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Overview
I am a microwave engineer and have spent over 40 years working in the high frequency electronic industry, both in the UK and 15 years in the USA. After completing my Ph.D at Cambridge I joined the pioneering group at Plessey Research Labs (Caswell) which developed the first commercially available Gallium Arsenide Field Effect (GaAsFET) transistors. After establishing a pilot commercial low noise GaAs amplifier operation I was recruited by Watkins Johnson in California, to join their broadband military ECM amplifier group. During the subsequent 15 years in California I became a recognized authority on microwave power amplifier design, publishing numerous papers through the I.E.E.E and authoring several books on this subject. I returned to the UK in 1996 and acted as an independent consultant in the burgeoning mobile communications sector. I also started my association with the Cardiff University CHFE group, building up a research activity in novel power amplifier techniques. I am a Life Fellow of the I.E.E.E.
Publication
2025
- Cripps, S. 2025. Microwave power sources for industrial, scientific and medical applications. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 383 (2297) 20240069. (10.1098/rsta.2024.0069)
- Jones, J. et al. 2025. A novel microwave applicator for large volume metal powder heating in additive manufacturing. Presented at: APMC 2024 Bali, Indonesia 17-20 November 2024. 2024 IEEE Asia-Pacific Microwave Conference (APMC). IEEE. , pp.1302-1304. (10.1109/apmc60911.2024.10867661)
- Miles, A. et al. 2025. Direct measurement of non-thermal microwave effects on bacterial growth and redox dynamics using a novel high-throughput waveguide applicator. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 383 (2297) 20240073. (10.1098/rsta.2024.0073)
- Powell, A. et al. 2025. Efficient output power configuration in a K-band power amplifier using a split-gate layout. International Journal of Microwave and Wireless Technologies (10.1017/S1759078725101682)
- Silver, K. et al. 2025. A novel miniaturized benchtop EPR spectrometer based on sideband detection using a software-defined radio. Presented at: APMC 2024 Bali, Indonesia 17-20 November 2024. 2024 IEEE Asia-Pacific Microwave Conference (APMC). IEEE. , pp.814-816. (10.1109/apmc60911.2024.10867565)
- Silver, K. et al. 2025. Design considerations for an electron paramagnetic resonance spectrometer for simultaneous epr and neutron diffraction. Presented at: AMPERE 2025 20th Inttetional Conference on Microwave and High Frequency Applications Bari, Italy 15-19 September 2025.
- Urvoy, J. , Quaglia, R. and Cripps, S. C. 2025. Design and simulation of a Doherty-mode OLMBA for enhanced back-off efficiency over an octave bandwidth. Presented at: 2025 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits Torino, Italy 10-11 April 2025. Proceedings of the International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits. IEEE. , pp.1-4. (10.1109/INMMIC64198.2025.10975674)
- Van Den Heuvel, I. et al. 2025. Improved iterative envelope simulation for the efficient prediction of the impact of wideband modulated signals on power amplifier performance. Presented at: 2025 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits Torino, Italy 10-11 April 2025. Proceedings of the International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits. IEEE. , pp.1-4. (10.1109/INMMIC64198.2025.10975660)
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)
- Jones, D. et al. 2024. Novel oscillator for use in near-field microwave microscopy. Presented at: Asia-Pacific Microwave Conference (APMC) 05-08 December 2023. Proceedings 2023 Asia-Pacific Microwave Conference (APMC). IEEE. , pp.829-831. (10.1109/APMC57107.2023.10439775)
- Powell, A. G. et al. 2024. Efficient output power configuration in a K-Band power amplifier using a split-gate layout. Presented at: 19th European Microwave Integrated Circuits Conference (EuMIC) Paris, France 23-24 September 2024. 2024 19th European Microwave Integrated Circuits Conference (EuMIC). IEEE. , pp.275-278. (10.23919/eumic61603.2024.10732591)
- Quaglia, R. , Cripps, S. and Powell, J. 2024. Impact of matching networks on the impedance settling time in high frequency power amplifiers. Presented at: 2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 21-24 January 2024. Proceedings Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 2024. IEEE. , pp.28-30. (10.1109/PAWR59907.2024.10438584)
- Tian, M. et al. 2024. Application of the Cardiff Model for Orthogonal LMBA response prediction. Presented at: 2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 21-24 January 2024. Proceedings Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 2024. IEEE. , pp.17-20. (10.1109/PAWR59907.2024.10438664)
- van den Heuvel, I. et al. 2024. A baseband impedance cancellation technique for wideband multi-transistor amplifiers. IEEE Microwave and Wireless Technology Letters 34 (6), pp.777-780. (10.1109/LMWT.2024.3390594)
2023
- Cripps, S. C. 2023. Swapping tales [Microwave Bytes]. IEEE Microwave Magazine 24 (10), pp.68-72. (10.1109/MMM.2023.3294879)
- Ghozati, S. U. et al. 2023. Load pull-driven behavioral modelling of microwave switches for the design of tunable reflective terminations. Presented at: EuMW 2024: European Microwave Week 2023 19 - 21 September 2023.
- Jones, D. R. et al. 2023. Near-field microwave microscopy for 3D surface assessment of manufactured structures. IEEE Journal of Microwaves 3 (3), pp.962-969. (10.1109/JMW.2023.3261901)
- 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)
- Urvoy, J. et al. 2023. Experimental characterization of a dual-input OLMBA for back-off efficiency improvement. Presented at: 53rd European Microwave Conference (EuMC) Berlin, Germany 19-21 September 2023. Proceedings of 53rd European Microwave Conference. IEEE. , pp.267-270. (10.23919/EuMC58039.2023.10290592)
- Van Den Heuvel, I. et al. 2023. An envelope model for efficient prediction of the impact of wideband signals on power amplifier performance. Presented at: 2023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC) 08-11 November 2023. 2023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC). IEEE. (10.1109/INMMIC57329.2023.10321784)
- Yuan, T. et al. 2023. Output signal re-injection in load modulated balanced amplifiers for RF bandwidth improvement. IEEE Microwave and Wireless Components Letters 33 (10), pp.1458-1461. (10.1109/LMWT.2023.3305812)
2022
- Cripps, S. C. 2022. Moving goalposts [microwave bytes]. IEEE Microwave Magazine 23 (5), pp.20-25. (10.1109/MMM.2022.3148151)
- Cripps, S. C. 2022. Phasing out [microwave bytes]. IEEE Microwave Magazine 23 (8), pp.18-22. (10.1109/MMM.2022.3173068)
- Cripps, S. C. 2022. Still a-masing [microwave bytes]. IEEE Microwave Magazine 24 (1), pp.16-20. (10.1109/MMM.2022.3203943)
- Cripps, S. C. 2022. Tuning up [microwave bytes]. IEEE Microwave Magazine 23 (2), pp.16-54. (10.1109/MMM.2021.3125471)
- Quaglia, R. et al. 2022. Load-modulated balanced amplifier: from first invention to recent development. IEEE Microwave Magazine 23 (12), pp.60-70. (10.1109/MMM.2022.3203940)
- Quaglia, R. et al. 2022. Effect of HEMT output characteristics on the load mismatch resilience in balanced power amplifiers. Presented at: 2022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC) Cardiff, Wales 07-08 April 2022. 2022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE. , pp.1-3. (10.1109/INMMiC54248.2022.9762184)
- Quaglia, R. et al. 2022. Mitigation of load mismatch effects using an orthogonal load modulated balanced amplifier. IEEE Transactions on Microwave Theory and Techniques 70 (6), pp.3329-3341. (10.1109/TMTT.2022.3167414)
2021
- Cripps, S. C. 2021. Canned electromagnetics [microwave bytes]. IEEE Microwave Magazine 22 (5), pp.19-23. (10.1109/MMM.2021.3056972)
- Cripps, S. C. 2021. Clipper classes [microwave bytes]. IEEE Microwave Magazine 22 (12), pp.16-29. (10.1109/MMM.2021.3109499)
- Cripps, S. C. 2021. Coupling factors [microwave bytes]. IEEE Microwave Magazine 22 (3), pp.12-87. (10.1109/MMM.2020.3042578)
- Cripps, S. C. 2021. Cultural interference [microwave bytes]. IEEE Microwave Magazine 22 (1), pp.12-98. (10.1109/MMM.2020.3027941)
- Cripps, S. C. 2021. Iconic circles [microwave bytes]. IEEE Microwave Magazine 22 (7), pp.17-22. (10.1109/MMM.2021.3069605)
- Cripps, S. C. 2021. Vacuous soundings [microwave bytes]. IEEE Microwave Magazine 22 (10), pp.15-20. (10.1109/MMM.2021.3095699)
- Rubio, J. J. M. et al., 2021. 3-20 GHz GaN MMIC Power Amplifier Design Through a COUT Compensation Strategy. IEEE Microwave and Wireless Components Letters 31 (5), pp.469-472. (10.1109/LMWC.2021.3066282)
2020
- Collins, D. J. et al. 2020. The orthogonal LMBA: a novel RFPA architecture with broadband reconfigurability. IEEE Microwave and Wireless Components Letters 30 (9), pp.888-891. (10.1109/LMWC.2020.3010817)
- Cripps, S. C. 2020. Pushing and pulling [microwave bytes]. IEEE Microwave Magazine 21 (10), pp.14-18. (10.1109/MMM.2020.3008306)
- Moreno Rubio, J. et al. 2020. Design of a broadband power amplifier based on power and efficiency contours estimation. IEEE Microwave and Wireless Components Letters 30 (8), pp.772 -774. (10.1109/LMWC.2020.3005833)
2019
- 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)
- Cappello, T. et al., 2019. Supply- and load-modulated balanced amplifier for efficient broadband 5G base stations. IEEE Transactions on Microwave Theory and Techniques 67 (7), pp.3122-3133. (10.1109/TMTT.2019.2915082)
- Parker, N. et al. 2019. A novel VHF heating system to aid selective laser melting. Presented at: 2019 IEEE MTT-S International Microwave Symposium, IMS 2019 Boston, USA 2 -7 June 2019. , pp.-.
- Quaglia, R. et al. 2019. A 1.8-3.2 GHz Doherty Power Amplifier in quasi-MMIC Technology. IEEE Microwave and Wireless Components Letters 29 (5), pp.345-347. (10.1109/LMWC.2019.2904883)
2018
- 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.
- Collins, D. et al. 2018. Experimental characterization of a load modulated balanced amplifier with simplified input power splitter. Presented at: APMC 2018 Kyoto, Japan 6-9 Nov 2018.
- Powell, J. R. et al., 2018. A power reconfigurable high-efficiency $X$ -band power amplifier MMIC using the load modulated balanced amplifier technique. IEEE Microwave and Wireless Components Letters 28 (6), pp.527-529. (10.1109/LMWC.2018.2824560)
- Quaglia, R. and Cripps, S. 2018. A load modulated balanced amplifier for telecom applications. IEEE Transactions on Microwave Theory and Techniques 66 (3), pp.1328-1338. (10.1109/TMTT.2017.2766066)
2017
- Al-Ziayree, A. M. L. , Perks, R. M. and Cripps, S. C. 2017. A 25 µm spatial resolution broadband microwave voltage probe. Presented at: 2016 International Conference for Students on Applied Engineering (ICSAE) Newcastle upon Tyne, UK 20-21 October 2016. International Conference for Students on Applied Engineering (ICSAE). IEEE. , pp.7-11. (10.1109/ICSAE.2016.7810152)
- Cripps, S. C. 2017. Great Equations? [Microwave Bytes]. IEEE Microwave Magazine 18 (2), pp.24-27. (10.1109/MMM.2016.2635924)
- Quaglia, R. , Bell, J. J. and Cripps, S. 2017. New general formulation and experimental verification of harmonic clipping contours in high-frequency power devices. IEEE Transactions on Microwave Theory and Techniques 65 (10), pp.3903-3909. (10.1109/TMTT.2017.2687900)
- Quaglia, R. and Cripps, S. C. 2017. Harmonic clipping contours: numerical computation and extension to higher harmonics. Presented at: European Microwave Conference London, UK 3-7 Oct. 2016. Microwave Conference (EuMC), 2016 46th European. IEEE. , pp.405-408. (10.1109/EuMC.2016.7824365)
- Quaglia, R. , Shepphard, D. J. and Cripps, S. 2017. A reappraisal of optimum output matching conditions in microwave power transistors. IEEE Transactions on Microwave Theory and Techniques 65 (3), pp.838-845. (10.1109/TMTT.2016.2627557)
- Shepphard, D. J. , Powell, J. and Cripps, S. C. 2017. A broadband reconfigurable load modulated balanced amplifier (LMBA). Presented at: IEEE MTT-S International Microwave Symposium (IMS) Honololu, HI, USA 4-9 June 2017. 2017 IEEE MTT-S International Microwave Symposium (IMS). IEEE. , pp.943-945. (10.1109/MWSYM.2017.8058743)
- Smith, R. M. H. and Cripps, S. C. 2017. Broadband push-pull power amplifier design at microwave frequencies. Presented at: 2016 46th European Microwave Conference (EuMC) 4-6 October 2016. 2016 46th European Microwave Conference (EuMC). IEEE. , pp.1353-1356. (10.1109/EuMC.2016.7824603)
2016
- Al-Ziayree, A. M. L. , Cripps, S. C. and Perks, R. M. 2016. A novel microwave non contact current probe with high spatial resolution. Presented at: 2016 IEEE MTT-S International Microwave Symposium (IMS) San Francisco, CA, USA 22-27 May 2016. 2016 IEEE MTT-S International Microwave Symposium (IMS). IEEE. , pp.1-3. (10.1109/MWSYM.2016.7540265)
- Loescher, D. , Tasker, P. and Cripps, S. 2016. Using waveform engineering to understand the impact of harmonic terminations during 5:1 VSWR stress tests. Presented at: Power Amplifiers for Wireless and Radio Applications (PAWR), 2016 IEEE Topical Conference on Austin, TX, USA 24-27 Jan. 2016. 2016 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR). IEEE. , pp.49-52. (10.1109/PAWR.2016.7440161)
- Powell, J. R. , Shepphard, D. and Cripps, S. C. 2016. High efficiency GaN 2.5 to 9 GHz power amplifiers realized in multilayer LCP hybrid technology. IEEE Microwave and Wireless Components Letters 26 (6), pp.440-442. (10.1109/LMWC.2016.2559502)
- Shepphard, D. , Powell, J. and Cripps, S. C. 2016. An efficient broadband reconfigurable power amplifier using active load modulation. IEEE Microwave and Wireless Components Letters 26 (6), pp.443-445. (10.1109/LMWC.2016.2559503)
- 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)
2015
- Cripps, S. C. 2015. Behavioral swing [microwave bytes]. IEEE Microwave Magazine 16 (10), pp.20-25. (10.1109/MMM.2015.2465714)
- Cripps, S. C. 2015. Intermodulation squared response [Microwave bytes]. IEEE Microwave Magazine 16 (5), pp.102-106. (10.1109/MMM.2015.2410617)
- Cripps, S. C. 2015. The evolution of the push-pull RFPA. Presented at: 2015 IEEE MTT-S International Microwave Symposium Phoenix, AZ, USA 17-22 May 2015. 2015 IEEE MTT-S International Microwave Symposium. IEEE. , pp.1-4.
- Dehghan, N. and Cripps, S. C. 2015. A novel in-situ calibration technique for a high resolution E-Field probe. Presented at: 2015 IEEE MTT-S International Microwave Symposium Phoenix, AZ, USA 17-22 May 2015. 2015 IEEE MTT-S International Microwave Symposium. IEEE. , pp.1-3.
2014
- Canning, T. , Powell, J. R. and Cripps, S. C. 2014. Optimal design of broadband microwave baluns using single-layer planar circuit technology. IEEE Transactions on Microwave Theory and Techniques 62 (5), pp.1183-1191. (10.1109/TMTT.2014.2311417)
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2014. Continuous mode power amplifier design using harmonic clipping contours: theory and practice. IEEE Transactions on Microwave Theory and Techniques 62 (1), pp.100-110. (10.1109/TMTT.2013.2292675)
2013
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2013. Load Pull verification of a novel Class B/J design tool: Second harmonic clipping contours. Presented at: 81 st ARFTG Microwave Measurement Conference Seattle, WA, USA 7 June 2013. Microwave Measurement Conference (ARFTG), 2013 81st ARFTG. IEEE. , pp.1-3. (10.1109/ARFTG.2013.6579040)
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2013. Waveform evidence of gate harmonic short circuit benefits for high efficiency x-band power amplifiers. IEEE Microwave and Wireless Components Letters 23 (8), pp.439-441. (10.1109/LMWC.2013.2272317)
- Haynes, M. , Tasker, P. J. and Cripps, S. C. 2013. High efficiency PA design strategy at X-Band. Presented at: 2013 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS) Monterey, CA, USA 13-16 October 2013. Compound Semiconductor Integrated Circuit Symposium (CSICS), 2013 IEEE. IEEE. , pp.1-4. (10.1109/CSICS.2013.6659232)
- 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
- 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)
- 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
- 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)
- Powell, J. R. et al., 2011. GaAs X-band high efficiency (65%) broadband (30%) amplifier MMIC based on the Class B to Class J continuum. 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.355. (10.1109/MWSYM.2011.5973350)
- 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.
- 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)
- 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.
- Cripps, S. C. and Porch, A. 2010. An active, non-intrusive, high resolution microwave field probe with applications in high power RF device and circuit design. Presented at: 2010 IEEE 11th Annual Wireless and Microwave Technology Conference (WAMICON 2010) Melbourne Beach, USAVol. 546185.
- 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)
- Mashad Nemati, H. et al. 2010. Evaluation of a GaN HEMT transistor for load- and supply-modulation applications using intrinsic waveform measurements. Presented at: IEEE MTT 2010 International Microwave Symposium Anaheim, CA, USA 23-28 May 2010. 2010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). Piscataway, NJ: IEEE. , pp.509-512. (10.1109/MWSYM.2010.5517696)
2009
- 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)
- 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
- Cripps, S. 2008. Trapwave Inc. [Microwave Bytes]. IEEE Microwave Magazine 9 (4), pp.46-51. 10103186. (10.1109/MMM.2008.924789)
- 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)
Articles
- 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)
- Canning, T. , Powell, J. R. and Cripps, S. C. 2014. Optimal design of broadband microwave baluns using single-layer planar circuit technology. IEEE Transactions on Microwave Theory and Techniques 62 (5), pp.1183-1191. (10.1109/TMTT.2014.2311417)
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2013. Waveform evidence of gate harmonic short circuit benefits for high efficiency x-band power amplifiers. IEEE Microwave and Wireless Components Letters 23 (8), pp.439-441. (10.1109/LMWC.2013.2272317)
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2014. Continuous mode power amplifier design using harmonic clipping contours: theory and practice. IEEE Transactions on Microwave Theory and Techniques 62 (1), pp.100-110. (10.1109/TMTT.2013.2292675)
- Cappello, T. et al., 2019. Supply- and load-modulated balanced amplifier for efficient broadband 5G base stations. IEEE Transactions on Microwave Theory and Techniques 67 (7), pp.3122-3133. (10.1109/TMTT.2019.2915082)
- 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)
- Collins, D. J. et al. 2020. The orthogonal LMBA: a novel RFPA architecture with broadband reconfigurability. IEEE Microwave and Wireless Components Letters 30 (9), pp.888-891. (10.1109/LMWC.2020.3010817)
- Cripps, S. C. 2015. Behavioral swing [microwave bytes]. IEEE Microwave Magazine 16 (10), pp.20-25. (10.1109/MMM.2015.2465714)
- Cripps, S. C. 2015. Intermodulation squared response [Microwave bytes]. IEEE Microwave Magazine 16 (5), pp.102-106. (10.1109/MMM.2015.2410617)
- 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)
- Cripps, S. 2025. Microwave power sources for industrial, scientific and medical applications. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 383 (2297) 20240069. (10.1098/rsta.2024.0069)
- Cripps, S. 2008. Trapwave Inc. [Microwave Bytes]. IEEE Microwave Magazine 9 (4), pp.46-51. 10103186. (10.1109/MMM.2008.924789)
- Cripps, S. C. 2021. Canned electromagnetics [microwave bytes]. IEEE Microwave Magazine 22 (5), pp.19-23. (10.1109/MMM.2021.3056972)
- Cripps, S. C. 2021. Clipper classes [microwave bytes]. IEEE Microwave Magazine 22 (12), pp.16-29. (10.1109/MMM.2021.3109499)
- Cripps, S. C. 2021. Coupling factors [microwave bytes]. IEEE Microwave Magazine 22 (3), pp.12-87. (10.1109/MMM.2020.3042578)
- Cripps, S. C. 2021. Cultural interference [microwave bytes]. IEEE Microwave Magazine 22 (1), pp.12-98. (10.1109/MMM.2020.3027941)
- Cripps, S. C. 2017. Great Equations? [Microwave Bytes]. IEEE Microwave Magazine 18 (2), pp.24-27. (10.1109/MMM.2016.2635924)
- Cripps, S. C. 2021. Iconic circles [microwave bytes]. IEEE Microwave Magazine 22 (7), pp.17-22. (10.1109/MMM.2021.3069605)
- Cripps, S. C. 2022. Moving goalposts [microwave bytes]. IEEE Microwave Magazine 23 (5), pp.20-25. (10.1109/MMM.2022.3148151)
- Cripps, S. C. 2022. Phasing out [microwave bytes]. IEEE Microwave Magazine 23 (8), pp.18-22. (10.1109/MMM.2022.3173068)
- Cripps, S. C. 2020. Pushing and pulling [microwave bytes]. IEEE Microwave Magazine 21 (10), pp.14-18. (10.1109/MMM.2020.3008306)
- Cripps, S. C. 2022. Still a-masing [microwave bytes]. IEEE Microwave Magazine 24 (1), pp.16-20. (10.1109/MMM.2022.3203943)
- Cripps, S. C. 2023. Swapping tales [Microwave Bytes]. IEEE Microwave Magazine 24 (10), pp.68-72. (10.1109/MMM.2023.3294879)
- Cripps, S. C. 2022. Tuning up [microwave bytes]. IEEE Microwave Magazine 23 (2), pp.16-54. (10.1109/MMM.2021.3125471)
- Cripps, S. C. 2021. Vacuous soundings [microwave bytes]. IEEE Microwave Magazine 22 (10), pp.15-20. (10.1109/MMM.2021.3095699)
- Jones, D. R. et al. 2023. Near-field microwave microscopy for 3D surface assessment of manufactured structures. IEEE Journal of Microwaves 3 (3), pp.962-969. (10.1109/JMW.2023.3261901)
- Miles, A. et al. 2025. Direct measurement of non-thermal microwave effects on bacterial growth and redox dynamics using a novel high-throughput waveguide applicator. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 383 (2297) 20240073. (10.1098/rsta.2024.0073)
- Moreno Rubio, J. et al. 2020. Design of a broadband power amplifier based on power and efficiency contours estimation. IEEE Microwave and Wireless Components Letters 30 (8), pp.772 -774. (10.1109/LMWC.2020.3005833)
- Powell, A. et al. 2025. Efficient output power configuration in a K-band power amplifier using a split-gate layout. International Journal of Microwave and Wireless Technologies (10.1017/S1759078725101682)
- Powell, J. R. et al., 2018. A power reconfigurable high-efficiency $X$ -band power amplifier MMIC using the load modulated balanced amplifier technique. IEEE Microwave and Wireless Components Letters 28 (6), pp.527-529. (10.1109/LMWC.2018.2824560)
- Powell, J. R. , Shepphard, D. and Cripps, S. C. 2016. High efficiency GaN 2.5 to 9 GHz power amplifiers realized in multilayer LCP hybrid technology. IEEE Microwave and Wireless Components Letters 26 (6), pp.440-442. (10.1109/LMWC.2016.2559502)
- Quaglia, R. , Bell, J. J. and Cripps, S. 2017. New general formulation and experimental verification of harmonic clipping contours in high-frequency power devices. IEEE Transactions on Microwave Theory and Techniques 65 (10), pp.3903-3909. (10.1109/TMTT.2017.2687900)
- Quaglia, R. and Cripps, S. 2018. A load modulated balanced amplifier for telecom applications. IEEE Transactions on Microwave Theory and Techniques 66 (3), pp.1328-1338. (10.1109/TMTT.2017.2766066)
- Quaglia, R. et al. 2019. A 1.8-3.2 GHz Doherty Power Amplifier in quasi-MMIC Technology. IEEE Microwave and Wireless Components Letters 29 (5), pp.345-347. (10.1109/LMWC.2019.2904883)
- Quaglia, R. et al. 2022. Load-modulated balanced amplifier: from first invention to recent development. IEEE Microwave Magazine 23 (12), pp.60-70. (10.1109/MMM.2022.3203940)
- Quaglia, R. et al. 2022. Mitigation of load mismatch effects using an orthogonal load modulated balanced amplifier. IEEE Transactions on Microwave Theory and Techniques 70 (6), pp.3329-3341. (10.1109/TMTT.2022.3167414)
- Quaglia, R. , Shepphard, D. J. and Cripps, S. 2017. A reappraisal of optimum output matching conditions in microwave power transistors. IEEE Transactions on Microwave Theory and Techniques 65 (3), pp.838-845. (10.1109/TMTT.2016.2627557)
- Rubio, J. J. M. et al., 2021. 3-20 GHz GaN MMIC Power Amplifier Design Through a COUT Compensation Strategy. IEEE Microwave and Wireless Components Letters 31 (5), pp.469-472. (10.1109/LMWC.2021.3066282)
- Shepphard, D. , Powell, J. and Cripps, S. C. 2016. An efficient broadband reconfigurable power amplifier using active load modulation. IEEE Microwave and Wireless Components Letters 26 (6), pp.443-445. (10.1109/LMWC.2016.2559503)
- 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)
- van den Heuvel, I. et al. 2024. A baseband impedance cancellation technique for wideband multi-transistor amplifiers. IEEE Microwave and Wireless Technology Letters 34 (6), pp.777-780. (10.1109/LMWT.2024.3390594)
- 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)
- Yuan, T. et al. 2023. Output signal re-injection in load modulated balanced amplifiers for RF bandwidth improvement. IEEE Microwave and Wireless Components Letters 33 (10), pp.1458-1461. (10.1109/LMWT.2023.3305812)
- 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)
Conferences
- 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.
- Al-Ziayree, A. M. L. , Cripps, S. C. and Perks, R. M. 2016. A novel microwave non contact current probe with high spatial resolution. Presented at: 2016 IEEE MTT-S International Microwave Symposium (IMS) San Francisco, CA, USA 22-27 May 2016. 2016 IEEE MTT-S International Microwave Symposium (IMS). IEEE. , pp.1-3. (10.1109/MWSYM.2016.7540265)
- Al-Ziayree, A. M. L. , Perks, R. M. and Cripps, S. C. 2017. A 25 µm spatial resolution broadband microwave voltage probe. Presented at: 2016 International Conference for Students on Applied Engineering (ICSAE) Newcastle upon Tyne, UK 20-21 October 2016. International Conference for Students on Applied Engineering (ICSAE). IEEE. , pp.7-11. (10.1109/ICSAE.2016.7810152)
- 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.
- 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)
- 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)
- 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.
- 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. 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)
- 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)
- Canning, T. A. J. , Tasker, P. J. and Cripps, S. C. 2013. Load Pull verification of a novel Class B/J design tool: Second harmonic clipping contours. Presented at: 81 st ARFTG Microwave Measurement Conference Seattle, WA, USA 7 June 2013. Microwave Measurement Conference (ARFTG), 2013 81st ARFTG. IEEE. , pp.1-3. (10.1109/ARFTG.2013.6579040)
- 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.
- 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. 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. 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)
- Collins, D. et al. 2018. Experimental characterization of a load modulated balanced amplifier with simplified input power splitter. Presented at: APMC 2018 Kyoto, Japan 6-9 Nov 2018.
- Cripps, S. C. 2015. The evolution of the push-pull RFPA. Presented at: 2015 IEEE MTT-S International Microwave Symposium Phoenix, AZ, USA 17-22 May 2015. 2015 IEEE MTT-S International Microwave Symposium. IEEE. , pp.1-4.
- Cripps, S. C. and Porch, A. 2010. An active, non-intrusive, high resolution microwave field probe with applications in high power RF device and circuit design. Presented at: 2010 IEEE 11th Annual Wireless and Microwave Technology Conference (WAMICON 2010) Melbourne Beach, USAVol. 546185.
- Dehghan, N. and Cripps, S. C. 2015. A novel in-situ calibration technique for a high resolution E-Field probe. Presented at: 2015 IEEE MTT-S International Microwave Symposium Phoenix, AZ, USA 17-22 May 2015. 2015 IEEE MTT-S International Microwave Symposium. IEEE. , pp.1-3.
- 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)
- 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)
- Ghozati, S. U. et al. 2023. Load pull-driven behavioral modelling of microwave switches for the design of tunable reflective terminations. Presented at: EuMW 2024: European Microwave Week 2023 19 - 21 September 2023.
- Haynes, M. , Tasker, P. J. and Cripps, S. C. 2013. High efficiency PA design strategy at X-Band. Presented at: 2013 IEEE Compound Semiconductor Integrated Circuit Symposium (CSICS) Monterey, CA, USA 13-16 October 2013. Compound Semiconductor Integrated Circuit Symposium (CSICS), 2013 IEEE. IEEE. , pp.1-4. (10.1109/CSICS.2013.6659232)
- Jones, D. et al. 2024. Novel oscillator for use in near-field microwave microscopy. Presented at: Asia-Pacific Microwave Conference (APMC) 05-08 December 2023. Proceedings 2023 Asia-Pacific Microwave Conference (APMC). IEEE. , pp.829-831. (10.1109/APMC57107.2023.10439775)
- Jones, J. et al. 2025. A novel microwave applicator for large volume metal powder heating in additive manufacturing. Presented at: APMC 2024 Bali, Indonesia 17-20 November 2024. 2024 IEEE Asia-Pacific Microwave Conference (APMC). IEEE. , pp.1302-1304. (10.1109/apmc60911.2024.10867661)
- 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)
- 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)
- Loescher, D. , Tasker, P. and Cripps, S. 2016. Using waveform engineering to understand the impact of harmonic terminations during 5:1 VSWR stress tests. Presented at: Power Amplifiers for Wireless and Radio Applications (PAWR), 2016 IEEE Topical Conference on Austin, TX, USA 24-27 Jan. 2016. 2016 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR). IEEE. , pp.49-52. (10.1109/PAWR.2016.7440161)
- Mashad Nemati, H. et al. 2010. Evaluation of a GaN HEMT transistor for load- and supply-modulation applications using intrinsic waveform measurements. Presented at: IEEE MTT 2010 International Microwave Symposium Anaheim, CA, USA 23-28 May 2010. 2010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). Piscataway, NJ: IEEE. , pp.509-512. (10.1109/MWSYM.2010.5517696)
- Parker, N. et al. 2019. A novel VHF heating system to aid selective laser melting. Presented at: 2019 IEEE MTT-S International Microwave Symposium, IMS 2019 Boston, USA 2 -7 June 2019. , pp.-.
- Powell, A. G. et al. 2024. Efficient output power configuration in a K-Band power amplifier using a split-gate layout. Presented at: 19th European Microwave Integrated Circuits Conference (EuMIC) Paris, France 23-24 September 2024. 2024 19th European Microwave Integrated Circuits Conference (EuMIC). IEEE. , pp.275-278. (10.23919/eumic61603.2024.10732591)
- Powell, J. R. et al., 2011. GaAs X-band high efficiency (65%) broadband (30%) amplifier MMIC based on the Class B to Class J continuum. 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.355. (10.1109/MWSYM.2011.5973350)
- Quaglia, R. and Cripps, S. C. 2017. Harmonic clipping contours: numerical computation and extension to higher harmonics. Presented at: European Microwave Conference London, UK 3-7 Oct. 2016. Microwave Conference (EuMC), 2016 46th European. IEEE. , pp.405-408. (10.1109/EuMC.2016.7824365)
- Quaglia, R. , Cripps, S. and Powell, J. 2024. Impact of matching networks on the impedance settling time in high frequency power amplifiers. Presented at: 2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 21-24 January 2024. Proceedings Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 2024. IEEE. , pp.28-30. (10.1109/PAWR59907.2024.10438584)
- Quaglia, R. et al. 2022. Effect of HEMT output characteristics on the load mismatch resilience in balanced power amplifiers. Presented at: 2022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC) Cardiff, Wales 07-08 April 2022. 2022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE. , pp.1-3. (10.1109/INMMiC54248.2022.9762184)
- Shepphard, D. J. , Powell, J. and Cripps, S. C. 2017. A broadband reconfigurable load modulated balanced amplifier (LMBA). Presented at: IEEE MTT-S International Microwave Symposium (IMS) Honololu, HI, USA 4-9 June 2017. 2017 IEEE MTT-S International Microwave Symposium (IMS). IEEE. , pp.943-945. (10.1109/MWSYM.2017.8058743)
- Silver, K. et al. 2025. A novel miniaturized benchtop EPR spectrometer based on sideband detection using a software-defined radio. Presented at: APMC 2024 Bali, Indonesia 17-20 November 2024. 2024 IEEE Asia-Pacific Microwave Conference (APMC). IEEE. , pp.814-816. (10.1109/apmc60911.2024.10867565)
- Silver, K. et al. 2025. Design considerations for an electron paramagnetic resonance spectrometer for simultaneous epr and neutron diffraction. Presented at: AMPERE 2025 20th Inttetional Conference on Microwave and High Frequency Applications Bari, Italy 15-19 September 2025.
- 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. H. and Cripps, S. C. 2017. Broadband push-pull power amplifier design at microwave frequencies. Presented at: 2016 46th European Microwave Conference (EuMC) 4-6 October 2016. 2016 46th European Microwave Conference (EuMC). IEEE. , pp.1353-1356. (10.1109/EuMC.2016.7824603)
- 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)
- Tian, M. et al. 2024. Application of the Cardiff Model for Orthogonal LMBA response prediction. Presented at: 2024 IEEE Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 21-24 January 2024. Proceedings Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 2024. IEEE. , pp.17-20. (10.1109/PAWR59907.2024.10438664)
- Urvoy, J. , Quaglia, R. and Cripps, S. C. 2025. Design and simulation of a Doherty-mode OLMBA for enhanced back-off efficiency over an octave bandwidth. Presented at: 2025 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits Torino, Italy 10-11 April 2025. Proceedings of the International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits. IEEE. , pp.1-4. (10.1109/INMMIC64198.2025.10975674)
- Urvoy, J. et al. 2023. Experimental characterization of a dual-input OLMBA for back-off efficiency improvement. Presented at: 53rd European Microwave Conference (EuMC) Berlin, Germany 19-21 September 2023. Proceedings of 53rd European Microwave Conference. IEEE. , pp.267-270. (10.23919/EuMC58039.2023.10290592)
- Van Den Heuvel, I. et al. 2023. An envelope model for efficient prediction of the impact of wideband signals on power amplifier performance. Presented at: 2023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC) 08-11 November 2023. 2023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC). IEEE. (10.1109/INMMIC57329.2023.10321784)
- Van Den Heuvel, I. et al. 2025. Improved iterative envelope simulation for the efficient prediction of the impact of wideband modulated signals on power amplifier performance. Presented at: 2025 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits Torino, Italy 10-11 April 2025. Proceedings of the International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits. IEEE. , pp.1-4. (10.1109/INMMIC64198.2025.10975660)
- 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)
- 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)
Research
Contracts
| Title | People | Sponsor | Value | Duration |
|---|---|---|---|---|
| Development of robust broadband Power amplifiers based on high voltage HBT's | Tasker P, Cripps S | TriQuint WJ Inc | 27500 | 01/10/2012 - 30/09/2015 |
| 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 |
| Wide bandwidth power-switchable high efficiency amplifiers | Cripps S | Selex ES | 88650 | 15/10/2014 - 31/12/2015 |
| Power amplifier design for wideband communications (PADWIC) | Cripps S | EC Horizon2020 | 146764 | 01/09/2015 - 31/08/2017 |
| Wide band high efficiency power amplifier study and demonstration | Cripps S | Selex ES Ltd | 40000 | 16/09/2013 - 30/04/2014 |
| RF Push-pull broadband power amplifiers | Cripps S, Powell J | SELEX ES LTD | 24949 | 11/01/2013 - 12/07/2013 |
| Characterization, analysis and recommendations for drain efficiency of the VHV8 platform above 1GHz | Cripps S, Tasker P | Freescale Semiconductor | 33710 | 23/04/2014 - 22/10/2014 |
| 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 |
Supervised Students
| Title | Student | Status | Degree |
|---|---|---|---|
| Device level characterisation of out-phasing amplifiers | BOGUSZ Aleksander | Current | PhD |
| Solid-State Microwave heating For Biomedical Applications | IMTIAZ Azeem | Graduate | PhD |
| Re-configure high efficiency power amplifiers. | SHEPPHARD Daniel John | Current | PhD |
| DEVELOPMENT OF ROBUST BROADBAND POWER AMPLIFIERS BASED ON HIGH VOLTAGE HBTS. | LOESCHER David John | Current | PhD |
| INTEGRATING HIGH-PERFORMANCE POWER AMPLIFIERS WITH MINIATURIZED WIDEBAND ANTENNAS FOR HIGHLY-EFFICIENT FUTURE COMMUNICATION DEVICES. | NAGASUNDARAM Elango | Current | PhD |
| Power amplifier design for microwave heating applications | CHAUDHRY Kauser | Current | PhD |
| High Resolution Electric Field Probes With Applications In High Efficiency RF Power Amplifier Design | DEHGHAN Nelo | Graduate | PhD |
| Broadband Microwave Push-Pull Power Amplifiers | SMITH Robert | Graduate | PhD |
| DOHERTY AMPLIFIER WITH AID OF AD-HOC OPTIMIZATION FOR SDR APPLICATIONS. | KAMARUDIN Syalwani Binti | Current | PhD |
| Continuous Mode High Efficiency Power Amplifier Design For X Band | CANNING Timothy | Graduate | PhD |
| The Auxiliary Envelope Tracking RF Power Amplifiers | YUSOFF Zubaida | Graduate | PhD |
Biography
Prof. Steve C. Cripps
Born: Liverpool, England; 1950
Education:
1961-67 Liverpool Institute High School
1968-71 Cambridge University (JesusCollege); B.A. (Honours, 1st Class) 1971
M.A. (Cambridge University, 1973)
1971-74 Cambridge University (Engineering Dept.) ; Ph.D. 1975
(Thesis Title "Trappatt Oscillators and Applications")
Professional Affiliation:
Fellow, I.E.E.E. (Life Fellow 2015)
Chairman, I.E.E.E Microwave Theory and Techniques (MTT) Society, Santa
ClaraValley Chapter. (1993-4)
Member, UK ADCOM IEEE MTT/LEOS Chapter
Member, IEEE MTT Technical Co-ordination Committee (TCC)
Member, IEEE MTT Technical Program Committee
Member, IEEE MTT Publications Committee
Vice Chair (past) , IEEE MTT TCC Section 5 (High Power Amplifiers)
(Note: MTT-TPC committee reviews and selects papers for the International Microwave Symposium, and the IEEE Transactions on Microwave Theory and Techniques. MTT-TCC sets policies and priorities for research activities and publications in the microwave and RF field).
Awards:
2008 recipient of the prestigious IEEE-MTT Microwave Applications Award, for “Contributions to the theory and design of broadband microwave power amplifiers”.
2016 recipient of IEEE-MTT Microwave prize for best paper in MTT Transactions (2014-15).
2018 recipient of IEEE MTT Itoh Award for most influential paper in Microwave and Wirless Components Letters (2017-18).
Work Experience:
2010-present Distinguished Research Professor, Cardiff University
1990 (April)- Formed Hywave Associates, an RF and Microwave Consulting Company. Clients to date include:
Freescale, RF Semiconductor Division (Tempe, Az., USA)
Zinwave (Cambrudge, UK, radio over fiber amplifiers)
Lucent-Alcatel (Swindon, UK, High Power PAs)
BesserAssociates (Technical Training Courses)
CEI Europe (Technical Training Courses)
Litton Applied Technology Division (ECM Microwave Component and Subsystems)
Wavetek Microwave (Microwave Instruments)
Matcom (GaAsFET Applications Engineering)
Palm Technology (Fiber Optical Communications)
Akon (Broadband Detector Log Amplifiers (DLVAs)
New Focus (Optical Instrumentation)
Pacific Monolithics (GaAs MMICs and subsystems)
ADX Microsys (Wireless Communications Systems)
Microwave Technology (Microwave devices and subsystems)
Spectrian (Cellular Base Station Power Amps)
TriquintSemiconductor (GaAs MMIC Power Amplifiers)
Nokia Telecommunications (MCPA Linearisation)
Filtronic (Shipley, UK, High Power PAs and linearization)
NXP Semiconductors (Nijmegen, Netherlands, High power RF semiconductors)
Scintera (Santa Clara, USA, PA linearization RFICs)
1985-1990 - Celeritek, San Jose (Founder, Engineering Manager).
Managed all design Engineering activities in the Company including planning, recruitment, quotations, documentation system, CAD and Engineering Lab facilities. Also worked as individual engineering contributor in several major product areas:
* Broadband MIC power amplifiers
* Low noise amplifiers
* Ultra wideband amplifiers (2-20 GHz)
* Millimeter wave amplifiers (18-40 Ghz)
* Miniaturized MIC packaging
* Advanced thin film technology
* MMIC products (amplifiers, switches, attenuators)
1984-85 - Narda West, (Loral Corp.),San Jose
Manager, Active Component Engineering.Headed the Engineering Group for microwave amplifier product line (13 Engineers, Technicians).
New product areas developed during this period included RF logarithmic amplifiers and digitally programmable AGC amplifiers over 2 to 18 GHz frequency bands. Successful procedures and test methods were implemented for shipping production quantities of frequency memory loop amplifiers (FML).
1979-84 Watkins Johnson (Palo Alto, and Windsor, England)
Head, Power Amplifiers (1982-84). Headed a group responsible for the design and production of medium power solid state amplifiers.Personally responsible for the design of the industry's first 2-8 GHz 1 Watt solid state amplifier. To achieve this, a new theoretical approach to the design and modelling of high power GaAsFETs was developed and published (see publications, 1983). This technique is still widely used today.
Prior to transferring to the Solid State Division in 1981, was a Group Leader at the England facility of Watkins Johnson. Developed a range of active and passive components in the UHF and microwave range to complement an antenna distribution product line.
1974-79 - Plessey Research Ltd.,Towcester, England.
Group Leader, GaAsFET hybrid applications group (1977-79). Headed a group (6 Engineers) developing a range of products using internally manufactured GaAs FET devices. These included low noise amplifiers, mixers, and oscillators.
Patents:
"A MicrostripBalun Having Improved Bandwidth"
(Issued April 1988)
"Multiple FET Devices Having Direct Coupled Stages for Improved Microwave Operation" (Issued June 1991)
"Method and Means for the Measurement of Active Device Channel Temperature in Microwave Hybrids and MMICs"
(Issued July 1991)
"A Microwave Detector Having Improved Linearity" (Issued 1993)
“High Efficiency RF Power Amplifier” (Issued July 1994)
“A reconfigurable Microwave Amplifier” (sponsored by Selex, pending)