Dr Chris Oxley

Job: Reader in Electronic Devices

Faculty: Technology

School/department: School of Engineering and Sustainable Development

Research group(s): Centre for Electronic and Communications Engineering

Address: De Montfort University, The Gateway, Leicester, LE1 9BH

T: +44 (0)116 257 7078

E: choxley@dmu.ac.uk

W: www.dmu.ac.uk/cece


Personal profile

Dr Chris Oxley's research work has spanned a large area in RF and microwave devices and circuits. It includes the trapped avalanche plasma trigger transit (TRAPATT), the impact ionization avalanche transit time (IMPATT), Gunn diodes, GaAs MESFETs, travelling wave FET structures including the development of the linear gate transistor (LGT). Circuit development included microstrip and waveguide development to 40GHz including ferrite circulators/isolators.

More recently Chris has been involved with electrical equivalent circuit modelling of GaN transistor structures and the measurement of the temperature profile of a range of electronic devices including GaN, GaAs, silicon, monolithic microwave integrated circuits (mmic) and microelectromechanical devices (MEMs). Further interests include microwave characterisation of conducting fabrics and micro-coolers. 

Research group affiliations

Centre for Electronic and Communications Engineering (CECE)

Key research outputs

  • C.H. Oxley. A.M. Howard & J.J. Purcell. "Design and Performance of I-Band TRAPATT Diodes and Amplifiers", IEEE Trans. MTT May 1979, pp 463-471.
  • A.J. Holden. D.R. Daniel. I. Davies. C. H. Oxley & H.D. Rees, "Gallium Arsenide Travelling-Wave Field-Effect Transistors IEEE Electron Devices January 1985, pp 61-66.
  • C. H. Oxley, M. Uren ‘Measurement of unity gain cut-off frequency and saturation velocity of a GaN HEMT transistor’ IEEE Trans ED, February 2005, pp 165-170.
  • C. H. Oxley, M. Uren, A. Coates and D. G. Hayes ‘On the temperature and carrier density dependence of electron saturation velocity in a AlGaN/GaN HEMT’ IEEE Trans ED March, 2006, pp 565-568.
  • R Axell, R Hopper, P Jarritt, and C H Oxley ‘A novel method for more accurately mapping the surface temperature of ultrasonic transducers’ Journal of Ultrasound in Medicine and Biology’ ,Vol 37,Nos 10, Oct 2011.
  • A Khalid, C Li, V Papagerorgiou, G M Dunn, M Steer, T G Thayne, M Kuball C H Oxley, M Montes-Bajo, A Stephen, J Glover and D R S Cumming. ‘164GHz In0.53Ga0.47As Planar Gunn Diodes’ accepted for publication with IEEE, EDL Aug 2012
  • Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate ☆Veeren M. Chauhana, Richard H. Hopperb, Syed Z. Alib, Emma M. Kingc, Florin Udreab, d, Chris H. Oxleye, & Jonathan W. Aylotta,  Sensors and Actuators B: Chemical, March 2014.
  • A. Khalid, G. M. Dunn, R. F. Macpherson, S. Thoms, D. Macintyre, C. Li, M. J. Steer, V. Papageorgiou, I. G. Thayne, M. Kuball, C. H. Oxley, M. Montes Bajo, A. Stephen, J. Glover, and D. R. S. Cumming, “Terahertz oscillations in an In0.53Ga0.47As submicron planar Gunn diode,” J. Appl. Phys., vol. 115, no. 11, p. 114502, Mar. 2014.
  • J Glover, A Khalid, A Stephen, G Dunn ,D R S Cumming & C H Oxley ‘Micro-coolers fabricated as a component in an integrated circuit’ IOP Semicond. Sci. Technol. 30, Nov 2014.
  • M Maricar, A Khalid, G Dunn, D R S Cumming & C H Oxley ‘Experimentally estimated dead space for GaAs and InP based planar Gunn diodes’ IOP Semicond. Sci. Technol. 30, Nov 2014

Research interests/expertise

  • Infrared Microscopy, RF and microwaves devices and circuits, gallium nitride (GaN) devices

Areas of teaching

RF and microwaves, analogue electronics, electromagnetics, research methods.


PhD, BSc (Hons) in Physics

Courses taught

High frequency technology (final year BEng electronics).

Analogue electronics (1st year BEng engineering).

Electromagnetism (2nd year BEng electronics 2009).

Electronics for mechatronics (MSc).

Individual projects (MSc, final year BEng engineering).

Research Methods (MSc Electronics, Communications, Mechanical and Mechatronics).

Group Projects (MEng 2014/2015).

Honours and awards

Lord Stafford Award, Aug 2009

Membership of external committees

Broadband wireless forum.

GaN research forum.

KTN nanotechnology.

KTN material.

Representative for De Montfort University at Nottingham eminate (nanotechnology 2007 2009).

Membership of professional associations and societies

FIEI (since 1991), CEng (since 1978), EUR ING (since 1992)

Conference attendance


1)    R. Chapman. J. Heighway & C.H. Oxley.“High Compression Ratio Dispersive Delay Lines” IOP Acoustic Sine wave Colloquium, November 1971. Presented.

2)    J. Heighway & C.H. Oxley "Matching Techniques for Pulsed Compression Filters" IEE  Colloquium on Acoustic Surface Wave Devices and Applications.

3)    C. H. Oxley. A.M. Howard & J.J. Purcell. “High Efficiency X-Band TRAPATT Amplifiers and Oscillators”, EMC Rome 1976. Presented.

4)    J. Purcell & C.H. Oxley "High Efficiency X-Band TRAPATT Oscillators" IEE Colloquium. January 1976.

5)    C. H. Oxley & J.J. Purcell X-Band TRAPATT Amplifiers" lEE Colloquium on TRAPATT Diodes and Circuits" 1977. Presented.

6)    C. H. Oxley & T.J. Brazil "Ferrite Microstrip Circuits for Solid State Oscillators and Amplifier Applications at Frequencies up to 18GHz". 5th Specialist Workshop on Active Microwave Semiconductor Devices, Venice 1978. Presented.

7)    C.H. Oxley et al. "Q-Band (26-40GHz) FETs" IEDM Digest. Washington. December 1981. Presented.

8)    C.H. Oxley. "Q-Band Microstrip Techniques", IEE Colloquium Digest. April 1982. Presented.

9)     J. Arnold. P. Forrest. D. Daniel. R. Bennett & C.H. Oxley."HF GaAs FET Amplifiers", IEE Colloquium Digest.

10) A.J. Holden, D.R. Daniel & C.H. Oxley. "Distributed Effects at High Frequency in Active and Passive Microwave Circuits", IEE Colloquium, April 1983.

11) J J. Arnold & C.H. Oxley "High Gain Temperature Compensated EHP GaAs MESFET Amplifier", EMC Paris 1984.

12) I. Davies. R. Bennett. D. Brambley. J. Joshi. A. Powell & C.H. Oxley. "Low Noise K-Band Submicron FET showing 0.8dB Noise Figure at 77k". European Workshop’’ 1984.

13) A.J. Holden & C.H. Oxley. "Computer Modelling of Travelling Wave Transistors"  International Conference on Simulation of Semi-conductor Devices Swansea July 1984.

14) D. Scott. A.H. Moore. I. Griffith, R. Griffiths. R.S. Sussman & C.H. Oxley "M.O.C.V.D. Growth of AllnAs/GalnAs MESFET Heterostructures" ESSDENC, 1985.

15) I. Davies. D. Brambley. R. Bennett. A. Powell & C.H. Oxley, "The Design and Microwave Performance in Q-Band of 0.3 Micron Gate GaAs MODFETs" ESSDENC 1985.

16) I. Davies. J. King. P. Medhurst & C.H. Oxley. "Design and Performance of GaAs Power FETs from C to Q Band" IEE Colloquium May 1985. Presented.

17) I. Davies. J. King. P. Medhurst & C.H. Oxlev, "Design and Performance of GaAs Power FETs from C to Q Band", IEE Colloquium May 1985.

18) C.H. Oxley & I. Davies, "Travelling Wave FETs" IEE Colloquium April 1985. Presented.

19) I. Davies. A. Holden. S. Cotten. B. Wheeldon & C.H. Oxley."A Comparison between Modelled and Experimental High-Frequency MESFET" IEE Colloquium. 1985.

20) P. Cooper. R. Eaton & C.H. Oxley. "Intelsat 6 - 4GHz Monolithic Transponder". IEE Colloquium May 1986.

21) J. King, P. Medhurst, J. Metcalfe, I. Davies, A. Holden & C.H. Oxley. "Design of Pre-matched X-Band GaAs FETs" IEE Colloquium May 1986. Presented.

22) C.H. Oxley, “Performance of GaAs Power FETs under Pulse Conditions", IEE Colloquium May 1986. Presented.

23) C. Wilkinson & C.H. Oxley, "Ultra-short Gate Length FETs for Millimetre-wave ICs" IEE Colloquium March 1986.

24) C.H. Oxley et al, "Power Transistor Packaging". IEE Colloquium. April 1986. Presented.

25) C.H. Oxley, "Active Devices Suitable for Millimetric Wave Operation" IEE Colloquium, November 1986. Presented.

26) P. Tombs. K. Adams. J. Binley & C.H. Oxley. "A Low Cost Broadband FET Voltage Controlled Oscillator", Military Microwaves Conferences Proceedings July 1988.

27) S. Redfern, C. H. Oxley, D. Dawson, J. Bird, G. Hilder, B. Prime, T. Brown, D. Spencer. "An Automotive 77GHz Radar System Designed for Volume Manufacture”. Paper presented at the Microwaves and RF conference. September 1999.

28) C. H. Oxley, S. Redfern, E. Dawson, J. Bird, B .Prime, T. Brown and D. Spence “An Automotive 77GHz Radar Sensor designed for Volume Manufacture” Published in Telematics Automotive Proceedings, April 2000. Presented.

29) C. H. Oxley and O. Buiu “Will GaN replace GaAs as the semiconductor Material for Microwave Devices” System on Chip for a Connected World Conference Proceedings, Oct 2000, pages 527-538. Presented.

30) C. H. Oxley “GaN Technology” Workshop on RF Circuit Technology Proceedings Cambridge April 2001. Presented.

31) C. H. Oxley, M. Uren and D. Hayes, “Gallium Nitride Technology now and in 3 Decades” (M. Uren and D. Hayes are with QinetiQ) Workshop on RF Circuit Technology Proceedings Cambridge. Published in the workshop proceedings, March 2002. Presented.

32) C. H. Oxley ‘Noise performance and Applications of Gallium Nitride HEMT Transistors’ Wireless Design Conference Proceedings, May 2002 International Conference. Presented.

33) C. H. Oxley, M. Uren The performance of gallium nitride transistors with a view to broad-band wireless communications’ (M. Uren is with QinetiQ) Invited paper at the Wireless Broadband forum at Cambridge Nov 2002 published in the proceedings. Presented.

34) C. H. Oxley and J. Bourrigaud ‘GaN components for broadband wireless’ Invited paper at the Wireless Broadband forum Cambridge Nov 2003, published in the proceedings Nov 2003. Presented.

35) T Martin1, M J Uren1, R S Balmer1, D Soley1, D J Wallis1, K P Hilton1, J    OMaclean1,A G Munday1, A J Hydes1, D G Hayes1, C H Oxley2, P McGovern3, P J Tasker3‘GaN HFT development at QinetiQ’ Proceedings of European Microwave Conference, Sept 2005.

36) R. Hopper and C. H. Oxley ‘Infrared microscopy – a tool for the manufacturing environment’, to be published in the proceedings 5th International conference on manufacturing research, Sept 2007.

37) C. H. Oxley and R. Hooper ‘Infrared thermal measurements on electronic devices’, Poster session on microscopy, Oxford, June 2007. Presented.

38) R. Hopper and C. H. Oxley ‘Thermal measurement a requirement for monolithic microwave integrated circuit design’ ARRMS proceedings, April 2008.

39) C. H. Oxley R. Hopper and G. A. Evans ‘Improved infrared (IR) microscope measurements for the micro-electronic industry’ IMAC Proceedings, Sept 2008, pp 215- 218. Presented.

40) C. H. Oxley, R. Hopper, and G. A. Evans ‘’ IR microscopy of electronic devices” Thermal workshop Nov 2008. Presented.

41) C. H. Oxley, R. H. Hopper and G Evans ‘Improved Infra-red Microscopy for Thermal Mapping of Electronic Devices including MEMS and Photonic Devices’, KTN workshop on nanotechnology in European Semiconductor Conference in Cardiff, 2009.(Invited paper). Presented.

42) C H Oxley, R H Hopper and G. A. Evans ‘Thermal Imaging of Electronic Devices’ Workshop Imaging Special Interest Group. INET meeting. Sutton Donnington, 3rd March 2010. Presented.

43) Brady, J.  King, C H Oxley and T J Brazil ‘Small and Large Signal Modelling of GaN HEMTs’ Emerging Semiconductor devices and techniques workshop at DMU Sept 2010.

44) C H Oxley R H Hopper and G A Evans ‘Device Thermography using Infra-Red Microscopy’ Emerging Semiconductor Devices and Techniques Workshop at DMU, Sept 2010. Presented.

45) R. H. Hopper, I Haneel, S. Ali, F. Udrea and C. H. Oxley ‘ Improved IR surface thermal measurements of CMOS MEM’S Devices’ to be present and published in the proceedings of the Therminic Conference in Barcelona, Oct 2010.

46) C H Oxley ‘Nano-electronics’ IEMRC, Nov 2010. Presented.

47) R H Hopper, D Prime and C H Oxley, ‘Improved infrared temperature measurements on RF devices’ published in the ARRMS proceedings, Nov 2010. (best paper award).

48) R H Hopper, J Glover, G A Evans and C H Oxley ‘Thermal measurement of RF and microwave devices using a novel thermal probe’ RF and Microwave Workshop, University of Glasgow, March 30th, 2011.

49) R Axell, R Hopper, P Jarritt, P White and C H Oxley ‘How hot does my ultrasound transducer really get’ European Medical Physics and Engineering Conference, Trinity College, Dublin, Ireland, Sept 2011.

50) R. Hopper, J Glover and C H Oxley ‘Novel thermal particle sensor for measuring the temperature of power device modules’, iPower showcasing UK power electronics, University of Warwick, 30th Nov to 1st Dec, 2011.

51) M Montes, G Dunn, A Stephen, A Khalid, C Li, D Cumming, C H Oxley, R Hopper, and M Kuball ‘Impact Ionisation on Planar GaAs Gunn Diodes: Analysis and Reduction by Anode Design’ ISCS Poster, USA, 2012.

52) J Glover, R Hopper, A Khalid, D Cumming, M Montes, M Kuball, G Dunn, A Stephen and C H Oxley ‘Novel Infra-Red (IR) Thermal Measurements on GaAs Micro-coolers’ ARMMS, Nov 2012.

53) J Glover, R Hopper, A Duffy and C H Oxley ‘Infrared thermography for Power over Ethernet (PoE) reference measurements. IEEE EMC conference, USA, Nov 2012.

54) A. Al-Dabbach, H Sasse, M Al-Asadi, C H Oxley and A Duffy ‘A review of the origin and modelling of non-linear behaviour in semiconductor devices’. IEEE EMC conference, USA, Nov 2012.

55) A. Aboutaleb and C H Oxley ‘Microwave Dielectric Measurement of Solids and Liquids over 1 to 4 GHz using Transmission Line Technique and Coaxial Cavity, ARMMS conference, April 2013.

56) M Maricar, J Glover, G Evans, Ata-ul-Khalid, Chong Li, D Cumming and C H Oxley ‘Planar Gunn Diode Characterisation and Resonators’ 4th annual IET workshop on RF and miili-metric passive components, Birmingham,18th March, 2013.

57) A Khalid, J Glover, R Hopper, V Papageorgious, M Montes, M Kuball, G Dunn, A Stephen C H Oxley, and D Cumming ‘Fabrication of integrated planar Gunn diode and micro-cooler on GaAs substrate’ ISCS conference, Japan, May 2013.

58) J Glover, A Stephen+, G Dunn+, M Montes*, M Kuball*, A Khalid**, D Cumming** and C H Oxley  Novel Thermal Management of Power Electronic Devices: High Power High Frequency Planar Gunn Diodes, 'EPSRC National Centre for Power Electronics Launch Event,  Nottingham University 

59) J Glover, M Maricar and C H Oxley High emissivity micro-particles sensors enabling high accuracy, point, thermal profiling, Research to Industry R2i2 Electronics Conference, University of Loughborough.  

60) J Glover, C H Oxley, A Khalid, D R S Cumming, M Montes, M Kuball, A Stephen, and G M Dunn ‘Analysis to determine external loading on wafer-based GaAs micro-coolers’ IeMRC conference Loughborough University.

61) M Maricar, J Glover, G Evans, A Khalid, V Papageorgiou, D Cumming and C H Oxley ‘Improved coplanar waveguide resonator design for milli-metric application’, IeMRC conference Loughborough University.

62) Li-Ju Wei and C H Oxley ‘Generation of smart implants using direct writing additive manufacturing approach’, IeMRC conference, Loughborough University, Sept 2013.

63) M. I. Maricar, J. Glover, G. A. Evans, A. Khalid, V. Papageorgiou, L. Chong, G. Dunn, and C. H. Oxley, “Planar Gunn diode characterisation and resonator elements to realise oscillator circuits,” in International Conference on Advanced Nanomaterials & Emerging Engineering Technologies ICANMEET-2013, 2013, pp. 674–678.

64) M Maricar, A Khalid, D R S Cumming & C H Oxley ‘Second harmonic extraction of planar Gunn diode by using resonatoes for milli-metric wave applications’ ARMMS conference, Nov 2014, Bedfordshire, UK.

Consultancy work

We have actively collaborated with the following companies: Astrium (Portsmouth), Filtronic Broadband, e2v Ltd (Lincoln), Filtronic Components, CIP, Silson, QinetiQ, Quantum Focus (USA), Labtech, SISA, Olaro (was Bookham), LA amplifiers, National Physics Laboratory (NPL), RF Diamond Devices, Honeywell, TriQuint (USA) and MACOM. etc.

Current research students

James Glover ‘‘Novel thermal management of power devices: high power high frequency planar Gunn diodes’ starting Oct 2010 (first supervisor).

Eric Wei ‘Sensible Medical Implant Device with Additive Direct Write Technology, (first supervisor) 2012.

Prakash Pandey ‘Infra-red temperature measurements on electronic devices’ started January 2015 (first supervisor).

Clive Collins ‘Using trees as antenna’ MPhil (first supervisor).

Externally funded research grants information

2001 EPSRC (GR/R21073/01), (start ’91 and completed Aug 2004) ‘Large signal model, including temperature effects for gallium nitride power HEMT’. EPSRC final report – tending to outstanding. (Principal investigator). Industrial collaboration QinetiQ and Marconi Research.

2004 KTP (nos. 4256) in support to lead academic on the microwave measurement of conducting fabrics.

2005 EPSRC (EP/C511085/1) over 3yrs starting April 2005.‘Accurate and repeatable measurement of the thermal profile of RF solid state devices (transistors, 3D MMIC etc) under active operation’. Principal investigator. Industrial collaboration e2v technologies, who also financial supported the project.

2009 Innovation Fellowship (HIRF 410) ‘IR temperature measurement’. Principal investigator.

2009 EPSRC (EP/HO12966/1) ‘Novel thermal management of power devices: high power high frequency planar Gunn diodes’. Part of £1.1 million grant in collaboration with universities of Bristol (lead university), Glasgow, and Aberdeen. Principal investigator.

2009 TSB feasibility study with CIP ‘Thermal management for low power next generation optical access technologies’. Principle Investigator.

Internally funded research project information

2010 RIF study ‘Enhancing the IR micro-sensor technology to more accurately temperature profile electronic devices’.

2010 PhD student university granted bursary. ‘Harmonic extraction from Gunn diode to obtain 300GHz oscillator.

2011 RIF study 'Thermal Characterisation of Semiconductor Devices using Fluorscent Nano-Particle Sensors'.

2012 RIF Study ‘Terahertz solid state Gunn sources'.

2014/2015 RIF study ‘Linear gate transistor (LGT)’,

2015 PhD student university bursary ‘Thermal measurement of electronic devices using infra-red microscopy’.

Published patents

1)    Linear Gate Transistor (International 4675712)

2)    Microstrip Balun Circuit. (GB 8521727; Eur 86306357)

3)    Trapatt Circuit Configuration (GB 5678943)

4)    A new emissivity measurement technique (GB 07207962)

5)    A new high resolution IR measurement technique (GB0821112.0)

Professional esteem indicators

I have served on a number of EPSRC panels, 2006, 2007 and 2008.

Served as an expert evaluator on the review panel meetings in Brussels for FP7 Space Technology Programme in 2009 and 2011 respectively.

Served on the IeMRC proposal evaluation panel in October 2011.

I am a regular reviewer for American Instutue of Physics (Journals ), also review for electronic letters, IEEE reliability, IEEE ED letters, IEEE MTT, solid state electronics, IET micro and nano etc.

On the reader panel for Nature from 2010 to 2011.

External PhD examiner.

Review book proposal for Cambridge university press.

I am external examiner for Physics to Aberdeen University.

I am external examiner for MSc Microwave Communication Engineering at University of Cardiff. 

I took part as expert evaluator for Fondecyt National Research Funding Competition (Chile) in 2012.

Co-authored (invited) a chapter ‘Improved infrared imaging of semiconductor devices’ in Microscope: Advances in Scientific Research and Education’, November 2014.

Invited as Technical Coordinator for ARMMs conference in November 2015.

Case studies

A.J. Holden & C.H. Oxley "Travelling Wave GaAs Transistors" Allen Clarke Research Centre Annual Review. 1984, pp 89-94.

C.H. Oxley, "Millimetric Wave Gallium Arsenide FETS" Allen Clarke Research Centre. Annual Review, 1985, 97-104.

K. Adams & C.H. Oxley. "Broadband FET VCO Design" Electronic Engineering February 1989.

K. Adams & C.H. Oxley "Broadband FET VCO Design" Microwaves & RF Engineering February 1989.

A summary of presented work GaN along with private communication was published in a review article Si, SiGe, GaAs in the French electronics paper Electronique International 11th Jan 2001, nos 416.

C H Oxley and R H Hopper ‘Micro-Scale Infrared Thermal Characterisation of Electronic Devices’ KTN Focus publication, April 2010, pp 16 to 19.

C H Oxley ‘Nanoelectronics’ IOM3 conference for teachers, Oct 13th 2010, Grantham.

C H Oxley, R Hopper, D Prime, M Leaper, G Evans and A Levick ‘Probe propels IR thermal microscopy to a new level’ Compound Semiconductor, Jan/Feb 2011, pages 33 – 36.

Leading and organising Electronics Workshop (with visiting international and national speakers) at De Montfort University.

Organise external workshop for Electronic final year students, and research students on network analyses with Rohde and Schwarz. This was extended in 2012 to the East Midlands (Universities and Industry).


1)    Reader (Electronic Devices), 2010.

2)    Principal Lecturer (De Montfort University from Aug 2005).

3)    Senior Lecturer (De Montfort University from Oct 1999 to August 2005).

4)    A successful career in research, development and manufacturing of RF and microwave electronic devices in industry (1970 to 1999).

i) Project Manager GEC Plessey Semiconductor (1997-1999)

ii) Operations Manager Elettronica (UK) (1989-1997)

iii) Semiconductor Technology Manager Plessey Microwaves (1985-1989)

iv) Chief Physicist (III-V transistors), Plessey Caswell (1980 – 1985)

v) Junior to Principal Scientist, Plessey Caswell (1970 -1980)


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