Concerning the maximum frequency limits of Gunn operators

Macpherson, R.F., Dunn, G.M., Khalid, A.-u.-H. and Cumming, D. R.S. (2015) Concerning the maximum frequency limits of Gunn operators. Journal of Terahertz Science and Electronic Information Technology, 13(3), pp. 389-395.

Macpherson, R.F., Dunn, G.M., Khalid, A.-u.-H. and Cumming, D. R.S. (2015) Concerning the maximum frequency limits of Gunn operators. Journal of Terahertz Science and Electronic Information Technology, 13(3), pp. 389-395.

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Abstract

The length of the transit region of a Gunn diode determines the natural frequency at which it operates in fundamental mode-the shorter the device, the higher the frequency of operation. The long-held view on Gunn diode design is that for a functioning device the minimum length of the transit region is about 1.5 μm, limiting the devices to fundamental mode operation at frequencies of roughly 60 GHz. The authors posit that this theoretical restriction is a consequence of limits of the hydrodynamic models by which it was determined. Study of these devices by more advanced Monte Carlo techniques, which simulate the ballistic transport and electron-phonon interactions that govern device behaviour, offers a new lower bound of 0.5 μm, which is already being approached by the experimental evidence shown in planar and vertical devices exhibiting Gunn operation at 0.6 μm and 0.7 μm. It is shown that the limits for Gunn domain operation are determined by the device length required for the transferred electron effect to occur(approximately 0.15 μm, which as demonstrated is largely field independent) and the fundamental size of the domain(approximately 0.3 μm). At this new length, operation in fundamental mode at much higher frequencies becomes possible-the Monte Carlo model used predicts power output at frequencies over 300 GHz. Back

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Cumming, Professor David and Khalid, Dr Ata-ul-Habib
Authors: Macpherson, R.F., Dunn, G.M., Khalid, A.-u.-H., and Cumming, D. R.S.
College/School:College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
Journal Name:Journal of Terahertz Science and Electronic Information Technology
ISSN:2095-4980

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