Advances in Gunn diode technology

A Gunn diode is a simple two terminal source of low-noise, high frequency microwave power, it is most commonly used as local oscillator in critical microwave and mm-wave systems, The system requirement of frequency agility and temperature stability impose stringent demands on the device performance and hence on its material and fabrication technology, The present paper discusses some of the technological innovations attempted in this direction along with results obtained. Some of the issues addressed are carrier concentration ramping to check velocity degradation in the active layer, power optimisation by in-situ etching, minimisation of dead zone and thermal management, Physics, design and fabrication technology and testing of Gunn diodes is also briefly described in this article.