V. et al. 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 2011. 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.350-353. (10.1109/MWSYM.2011.5972701)
- FitzPatrick, D. et al., 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 2011. 2011 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)
- 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 2011. Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE. , pp.296-299.
- 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 2011. Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE. , pp.152-155.
- 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 2011. Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE(10.1109/ARFTG77.2011.6034552)
- Saini, R. et al. 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 2011. Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE(10.1109/ARFTG78.2011.6183865)
- Smith, R. M. et al. 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. Published in: Seigel, P. et al., 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.1204-1208. (10.1109/MWSYM.2011.5972702)
- Yusoff, Z. B. et al. 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 2011. 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE. , pp.109-112. (10.1109/INMMIC.2011.5773334)
- Yusoff, Z. B. et al. 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. Published in: Seigel, P. et al., 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.1752-1755. (10.1109/MWSYM.2011.5972769)
2010
- Akmal, M. et al., 2010. The effect of baseband impedance termination on the linearity of GaN HEMTs. Presented at: European Microwave Conference 2010 Paris, FranceVol. 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, SwedenVol. 548011. , pp.148-151.
- 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 2010. 2010 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.
- Almuhaisen, A. et al. 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 2010. 2010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE. , pp.664-667. (10.1109/MWSYM.2010.5514759)
- Bensmida, S. et al., 2010. Generic pre-distortion of a Class-J Power amplifier. Presented at: European Microwave Conference 2010 Paris, FranceVol. 561648. , pp.1022-1025.
- Carrubba, V. et al., 2010. The continuous Class-F Mode mode power amplifier. Presented at: European Microwave Conference (EuMC) 2010 Paris, FranceVol. 561630. , pp.1674-1677.
- Clarke, A. L. et al. 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 2010. 2010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE. , pp.1114-1117. (10.1109/MWSYM.2010.5517222)
- FitzPatrick, D. M. et al., 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 2010. Proceedings 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)
- Hashmi, M. S. et al. 2010. Agile harmonic envelope load-pull system enabling reliable and rapid device characterization. Measurement Science and Technology 21 (5) 055109. (10.1088/0957-0233/21/5/055109)
- Hashmi, M. S. et al. 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)
- 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)
- 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.
- Saini, R. et al. 2010. An intelligence driven active loadpull system. Presented at: 75th ARFTG Microwave Measurement Conference: Measurement of Modulated Signals for Communications Anaheim, USAVol. 549632.
- Woodington, S. P. et al. 2010. Behavioral model analysis of active harmonic load-pull measurements. Presented at: IEEE MTT-S International Microwave Symposium Anaheim, CA, USA 23-28 May 2010. Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International. New York: IEEE. , pp.1688-1691. (10.1109/MWSYM.2010.5517261)
2009
- 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 2009. European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications. , pp.1433-1436.
- Cripps, S. C. et al. 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)
- Fitzpatrick, D. M. et al. 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 2009. European Microwave Week 2009 - "Science, Progress and Quality at Radiofrequencies": Conference Proceedings. London: Horizon House Publications. , pp.1445-1448.
- Hashmi, M. S. et al., 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.
- Sheikh, A. et al., 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 2008. Proceedings of the 38th European Microwave Conference, 2008 (EuMC 2008). Los Alamitos, CA: IEEE. , pp.1671-1674. (10.1109/EUMC.2008.4751795)
- Wright, P. et al., 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)
- Wright, P. T. et al. 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 2009. IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE. , pp.653-656. (10.1109/MWSYM.2009.5165781)
2008
- Alghanim, A. et al., 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)
- Alghanim, A. et al., 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)
- FitzPatrick, D. M. et al., 2008. Large signal device characterisation using active load-pull for improved MMIC design. Presented at: IET Seminar on RF and Microwave IC Design London, UKIET. , pp.1-7.
- Lees, J. et al. 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. et al., 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. et al. 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. et al., 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)
- Alghanim, A. et al., 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, ThailandIEEE. , pp.1-4. (10.1109/APMC.2007.4554737)
- Sheikh, A. et al., 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)
2006
- Aubrey, A. J. et al., 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. 2006. Doherty amplifier structures for modern microwave communication systems. PhD Thesis , Cardiff University.
- Lees, J. et al. 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.
- Mayer, M. et al., 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.
2005
- 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, FranceVol. 1., pp.609-612. (10.1109/EUMC.2005.1608930)
- Aboush, Z. et al. 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)
- 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, 2005. Proceedings 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 2005. 35th European Microwave Conference: conference proceedings. Horizon House
- Lees, J. et al. 2005. Experimental gallium nitride microwave Doherty amplifier. IEEE Electronic Letters 41 (23), pp.1284-1285. (10.1049/el:20053155)
2004
- Lees, J. et al. 2004. An automated multi-stimulus measurement system for characterising multi-device amplifiers. Presented at: 34th European Microwave Conference Amsterdam, The NetherlandsVol. Nov-15., pp.435-438.
2003
- Lees, J. et al. 2003. Single-tone optimisation of an adaptive-bias Doherty structure. Presented at: Microwave Symposium Digest, IEEE MTT-S International Philadelphia, USA 8-13 June 2003. Microwave Symposium Digest, IEEE MTT-S International. Vol. 3.IEEE. , pp.2213-2216. (10.1109/MWSYM.2003.1210604)
Articles
- Abduljabar, A. A. et al., 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)
- Ahortor, E. K. et al. 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)
- Akmal, M. et al. 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)
- Alghanim, A. et al., 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)
- 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)
- 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)
- Arnold, M. et al., 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)
- Bogusz, A. et al. 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)
- 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) 213502. (10.1063/1.4921848)
- 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)
- Carrubba, V. et al. 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)
- Carrubba, V. et al. 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)
- Chen, P. et al. 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)
- Chen, P. et al. 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)
- Cripps, S. C. et al. 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)
- Eblabla, A. et al. 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)
- Hamzah, H. et al. 2018. A compact microwave microfluidic sensor using a re-entrant cavity. Sensors 18 (3) 910. (10.3390/s18030910)
- 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)
- Hashmi, M. S. et al. 2010. Agile harmonic envelope load-pull system enabling reliable and rapid device characterization. Measurement Science and Technology 21 (5) 055109. (10.1088/0957-0233/21/5/055109)
- Hashmi, M. S. et al. 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)
- 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)
- Imtiaz, A. et al. 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)
- Joshi, L. T. et al., 2024. Rapid, point-of-care microwave lysis and electrochemical detection of Clostridioides difficile directly from stool samples. Bioengineering 11 (6) 632. (10.3390/bioengineering11060632)
- Kural, A. et al. 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)
- Lees, J. et al. 2005. Experimental gallium nitride microwave Doherty amplifier. IEEE Electronic Letters 41 (23), pp.1284-1285. (10.1049/el:20053155)
- Malyshev, D. et al. 2019. Model of microwave effects on bacterial spores. Journal of Applied Physics 125 (12) 124701. (10.1063/1.5085442)
- Mokhti, Z. A. et al., 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)
- Mokhti, Z. A. et al., 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)
- 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)
- 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)
- 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) 012049. (10.1088/1742-6596/382/1/012049)
- Sadeque, M. G. et al., 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)
- 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) e0306738. (10.1371/journal.pone.0306738)
- Smith, R. M. et al. 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)
- Thangaraj, K. et al. 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)
- Twigg, J. A. et al. 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)
- 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) 051412. (10.1117/1.JBO.24.5.051412)
- Williams, C. F. et al. 2016. The separated electric and magnetic field responses of luminescent bacteria exposed to pulsed microwave irradiation. Applied Physics Letters 109 (9) 093701. (10.1063/1.4961970)
- Wright, P. et al., 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)
- Yusoff, Z. et al., 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)
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Conferences
- 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 2014. 83rd ARFTG Microwave Measurement Conference (ARFTG), 2014. , pp.1-4. (10.1109/ARFTG.2014.6899535)
- 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 2014. 44th European Microwave Conference (EuMC 2014). IEEE. , pp.1301-1304. (10.1109/EuMC.2014.6986682)
- 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, FranceVol. 1., pp.609-612. (10.1109/EUMC.2005.1608930)
- Aboush, Z. et al. 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)
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- Sheikh, A. et al., 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)
- Smith, R. M. et al., 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 2012. Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE. , pp.1-3. (10.1109/MWSYM.2012.6259418)
- Smith, R. M. et al. 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. Published in: Seigel, P. et al., 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.1204-1208. (10.1109/MWSYM.2011.5972702)
- Tasker, P. J. et al. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS) La Jolla, CA, USA 14-17 October 2012. Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE. , pp.1-4. (10.1109/CSICS.2012.6340048)
- 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 2016. Microwave Symposium (IMS), 2016 IEEE MTT-S International. IEEE(10.1109/MWSYM.2016.7540432)
- 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 2018. International Microwave Biomedical Conference (IMBioC). IEEE. , pp.199. (10.1109/IMBIOC.2018.8428902)
- Williams, T. et al., 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. 2010. Behavioral model analysis of active harmonic load-pull measurements. Presented at: IEEE MTT-S International Microwave Symposium Anaheim, CA, USA 23-28 May 2010. Microwave Symposium Digest (MTT), 2010 IEEE MTT-S International. New York: IEEE. , pp.1688-1691. (10.1109/MWSYM.2010.5517261)
- 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. et al. 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 2009. IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE. , pp.653-656. (10.1109/MWSYM.2009.5165781)
- Wright, P. T. et al. 2008. GaN power transistors in narrow and wide bandwidth applications. Presented at: IET Seminar on Wideband Receivers and Components London, UK, pp.1.
- Yang, F. et al., 2014. Continuous class BJ power amplifier with DGS output matching. Presented at: 83rd ARFTG Microwave Measurement Conference 2014 Tampa, USA 6 June 2014. Microwave Symposium (IMS), 2014 IEEE MTT-S International. IEEE. , pp.1-4. (10.1109/MWSYM.2014.6848562)
- Yusoff, Z. et al., 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 2016. 2016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE. , pp.344-347. (10.1109/SMELEC.2016.7573662)
- Yusoff, Z. B. et al. 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 2011. 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE. , pp.109-112. (10.1109/INMMIC.2011.5773334)
- Yusoff, Z. B. et al. 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. Published in: Seigel, P. et al., 2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE. , pp.1752-1755. (10.1109/MWSYM.2011.5972769)
- Zhou, H. et al., 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 2017. 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting. IEEE. , pp.2355-2356. (10.1109/APUSNCURSINRSM.2017.8073220)
Thesis
- Lees, J. 2006. Doherty amplifier structures for modern microwave communication systems. PhD Thesis , Cardiff University.
Research
I belong to the centre for high-frequency engineering (CHFE), a research group that has traditionally, and sucessfully focussed its research activities on commercial microwave communication systems, applications of compound semiconductors and more recently, resonant structures for sensing and disruption.
Compound semiconductor electronics - The CHFE is currently leading a number of groundbreaking research projects; an EPSRC funded consortium, involving numerous academic partners, developing high-efficiency, high-bandwidth envelope tracking (ET) RF modules for 5G communications systems, that require the close integration of RF and baseband electronics, using the same device technology ideally on the same GaN-on-silicon substrate. The CHFE also led a major RF-GaN Supply chain project, GaNforCS, funded by ERDF via the Welsh Government. The project involved 10 industrial partners, transferring research understanding and know-how into industrial processes for volume production, enabling a UK source of RF-GaN devices for communications, security and healthcare applications.
Solid-state microwave heating and disruption - Cardiff University is a member of the radio frequency energy alliance (RFEA), a European consortium promiting the use of solid-state semiconductor technology for mass-market domestic and industrial heating and disruption applications. Current research explores the idea of multiple-feed solid state heating for microwave assisted curing of composites. There are significant benefits linked to the precise control achievable through solid-state microwave heating compared to the traditional, magnetron based and autoclave approaches.
Microwave assisted systems for healthcare - I have been involved with a number of collaborative research projects with the Schools of Dentistry and pharmacy, looking at ways in which we can use an applied microwave electrical field to a) inhibit the formation and growth of anti-microbial resistant biofilms, and b) the disruption of bacterial cell and spore to expose DNA for enhance rapid detection of antimicrobal resistant desiese. One example that is particulary important in terms of its potential impact, is the The Phoenix project is a Cardiff university gateway project in which the university is working with colleagues in Namibia to address some of the major healthcare problems which the country is currently facing. Of particular concern is the spread of antibiotic resistant tuberculosis with over 200,000 active cases at any one time. Treating the disease is particularly challenging as the current diagnostic methods lack sensitivity and speed and require access to infrastructure such as mains electricity. Given that many of the affected individuals live a nomadic life style, in areas remote from major centres of population, timely access to healthcare is a challenge.
In joint collaboration, the schools of Engineering and Pharmacy are developing a microwave based real-time point of care assay capable of detecting a range of pathogens, including tuberculosis, within a time frame which allows the patient to be diagnosed and appropriately treated during the same healthcare visit. To develop this capability, we aim to address three linked technical challenges;
- The development of a simple and robust energy capture system capable of supporting the operation of the assay in areas of Namibia remote from mains power
- A low-power microwave disruption system capable of mediating the release of target DNA from a range of clinical samples.
- A simple to read, pathogen-specific lateral flow assay
The microwave disruption platform is based on solid-state microwave electronics and small single-mode resonant microwave cavities that focus a pulsed electrical field within a sample containing planktonic bacteria or bacterial spore, in order to lyse cells and liberate target DNA.
The use of solid-state microwave electronics is key to the success of this project, and importantly allows low-voltage battery and renewable energy solutions to be considered, suitble for remote field deployment.
The microwave hardware is continually being optimised, and recent research conducted at Cardiff School of Engineering has demonstrated that it is possible to reduce the size, weight and importantly the required microwave power levels dramatically, such that the power requirement for DNA extraction is now similar to that delivered by a mobile phone handset.
These advances, coupled with the high-efficiency microwave amplifier design techniques pioneered at Cardiff University, now provide the real possibility that the diagnostic tool envisaged could be powered locally using solar or simple hand-crank generators.
As part of this ongoing work, and in addition to the microwave elements, we will aim to develop a simple, mobile, electrical energy generation and storage system capable of quickly energising the diagnostic system. We will then look to deploy the combined system to Namibia and in partnership will colleagues from the school of Medicine of the University of Namibia, determine the ability of the system to detect TB in the field.
Research Contracts
| Title | People | Sponsor | Value | Duration |
|---|---|---|---|---|
| GaNforCS – Gallium Nitride for Communications and Security | Lees J, Elgaid K, Tasker P | WEFO-ERDF | £2.8M | 01/01/2020 - 30/08/2022 |
| Non-linear (large signal) millimetre-wave devices, circuits and systems on-water characterisation facility | PJ Tasker, R Quaglia, K Elgaid, J Bell, S Cripps, J Benedikt, J Lees | EPSRC | £1.5M | 01/10/2018 - 01/09/2019 |
| mm-wave power amplifiers for active antenna arrays | Quaglia R, Lees J, Cripps C | Huawei | £73k | 01/11/2018 - 01/11/2019 |
| Development of power management and storage and efficient detection and wireless transmission for SHM systems | Featherston C, Lees J, Pullin R | EADS | £200k | 01/10/2011 - 30/09/2014 |
| SENsors to Inform and Enable wireless NeTworks | Featherston C, Pullin R, Lees J, Holford K | TSB via 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 |
| Self-powered autonomous device for wireless structural health monitoring (SANDWICH) | Featherston C, Pullin R, Lees J, Holford, K | TSB | £40k | 01/05/2013 - 31/10/2016 |
| RF Power Amplifiers based upon Silicon-Germanium (SiGe) BiCMOS technology (studentship) | Tasker P, Lees J | SiGe Semiconductor (Europe) Ltd | £30k | 01/10/2010 - 31/03/2014 |
| Baseband linearisation schemes for high efficiency power amplifiers | Tasker P, Lees J | Infinion Technologies North America Corp | £35k | 01/01/2015 - 31/12/2017 |
| High performance buffers for RF GaN electronics | Tasker P, Lees J | EPSRC | £250k | 01/10/2016 - 31/03/2020 |
| Multi-Mode DI - ADC | Belcher R, Lees J, Naylon A | SELEX Galileo | £100k | 01/10/2011 - 31/01/2013 |
| High-efficiency device characterisation for OperaNET | Benedikt J, Lees J | Freescale Semiconductor | 50000 | 01/10/2008 - 30/09/2011 |
| Upgrading the small equipment base for early career researchers in the Engineering and Physical Sciences | 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 |
| BST Capacitor characterisation | Lees J | ANALOG DEVICES | 3500 | 10/12/2012 - 09/01/2013 |
| Efficient Composite Curing by Intelligent Microwave Processing | Lees J, Evans SL, Porch A, Eaton M | EPSRC Centre for Innovative Manufacturing in Composites - CIMComp, via Nottingham | 49069 | 01/05/2015 - 31/10/2015 |
| To develop autonomous load cells through the development of power management electronics, wireless communication and energy harvesting technologies for a wide range of monitoring applications | Lees J, Pullin R, Featherston C, Eaton M | KTP and Flintec | 122570 | 01/10/2013 - 30/09/2015 |
| Development and Realisation of Novel, Broadband, High-Efficiency Power Amplifiers (studentship) | Lees J, Tasker P | Freescale Semiconductor France SAS | 50000 | 01/01/2012 - 31/12/2014 |
| High Performance power amplifiers for phased array radar and point to point communication applications | Lees J, Tasker P | M/A COM Technology Solutions (UK) Ltd | 45000 | 01/10/2011 - 30/09/2014 |
| Integrating High-Performance Power Amplifier with Miniturized Wideband Antenna for Highly-Efficient Future Communication Devices | Lees J, Tasker P, Cripps S | Ser Cymru NRN AEM Swansea | 59350 | 01/10/2014 - 30/09/2017 |
| Development and realisation of novel broadband high efficiency power amplifiers | Tasker P, Lees J | Freescale Semiconductors France SAS | 50000 | 01/10/2012 - 30/09/2015 |
| GaN electronics: RF reliability and detradation mechanisms | Tasker P, Lees J | EPSRC | 222392 | 01/01/2013 - 31/12/2015 |
| Integration of RF Circuits with High Speed GaN Switching on Silicon Substrates | Tasker P, Lees J, Benedikt J | EPSRC | 835074 | 01/04/2016 - 31/03/2019 |
| Characterisation and comparison of packaged GaN devises | Tasker PJ, Benedikt J, Lees J, | Cree Inc | 16931 | 01/05/2008 - 01/09/2008 |
| Dynamic Characterisation and modelling of RF GaN HEMTs | Tasker PJ, Lees J | Ser Cymru NRN AEM Swansea | 81300 | 01/10/2014 - 30/09/2017 |
| Develop an ultra rapid diagnostic system capable of detecting the presence of C. difficile in a clinincal sample at the bedside in under 10 minutes | Baillie L(PHRMY), Lees J, Porch A | Cardiff Partnership Fund | 12022 | 01/09/2014 - 31/08/2015 |
| Clean and Green Microwave heating using solid state physics | Cripps, S, Porch A, Lees J | NXP Semiconductors Netherlands B V | 30000 | 01/10/2011 - 30/09/2014 |
Teaching
I became a Fellow of the Higher Education Academy in 2014.
My teaching currently spans all years of Electrical and Electronic Engineering undergraduate and taught postgraduate programmes, as well as various pre-sessional and outreach programmes.
I lead four MSc / MEng modules; Research Project, HF-RF Engineering, Advanced CAD, Fabrication and Test, RF Design and CAD, as well as one first year module; Analogue Communications.
Other current and recent roles include:
Year 4 Tutor – MEng Integrated and Electronic Engineering (current)
Year 1 Tutor – Integrated and Electronic Engineering
MSc Tutor - Wireless and Microwave Communications Engineering (including variants – MRes & 2-year schemes)
MSc Tutor – Communications Technology & Entrepreneurship
MSc Tutor – Compound Semiconductor Electronics
Biography
I began my career in 1998 developing optical and GPS-based positional tracking solutions with QinetiQ, U.K. and became a chartered Engineer in 1999. I obtained my MSc. and PhD. degrees from Cardiff University in 2002 and 2006 respectively and joined the Centre for High Frequency Engineering (CHFE) as a Research Associate in June 2005. I became a Lecturer in 2011 and then in 2016, a Senior Lecturer in Non-Linear Microwave Characterisation. Between 2009 and 2010, I was seconded to Mesuro as a Senior Hardware Engineer.
My current academic roles include Head of Department for Electrical and Electronic Engineering, as well as Year-4 MEng Tutor. Previous roles include Director of Taught Postgraduate programmes for Engineering, Year-1 Tutor for Integrated and Electrical and Electronic Engineering and Director for the Wireless and Microwave Communications Engineering MSc and its variants.
My research focus is developing non-linear microwave measurement and characterisation capabilities, high-performance microwave amplifiers, as well as the study of device non-linearity and linearization using modulated time-domain and envelope domain techniques. My work in this area culminated in the first published GaN Doherty amplifier, and more recent activities consider the development of novel high-power, broad-band time-domain measurement and load-pull techniques as well as dynamic supply modulation techniques in achieving high efficiency and high linearity in microwave power amplifiers. Over recent years I have applied my microwave expertise to medical and other applications, including the design of highly integrated microwave power amplifiers for diagnostic applications, and the generation and use of high power pulsed microwave energy for the detection of clostridium difficile.
I currently supervise / co-supervising over 10 PhD students in Microwave Engineering and related fields. I represented Cardiff University (founder member) in the European EUREKA OperaNET-2 programme driving down power consumption in mobile communications system networks.
Honours and awards
In June 2018 I was awarded the Cardiff University Business Innovation award for work with a local company developing low-power autonomous load-cells.
EEE Teacher of the Year award – EN3082/782 – 2016/17
Supervisions
Current Research Interests
I am interested in supervising PhD students in the areas of
- High efficiency Power Amplifier Design
- mm-wave power amplifier design
- Microwave and mm-wave circuit design techniques
- Medical applications of microwave engineering
- Microwave and mm-wave characterisation
Current Students
| Title | Student | Status | Degree |
|---|---|---|---|
| Device Level Characterisation of Out-phasing Power Amplifiers | Aleksander Bogusz | Current | PhD |
| Integrated Envelope Tracking Power Amplifiers for 5G communications | Alexander Alt | Current | PhD |
| Measurement-Based Non-linear Modelling for Active Devices | Zack Costello | Current | PhD |
| Integrating High-Performance Power Amplifiers with
Miniaturised Wideband Antennas for Highly-Efficient Future Communications Devices | Elango Nagasundaram | Current | PhD |
