![Steve Cripps](https://profiles-cardiff.imgix.net/attachments/3849?w=200&h=200&auto=format&crop=faces&fit=crop&q=90")
Professor Steve Cripps
Distinguished Research Professor
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
2024
- Jones, D., Cripps, S., Choi, H., Perks, R., Porch, A. and Brown, P. 2024. Novel oscillator for use in near-field microwave microscopy. Presented at: Asia-Pacific Microwave Conference (APMC), 05-08 December 2023Proceedings 2023 Asia-Pacific Microwave Conference (APMC). IEEE pp. 829-831., (10.1109/APMC57107.2023.10439775)
- 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 2024Proceedings 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., Urvoy, J., Powell, J., Bell, J. J., Cripps, S. C., Tasker, P. and Quaglia, R. 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 2024Proceedings Topical Conference on RF/Microwave Power Amplifiers for Radio and Wireless Applications (PAWR) 2024. IEEE pp. 17-20., (10.1109/PAWR59907.2024.10438664)
2023
- Van Den Heuvel, I., Quaglia, R., Cripps, S. C. and Tasker, P. J. 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 20232023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC). IEEE, (10.1109/INMMIC57329.2023.10321784)
- Yuan, T., Quaglia, R., Chaudhry, K., Azad, E., Powell, J. R. and Cripps, S. C. 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)
- Urvoy, J., Quaglia, R., Powell, J. R. and Cripps, S. C. 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 2023Proceedings of 53rd European Microwave Conference. IEEE pp. 267-270., (10.23919/EuMC58039.2023.10290592)
- Cripps, S. C. 2023. Swapping tales [Microwave Bytes]. IEEE Microwave Magazine 24(10), pp. 68-72. (10.1109/MMM.2023.3294879)
- Jones, D. R., Brown, P., McFarland, G., Perks, R., Choi, H., Cripps, S. and Porch, A. 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., Bogusz, A., Lees, J., Quaglia, R., Cripps, S., Montoro, G. and Gilabert, P. L. 2023. Performance modeling and shaping function extraction for dual-input load modulated power amplifiers. Presented at: 2023 IEEE/MTT-S International Microwave Symposium - IMS 2023, San Diego, USA, 11-16 June 2023Proceedings of the 2023 IEEE/MTT-S International Microwave Symposium (IMS). IEEE pp. 203-206., (10.1109/IMS37964.2023.10188039)
- Ghozati, S. U., Quaglia, R., Azad, E., Powell, J., Tasker, P. and Cripps, S. 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.
2022
- Cripps, S. C. 2022. Still a-masing [microwave bytes]. IEEE Microwave Magazine 24(1), pp. 16-20. (10.1109/MMM.2022.3203943)
- Quaglia, R., Pang, J., Cripps, S. C. and Zhu, A. 2022. Load-modulated balanced amplifier: from first invention to recent development. IEEE Microwave Magazine 23(12), pp. 60-70. (10.1109/MMM.2022.3203940)
- Cripps, S. C. 2022. Phasing out [microwave bytes]. IEEE Microwave Magazine 23(8), pp. 18-22. (10.1109/MMM.2022.3173068)
- Quaglia, R., Powell, J. R., Chaudhry, K. and Cripps, S. C. 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)
- Cripps, S. C. 2022. Moving goalposts [microwave bytes]. IEEE Microwave Magazine 23(5), pp. 20-25. (10.1109/MMM.2022.3148151)
- Quaglia, R., Powell, J., Chaudhry, K. and Cripps, S. 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 20222022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC54248.2022.9762184)
- Cripps, S. C. 2022. Tuning up [microwave bytes]. IEEE Microwave Magazine 23(2), pp. 16-54. (10.1109/MMM.2021.3125471)
2021
- 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. Vacuous soundings [microwave bytes]. IEEE Microwave Magazine 22(10), pp. 15-20. (10.1109/MMM.2021.3095699)
- Cripps, S. C. 2021. Iconic circles [microwave bytes]. IEEE Microwave Magazine 22(7), pp. 17-22. (10.1109/MMM.2021.3069605)
- Rubio, J. J. M., Quaglia, R., Piacibello, A., Camarchia, V., Tasker, P. J. and Cripps, S. 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)
- 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. 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)
2020
- Cripps, S. C. 2020. Pushing and pulling [microwave bytes]. IEEE Microwave Magazine 21(10), pp. 14-18. (10.1109/MMM.2020.3008306)
- Collins, D. J., Quaglia, R., Powell, J. and Cripps, S. 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)
- Moreno Rubio, J., Quaglia, R., Baddeley, A., Tasker, P. and Cripps, S. 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., Lees, J., Quaglia, R., Watkins, G. and Cripps, S. 2019. Wideband compact planar balun for applications in outphasing and push-pull amplifiers. Electronics Letters 55(16), pp. 912-914. (10.1049/el.2018.7915)
- Cappello, T., Pednekar, P., Florian, C., Cripps, S., Popovic, Z. and Barton, T. W. 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)
- Quaglia, R., Greene, M. D., Poulton, M. J. and Cripps, S. C. 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)
- Parker, N., Hefford, S., Lees, J., Cripps, S. and Porch, A. 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. -.
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. T. and Cripps, S. 2019. Design and characterisation of an outphasing power amplifier with balun combiner. Presented at: 2019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G), Altanta, GA, USA, 15-16 August 20192019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G). IEEE pp. 1-3., (10.1109/IMC-5G47857.2019.9160351)
2018
- Powell, J. R., Shepphard, D. J., Quaglia, R. and Cripps, S. C. 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)
- Bogusz, A., Costello, Z., Quaglia, R., Bell, J., Lees, J., Tasker, P. and Cripps, S. 2018. Power and efficiency continuous modes in saturated GaN HEMT devices. Presented at: Inmmic 2018, Brive-La-Gaillarde, France, 5- 6 July 2018.
- Collins, D., Quaglia, R., Powell, J. and Cripps, S. 2018. Experimental characterization of a load modulated balanced amplifier with simplified input power splitter. Presented at: APMC 2018, Kyoto, Japan, 6-9 Nov 2018.
2017
- 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)
- 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 20172017 IEEE MTT-S International Microwave Symposium (IMS). IEEE pp. 943-945., (10.1109/MWSYM.2017.8058743)
- 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)
- Cripps, S. C. 2017. Great Equations? [Microwave Bytes]. IEEE Microwave Magazine 18(2), pp. 24-27. (10.1109/MMM.2016.2635924)
- 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. 2016Microwave Conference (EuMC), 2016 46th European. IEEE pp. 405-408., (10.1109/EuMC.2016.7824365)
- 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 20162016 46th European Microwave Conference (EuMC). IEEE pp. 1353-1356., (10.1109/EuMC.2016.7824603)
- 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 2016International Conference for Students on Applied Engineering (ICSAE). IEEE pp. 7-11., (10.1109/ICSAE.2016.7810152)
2016
- Yusoff, Z., Annuar, F. M., Kung, F., Hashim, S. J., Lees, J. and Cripps, S. C. 2016. The effect of tracking generator efficiency to overall RF power amplifier system efficiency. Presented at: 2016 IEEE International Conference on Semiconductor Electronics (ICSE), 17-19 August 20162016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE pp. 344-347., (10.1109/SMELEC.2016.7573662)
- 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 20162016 IEEE MTT-S International Microwave Symposium (IMS). IEEE pp. 1-3., (10.1109/MWSYM.2016.7540265)
- 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)
- 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)
- 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. 20162016 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR). IEEE pp. 49-52., (10.1109/PAWR.2016.7440161)
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 20152015 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 20152015 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
- Yusoff, Z., Lees, J., Chaudhary, M. A., Carrubba, V., Choi, H., Tasker, P. J. and Cripps, S. C. 2013. Simple and low-cost tracking generator design in envelope tracking radio frequency power amplifier system for WCDMA applications. IET Microwaves, Antennas & Propagation 7(10), pp. 802-808. (10.1049/iet-map.2013.0091)
- 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. 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 2013Microwave Measurement Conference (ARFTG), 2013 81st ARFTG. IEEE pp. 1-3., (10.1109/ARFTG.2013.6579040)
- 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 2013Compound Semiconductor Integrated Circuit Symposium (CSICS), 2013 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2013.6659232)
2012
- Carrubba, V., Akmal, M., Quay, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2012. The Continuous Inverse Class-F Mode With Resistive Second-Harmonic Impedance. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1928-1936. (10.1109/TMTT.2012.2189228)
- Carrubba, V. et al. 2012. Continuous-ClassF3 power amplifier mode varying simultaneously first 3 harmonic impedances. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6258343)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A 40W push-pull power amplifier for high efficiency, decade bandwidth applications at microwave frequencies. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest (MTT, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259418)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A Novel Formulation for High Efficiency Modes in Push-Pull Power Amplifiers Using Transmission Line Baluns. IEEE Microwave and Wireless Components Letters 22(5), pp. 257-259. (10.1109/LMWC.2012.2191273)
- Tasker, P. J., Carrubba, V., Wright, P., Lees, J., Benedikt, J. and Cripps, S. C. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS), La Jolla, CA, USA, 14-17 October 2012Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2012.6340048)
2011
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. On the extension of the continuous class-F mode power amplifier. IEEE Transactions on Microwave Theory and Techniques 59(5), pp. 1294-1303. (10.1109/TMTT.2011.2117435)
- Yusoff, Z. B., Akmal, M., Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. The benefit of GaN characteristics over LDMOS for linearity improvement using drain modulation in power amplifier system. Presented at: 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, Vienna, Austria, 18-19 April 20112011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE pp. 109-112., (10.1109/INMMIC.2011.5773334)
- Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. A novel highly efficient broadband continuous class-F RFPA delivering 74% average efficiency for an octave bandwidth. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 20112011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 350-353., (10.1109/MWSYM.2011.5972701)
- Yusoff, Z. B., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. Linearity improvement in RF power amplifier system using integrated Auxiliary Envelope Tracking system. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1752-1755., (10.1109/MWSYM.2011.5972769)
- FitzPatrick, D., Saini, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. A waveform engineering approach to the design of improved efficiency wideband MMIC amplifiers. Presented at: Wireless and Microwave Technology Conference (WAMICON), 2011 IEEE 12th Annual., Clearwater Beach, FL, USA, 18-19 April 20112011 IEEE 12th Annual Wireless and Microwave Technology Conference (WAMICON), Clearwater Beach, FL, 18-19 April 2011. Los Alamitos, CA: IEEE pp. 225-230., (10.1109/WAMICON.2011.5872859)
- Smith, R. M., Cripps, S. C., Tasker, P. J., Benedikt, J. and Lees, J. 2011. A design methodology for the realization of multi-decade baluns at microwave frequencies. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1204-1208., (10.1109/MWSYM.2011.5972702)
- Bell, J. J., Saini, R., Woodington, S. P., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Behavioral model analysis using simultaneous active fundamental load-pull and harmonic source-pull measurements at X-band. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International. New York: IEEE pp. 982-986., (10.1109/MWSYM.2011.5972803)
- 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 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 355., (10.1109/MWSYM.2011.5973350)
- Carrubba, V. et al. 2011. High-speed device characterization using an active load-pull system and waveform engineering postulator. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034553)
- Canning, T. A. J., Almuhaisen, A., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Utilization of RF I-V waveform load-pull information to identify the role FET knee profile has on locating the efficiency maxima. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183864)
- Carrubba, V. et al. 2011. Exploring the Design Space for Broadband PAs using the Novel "Continuous Inverse Class-F Mode". Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 41st European Microwave Conference (EuMC). IEEE pp. 333-336.
- Almuhaisen, A., Lees, J., Cripps, S. C., Tasker, P. J. and Benedikt, J. 2011. Wide band high-efficiency power amplifier design. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 184-187.
2010
- Akmal, M. et al. 2010. The effect of baseband impedance termination on the linearity of GaN HEMTs. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561636. pp. 1046-1049.
- 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 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). Piscataway, NJ: IEEE pp. 509-512., (10.1109/MWSYM.2010.5517696)
- Almuhaisen, A., Wright, P. T., Lees, J., Tasker, P. J., Cripps, S. C. and Benedikt, J. 2010. Novel wide band high-efficiency active harmonic injection power amplifier concept. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 664-667., (10.1109/MWSYM.2010.5514759)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. 2010. Exploitation of active load-pull and DLUT models in MMIC design. Presented at: IEEE Radio Frequency Integrated Circuits Symposium, Anaheim, CA, USA, 23-25 May 2010Proceedings of the 2010 IEEE Radio Frequency Integrated Circuits Symposium May 23-25, 2010, Anaheim, California, USA. Piscataway, NJ: IEEE pp. 487-490., (10.1109/RFIC.2010.5477406)
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2010. The continuous Class-F Mode mode power amplifier. Presented at: European Microwave Conference (EuMC) 2010, Paris, France. Vol. 561630. pp. 1674-1677.
- 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, USA. Vol. 546185.
2009
- Wright, P., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2009. A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA. IEEE Transactions on Microwave Theory and Techniques 57(12), pp. 3196-3204. (10.1109/TMTT.2009.2033295)
- Cripps, S. C., Tasker, P., Clarke, A. L., Lees, J. and Benedikt, J. 2009. On the continuity of high efficiency modes in linear RF power amplifiers. IEEE Microwave and Wireless Components Letters 19(10), pp. 665-667. (10.1109/LMWC.2009.2029754)
- Wright, P. T., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2009. An Efficient, Linear, Broadband Class-J-Mode PA Realised Using RF. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, MA, USA, 7-12 June 2009IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE pp. 653-656., (10.1109/MWSYM.2009.5165781)
2008
- Cripps, S. 2008. Trapwave Inc. [Microwave Bytes]. IEEE Microwave Magazine 9(4), pp. 46-51., article number: 10103186. (10.1109/MMM.2008.924789)
- Lees, J., Williams, T., Woodington, S., McGovern, P., Cripps, S. C., Benedikt, J. and Tasker, P. 2008. Demystifying Device related Memory Effects using Waveform Engineering and Envelope Domain Analysis. Presented at: 38th European Microwave Conference 2008 (EuMC 2008), Amsterdam, The Netherlands. pp. 753-756., (10.1109/EUMC.2008.471562)
Articles
- Yuan, T., Quaglia, R., Chaudhry, K., Azad, E., Powell, J. R. and Cripps, S. C. 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)
- Cripps, S. C. 2023. Swapping tales [Microwave Bytes]. IEEE Microwave Magazine 24(10), pp. 68-72. (10.1109/MMM.2023.3294879)
- Jones, D. R., Brown, P., McFarland, G., Perks, R., Choi, H., Cripps, S. and Porch, A. 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)
- Cripps, S. C. 2022. Still a-masing [microwave bytes]. IEEE Microwave Magazine 24(1), pp. 16-20. (10.1109/MMM.2022.3203943)
- Quaglia, R., Pang, J., Cripps, S. C. and Zhu, A. 2022. Load-modulated balanced amplifier: from first invention to recent development. IEEE Microwave Magazine 23(12), pp. 60-70. (10.1109/MMM.2022.3203940)
- Cripps, S. C. 2022. Phasing out [microwave bytes]. IEEE Microwave Magazine 23(8), pp. 18-22. (10.1109/MMM.2022.3173068)
- Quaglia, R., Powell, J. R., Chaudhry, K. and Cripps, S. C. 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)
- 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. Tuning up [microwave bytes]. IEEE Microwave Magazine 23(2), pp. 16-54. (10.1109/MMM.2021.3125471)
- 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. Vacuous soundings [microwave bytes]. IEEE Microwave Magazine 22(10), pp. 15-20. (10.1109/MMM.2021.3095699)
- Cripps, S. C. 2021. Iconic circles [microwave bytes]. IEEE Microwave Magazine 22(7), pp. 17-22. (10.1109/MMM.2021.3069605)
- Rubio, J. J. M., Quaglia, R., Piacibello, A., Camarchia, V., Tasker, P. J. and Cripps, S. 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)
- 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. 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. 2020. Pushing and pulling [microwave bytes]. IEEE Microwave Magazine 21(10), pp. 14-18. (10.1109/MMM.2020.3008306)
- Collins, D. J., Quaglia, R., Powell, J. and Cripps, S. 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)
- Moreno Rubio, J., Quaglia, R., Baddeley, A., Tasker, P. and Cripps, S. 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)
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. and Cripps, S. 2019. Wideband compact planar balun for applications in outphasing and push-pull amplifiers. Electronics Letters 55(16), pp. 912-914. (10.1049/el.2018.7915)
- Cappello, T., Pednekar, P., Florian, C., Cripps, S., Popovic, Z. and Barton, T. W. 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)
- Quaglia, R., Greene, M. D., Poulton, M. J. and Cripps, S. C. 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)
- Powell, J. R., Shepphard, D. J., Quaglia, R. and Cripps, S. C. 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)
- 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., 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)
- Cripps, S. C. 2017. Great Equations? [Microwave Bytes]. IEEE Microwave Magazine 18(2), pp. 24-27. (10.1109/MMM.2016.2635924)
- 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)
- 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)
- 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)
- 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)
- Yusoff, Z., Lees, J., Chaudhary, M. A., Carrubba, V., Choi, H., Tasker, P. J. and Cripps, S. C. 2013. Simple and low-cost tracking generator design in envelope tracking radio frequency power amplifier system for WCDMA applications. IET Microwaves, Antennas & Propagation 7(10), pp. 802-808. (10.1049/iet-map.2013.0091)
- 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)
- Carrubba, V., Akmal, M., Quay, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2012. The Continuous Inverse Class-F Mode With Resistive Second-Harmonic Impedance. IEEE Transactions on Microwave Theory and Techniques 60(6), pp. 1928-1936. (10.1109/TMTT.2012.2189228)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A Novel Formulation for High Efficiency Modes in Push-Pull Power Amplifiers Using Transmission Line Baluns. IEEE Microwave and Wireless Components Letters 22(5), pp. 257-259. (10.1109/LMWC.2012.2191273)
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. On the extension of the continuous class-F mode power amplifier. IEEE Transactions on Microwave Theory and Techniques 59(5), pp. 1294-1303. (10.1109/TMTT.2011.2117435)
- Wright, P., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2009. A Methodology for Realizing High Efficiency Class-J in a Linear and Broadband PA. IEEE Transactions on Microwave Theory and Techniques 57(12), pp. 3196-3204. (10.1109/TMTT.2009.2033295)
- Cripps, S. C., Tasker, P., Clarke, A. L., Lees, J. and Benedikt, J. 2009. On the continuity of high efficiency modes in linear RF power amplifiers. IEEE Microwave and Wireless Components Letters 19(10), pp. 665-667. (10.1109/LMWC.2009.2029754)
- Cripps, S. 2008. Trapwave Inc. [Microwave Bytes]. IEEE Microwave Magazine 9(4), pp. 46-51., article number: 10103186. (10.1109/MMM.2008.924789)
Conferences
- Jones, D., Cripps, S., Choi, H., Perks, R., Porch, A. and Brown, P. 2024. Novel oscillator for use in near-field microwave microscopy. Presented at: Asia-Pacific Microwave Conference (APMC), 05-08 December 2023Proceedings 2023 Asia-Pacific Microwave Conference (APMC). IEEE pp. 829-831., (10.1109/APMC57107.2023.10439775)
- 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 2024Proceedings 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., Urvoy, J., Powell, J., Bell, J. J., Cripps, S. C., Tasker, P. and Quaglia, R. 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 2024Proceedings 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., Quaglia, R., Cripps, S. C. and Tasker, P. J. 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 20232023 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC). IEEE, (10.1109/INMMIC57329.2023.10321784)
- Urvoy, J., Quaglia, R., Powell, J. R. and Cripps, S. C. 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 2023Proceedings of 53rd European Microwave Conference. IEEE pp. 267-270., (10.23919/EuMC58039.2023.10290592)
- Li, W., Bogusz, A., Lees, J., Quaglia, R., Cripps, S., Montoro, G. and Gilabert, P. L. 2023. Performance modeling and shaping function extraction for dual-input load modulated power amplifiers. Presented at: 2023 IEEE/MTT-S International Microwave Symposium - IMS 2023, San Diego, USA, 11-16 June 2023Proceedings of the 2023 IEEE/MTT-S International Microwave Symposium (IMS). IEEE pp. 203-206., (10.1109/IMS37964.2023.10188039)
- Ghozati, S. U., Quaglia, R., Azad, E., Powell, J., Tasker, P. and Cripps, S. 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.
- Quaglia, R., Powell, J., Chaudhry, K. and Cripps, S. 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 20222022 International Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMiC). IEEE pp. 1-3., (10.1109/INMMiC54248.2022.9762184)
- Parker, N., Hefford, S., Lees, J., Cripps, S. and Porch, A. 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. -.
- Bogusz, A., Lees, J., Quaglia, R., Watkins, G. T. and Cripps, S. 2019. Design and characterisation of an outphasing power amplifier with balun combiner. Presented at: 2019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G), Altanta, GA, USA, 15-16 August 20192019 IEEE MTT-S International Microwave Conference on Hardware and Systems for 5G and Beyond (IMC-5G). IEEE pp. 1-3., (10.1109/IMC-5G47857.2019.9160351)
- Bogusz, A., Costello, Z., Quaglia, R., Bell, J., Lees, J., Tasker, P. and Cripps, S. 2018. Power and efficiency continuous modes in saturated GaN HEMT devices. Presented at: Inmmic 2018, Brive-La-Gaillarde, France, 5- 6 July 2018.
- Collins, D., Quaglia, R., Powell, J. and Cripps, S. 2018. Experimental characterization of a load modulated balanced amplifier with simplified input power splitter. Presented at: APMC 2018, Kyoto, Japan, 6-9 Nov 2018.
- 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 20172017 IEEE MTT-S International Microwave Symposium (IMS). IEEE pp. 943-945., (10.1109/MWSYM.2017.8058743)
- 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. 2016Microwave Conference (EuMC), 2016 46th European. IEEE pp. 405-408., (10.1109/EuMC.2016.7824365)
- 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 20162016 46th European Microwave Conference (EuMC). IEEE pp. 1353-1356., (10.1109/EuMC.2016.7824603)
- 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 2016International Conference for Students on Applied Engineering (ICSAE). IEEE pp. 7-11., (10.1109/ICSAE.2016.7810152)
- Yusoff, Z., Annuar, F. M., Kung, F., Hashim, S. J., Lees, J. and Cripps, S. C. 2016. The effect of tracking generator efficiency to overall RF power amplifier system efficiency. Presented at: 2016 IEEE International Conference on Semiconductor Electronics (ICSE), 17-19 August 20162016 IEEE International Conference on Semiconductor Electronics (ICSE). IEEE pp. 344-347., (10.1109/SMELEC.2016.7573662)
- 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 20162016 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. 20162016 IEEE Topical Conference on Power Amplifiers for Wireless and Radio Applications (PAWR). IEEE pp. 49-52., (10.1109/PAWR.2016.7440161)
- 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 20152015 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 20152015 IEEE MTT-S International Microwave Symposium. IEEE pp. 1-3.
- 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 2013Microwave Measurement Conference (ARFTG), 2013 81st ARFTG. IEEE pp. 1-3., (10.1109/ARFTG.2013.6579040)
- 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 2013Compound Semiconductor Integrated Circuit Symposium (CSICS), 2013 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2013.6659232)
- Carrubba, V. et al. 2012. Continuous-ClassF3 power amplifier mode varying simultaneously first 3 harmonic impedances. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6258343)
- Smith, R. M., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2012. A 40W push-pull power amplifier for high efficiency, decade bandwidth applications at microwave frequencies. Presented at: 2012 IEEE MTT-S International Microwave Symposium Digest (MTT, Montreal, Canada, 17-22 June 2012Microwave Symposium Digest (MTT), 2012 IEEE MTT-S International. IEEE pp. 1-3., (10.1109/MWSYM.2012.6259418)
- Tasker, P. J., Carrubba, V., Wright, P., Lees, J., Benedikt, J. and Cripps, S. C. 2012. Wideband PA design: The "continuous" mode of operation. Presented at: Compound Semiconductor Integrated Circuit Symposium (CSICS), La Jolla, CA, USA, 14-17 October 2012Compound Semiconductor Integrated Circuit Symposium (CSICS), 2012 IEEE. IEEE pp. 1-4., (10.1109/CSICS.2012.6340048)
- Yusoff, Z. B., Akmal, M., Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. The benefit of GaN characteristics over LDMOS for linearity improvement using drain modulation in power amplifier system. Presented at: 2011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits, Vienna, Austria, 18-19 April 20112011 Workshop on Integrated Nonlinear Microwave and Millimetre-Wave Circuits (INMMIC 2011). New York: IEEE pp. 109-112., (10.1109/INMMIC.2011.5773334)
- Carrubba, V., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. A novel highly efficient broadband continuous class-F RFPA delivering 74% average efficiency for an octave bandwidth. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 20112011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 350-353., (10.1109/MWSYM.2011.5972701)
- Yusoff, Z. B., Lees, J., Benedikt, J., Tasker, P. J. and Cripps, S. C. 2011. Linearity improvement in RF power amplifier system using integrated Auxiliary Envelope Tracking system. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1752-1755., (10.1109/MWSYM.2011.5972769)
- FitzPatrick, D., Saini, R., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. A waveform engineering approach to the design of improved efficiency wideband MMIC amplifiers. Presented at: Wireless and Microwave Technology Conference (WAMICON), 2011 IEEE 12th Annual., Clearwater Beach, FL, USA, 18-19 April 20112011 IEEE 12th Annual Wireless and Microwave Technology Conference (WAMICON), Clearwater Beach, FL, 18-19 April 2011. Los Alamitos, CA: IEEE pp. 225-230., (10.1109/WAMICON.2011.5872859)
- Smith, R. M., Cripps, S. C., Tasker, P. J., Benedikt, J. and Lees, J. 2011. A design methodology for the realization of multi-decade baluns at microwave frequencies. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 1204-1208., (10.1109/MWSYM.2011.5972702)
- Bell, J. J., Saini, R., Woodington, S. P., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Behavioral model analysis using simultaneous active fundamental load-pull and harmonic source-pull measurements at X-band. Presented at: 2011 IEEE/MTT-S International Microwave Symposium, Baltimore, MD, USA, 5-10 June 2011Microwave Symposium Digest (MTT), 2011 IEEE MTT-S International. New York: IEEE pp. 982-986., (10.1109/MWSYM.2011.5972803)
- 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 Presented at Seigel, P. et al. eds.2011 IEEE/MTT-S International Microwave Symposium - MTT 2011. New York: IEEE pp. 355., (10.1109/MWSYM.2011.5973350)
- Carrubba, V. et al. 2011. High-speed device characterization using an active load-pull system and waveform engineering postulator. Presented at: 2011 77th ARFTG Microwave Measurement Conference (ARFTG), Baltimore, MD, USA, 10 June 2011Design and Measurement of Microwave Systems - Proceedings of the 2011 77th ARFTG Microwave Measurement Conference (ARFTG). Los Alamitos, CA: IEEE, (10.1109/ARFTG77.2011.6034553)
- Canning, T. A. J., Almuhaisen, A., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. J. 2011. Utilization of RF I-V waveform load-pull information to identify the role FET knee profile has on locating the efficiency maxima. Presented at: 2011 78th ARFTG Microwave Measurement Symposium (ARFTG), Tempe, AZ, USA, 1-2 December 2011Proceedings of the 2011 78th ARFTG Microwave Measurement Symposium (ARFTG) - High Power RF Measurement Techniques. Los Alamitos, CA: IEEE, (10.1109/ARFTG78.2011.6183864)
- Carrubba, V. et al. 2011. Exploring the Design Space for Broadband PAs using the Novel "Continuous Inverse Class-F Mode". Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 41st European Microwave Conference (EuMC). IEEE pp. 333-336.
- Almuhaisen, A., Lees, J., Cripps, S. C., Tasker, P. J. and Benedikt, J. 2011. Wide band high-efficiency power amplifier design. Presented at: 6th European Microwave Integrated Circuits Conference (EuMIC) 2011, Manchester, UK, 10-11 October 2011Proceedings of the 6th European Microwave Integrated Circuits Conference (EuMIC). Los Alamitos, CA: IEEE pp. 184-187.
- Akmal, M. et al. 2010. The effect of baseband impedance termination on the linearity of GaN HEMTs. Presented at: European Microwave Conference 2010, Paris, France. Vol. 561636. pp. 1046-1049.
- 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 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). Piscataway, NJ: IEEE pp. 509-512., (10.1109/MWSYM.2010.5517696)
- Almuhaisen, A., Wright, P. T., Lees, J., Tasker, P. J., Cripps, S. C. and Benedikt, J. 2010. Novel wide band high-efficiency active harmonic injection power amplifier concept. Presented at: IEEE MTT-S International Microwave Symposium, Anaheim, CA, USA, 23-28 May 20102010 IEEE MTT-S International Microwave Symposium Digest (MTT 2010). New York: IEEE pp. 664-667., (10.1109/MWSYM.2010.5514759)
- FitzPatrick, D. M., Williams, T., Lees, J., Benedikt, J., Cripps, S. C. and Tasker, P. 2010. Exploitation of active load-pull and DLUT models in MMIC design. Presented at: IEEE Radio Frequency Integrated Circuits Symposium, Anaheim, CA, USA, 23-25 May 2010Proceedings of the 2010 IEEE Radio Frequency Integrated Circuits Symposium May 23-25, 2010, Anaheim, California, USA. Piscataway, NJ: IEEE pp. 487-490., (10.1109/RFIC.2010.5477406)
- Carrubba, V., Clarke, A. L., Akmal, M., Lees, J., Benedikt, J., Tasker, P. and Cripps, S. C. 2010. The continuous Class-F Mode mode power amplifier. Presented at: European Microwave Conference (EuMC) 2010, Paris, France. Vol. 561630. pp. 1674-1677.
- 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, USA. Vol. 546185.
- Wright, P. T., Lees, J., Tasker, P. J., Benedikt, J. and Cripps, S. C. 2009. An Efficient, Linear, Broadband Class-J-Mode PA Realised Using RF. Presented at: IEEE/MTT-S International Microwave Symposium 2009, Boston, MA, USA, 7-12 June 2009IEEE MTT-S International Microwave Symposium Digest, 2009. MTT '09. Los Alamitos, CA: IEEE pp. 653-656., (10.1109/MWSYM.2009.5165781)
- Lees, J., Williams, T., Woodington, S., McGovern, P., Cripps, S. C., Benedikt, J. and Tasker, P. 2008. Demystifying Device related Memory Effects using Waveform Engineering and Envelope Domain Analysis. Presented at: 38th European Microwave Conference 2008 (EuMC 2008), Amsterdam, The Netherlands. pp. 753-756., (10.1109/EUMC.2008.471562)
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)