A computer aided procedure for experimental chamcterization and small signal modeling of MESFETs

Abstract

A system which integrates in a single workstation the experimental procedures and data processing in order to carry out small‐signal equivalent circuits of microwave FET is presented. The workstation basic hardware consists of a HP8510 vector network analyzer, a dual programmable power supply, a dc bias switching box and a HP9000 series 300 desktop computer. While other approaches base the extraction of circuit elements mainly from scattering parameter measurements, the developed one implements several types of measurement techniques both in dc (pulsed), and in, necessary to directly extract several circuit parameters. Thus the optimization of a great number of parameters is avoided, which often leads either to an ill conditioned determination of element values, or to extraction of physically meaningless parameters. Furthermore by means of the described procedure several MESFET parameters tied to the technological process can be achieved. Some experimental results obtained with on wafer ion implantated devices show a very good model accuracy reached in the frequency band from 1 GHz to 18 GHz.