Theoretical and experimental investigations have been carried out for V-band (50-75 GHz) silicon double drift flat profile (DD) and double low high low (DLHL) IMPATT diodes. The theoretical designs have been used for the experimental realisation of the diodes for CW operation. The epitaxial layers were grown by silicon molecular beam epitaxy which enabled the realisation of the complex DLHL profile at millimetre-wave frequencies in the silicon material system for the first time. The maximum obtained conversion efficiency is 14.3%. A comparison of theoretical and experimental results for both types of diodes shows general agreement and the superiority of the DLHL structure. © 1991, The Institution of Electrical Engineers. All rights reserved.

J P BANERJEE

J F LUY

F SCHAFFLER

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Electronics Letters

A four-level optimization technique has been used to design a double low-high-low (DLHL) impact avalanche transit time (IMPATT) diode based on Si for 60 GHz operation. Initially the position of the charge bumps in both "- and p-epitaxial layers followed by the widths of those and the ratio of high to low doping concentrations have been varied subject to obtain the maximum large-signal DC to RF conversation efficiency from the device. Finally the bias current density is varied within a specified range to obtain the optimum value of it for which the DC to RF conversation efficiency of the device is maximum. The above mentioned four optimization steps have been repeated until the method converges to provide a stable optimized DC to RF conversion efficiency. A large-signal simulation technique based on non-sinusoidal voltage excitation (NSVE) model developed by the authors is used for this purpose. The large-signal properties of the optimized DLHL Si IMPATT have been simulated and those are compared with the experimental results reported earlier. The said comparison shows that the optimized DLHL diode is capable of delivering significantly higher RF power output with greater DC to RF conversion efficiency at 60 GHz as compared to its un-optimized counterpart. © 2015 IEEE.

Proceedings of the 2015 3rd International Conference on Computer, Communication, Control and Information Technology, C3IT 2015

Design optimization and large-signal simulation of DLHL Si IMPATT diode at 60 GHz

Extensive simulation experiments are carried out for the first time, to study the optical modulation of the high- frequency characteristics of III-V GaN-(gallium nitride) based top-mounted and flip-chip IMPact Avalanche Transit Time (IMPATT) oscillators at MM-wave window frequency (140.0GHz). It is found that the un-illuminated GaN IMPATT is capable of delivering a RF power of 5.6 W with an efficiency of 23.5% at 145.0GHz. Frequency up-chirping of 6.0GHz and a degradation of RF power output by almost 15.0% are further observed in case of photo-illuminated FC IMPATT. The study reveals that compared to predominate electron photocurrent in top-mounted IMPATT, photo-generated leakage current dominated by hole in flip-chip IMPATT has more pronounced effect on the GaN-based device as regards the frequency chirping and decrease of negative conductance and total negative resistance per unit area of the device. The inequality in the magnitudes of electron and hole ionization rates in the wide band gap semiconductor has been found to be correlated with the above results. The study reveals that GaN IMPATT is a potential candidate for replacing conventional IMPATTs at high-frequency operation. These results are useful for practical realization of optically controlled GaN-based high-power IMPATTs for application in MM-wave communication systems. © 2010 Cambridge University Press and the European Microwave Association.

Journal	Electronics Letters
Publisher	-
ISSN	0013-5194