Chirp Bandwidth Estimation of Pulsed IMPATT Oscillator at 94 GHz Window: A Simplified Approach

Abstract

Chirp bandwidth viz. intra-pulse oscillation frequency variation is an inherent property of IMPATT devices operating in pulsed mode to obtain high peak-power. In this paper, a simplified approach to compute chirp bandwidth, without the detailed knowledge of the embedded W-band circuit, is presented. The analysis has been based on a small-signal simulation model and transient thermal model of a typical silicon double-drift region structure at 94 GHz frequency band. The diode has been optimized for an optimum punch-through factor. It is observed that the diodes have a specific optimum temperature range of operation, to achieve a stable and high-output operation. The computed chirp bandwidth of the order of 1.8 GHz agrees reasonably well with the values reported in the literature. Variation of chirp bandwidth with frequency is also reported in this paper.

Keywords:

• Chirp bandwidth
• Double drift diode
• High-power operation
• Intra-pulse junction temperature
• Pulsed IMPATT
• Temperature variation of admittance and impedance

Additional information

Notes on contributors

Arijit Das

Arijit Das obtained M. Sc Degree in Electronic Science in 2005 and M. Tech Degree in Radiophysics and Electronics in 2007 (Both from University of Calcutta, India). He is presently working as a full-time Senior Research Fellow (SRF) in the Centre for Millimeter-wave Semiconductor Devices and Systems, University of Calcutta. He has published a good number of research papers in reputed international journals and reviewed conference-proceedings. His research interests include Design and Fabrication of MM-wave solid-state oscillators.

E-mail: [email protected]

Diptadip Chakraborty

Diptadip Chakraborty obtained his M.Sc. Degree in Electronic Science in 2005 and M. Tech Degree in Radiophysics and Electronics in 2007 (Both from University of Calcutta, India).

He is presently working as a full-time Senior Research Fellow (SRF) in the Centre for Millimeter-wave Semiconductor Devices and Systems, University of Calcutta.

He has published a good number of research papers in reputed international journals and reviewed conference-proceedings. His research interests include Design and Fabrication of MM wave solid state devices.

E-mail: [email protected]

Moumita Mukherjee

Moumita Mukherjee completed her higher-education from Presidency College, Kolkata, India, University of Calcutta and obtained her Ph.D. (Tech) degree in Radio Physics and Electronics, University of Calcutta in 2010. Till June 2010, she worked as DRDO-Senior research fellow, under Visva Bharati University, Jadavpur University and Calcutta University. From June, 2010, she is attached with CMSDS, University of Calcutta, as Research Associate (RA-). Her research interest is focused on the design and fabrication of WBG semiconductor-based solid-state devices in the MM-wave and Terahertz region, Nanoscale device design and fabrication and Microwave & Millimeter-wave Photonics.

She has authored in more than 85 research papers published in international refereed journals and IEEE-proceedings. She is the author of a book on “Fundamentals of Engineering Physics”, 6 book chapters on ‘WBG-semiconductor devices’ and worked as Chief-Editor of two research-books on ‘Silicon Carbide’ and ‘Microwave devices’ published from Vienna, UK. She has received ‘IEEE-Best paper award’ in IEEE-International conferences in 2009 and 2010. Her biography was published by Marque’s Who’s Who in Science and Engineering (USA) and American Biographical Institute (ABI-USA). She is the Member of IEEE (USA), IEEE-ED society, IEEE-MTTs, and Indian Science Congress.

E-mail: [email protected]

Parthojyoti Datta

Parthajyoti Datta joined SSPL, Delhi, as Sci B in 1980. He obtained his PhD from University of Delhi in 1982. He has worked for the fabrication of silicon-based devices like fast silicon p-i-n detectors, quadrant detectors, W band IMPATT diodes, bulk window W band SPST switches, Ka-band RF MEMS components. His current area of work is in MEMS-based devices and structures in silicon.

E-mail: [email protected]

U. C. Ray

U. C. Ray has obtained his M.Tech degree from IIT, Kharagpur and Ph.D from the Faculty of Technology, University of Delhi. He joined Solid State Physics Laboratory, Delhi in November 1976 and worked on the modelling and characterization of a variety of semiconductor devices. Presently, he is the Associate Director of this organization. He has published over 30 research papers in peer reviewed journals and international conference-proceedings. His present interest includes microwave/ mm-wave devices, MMICs, RF MEMS, Ferrite Phase Shifters and Instrumentation.

E-mail: [email protected]