A Technique for Predicting Large Signal Performance of a GaAs MESFET

Abstract

Abstmct-A method is dessribed for accurately predicting the nonffnesr microwave perforrnrmse of GaAs MESFET devices. The method utifffes time-domain anafysis and is based upon the experimentally characterized bias dependence of deviecircuit model elements. Precise predictions are made of fundamental and harmonic power levels up to 6 dB of gain compression. I.

Tunable Active Microwave Bandpass Filters Using Three-Terminal MESFET Varactors

“…When the drain-source current is saturated, the active channel capacitance which comes from the charge accumulation effect increases monotonically as Vds increases. This phenomenon was first reported by Engelmann and Liechti [9] and was elaborated by Willing Ot al [8].…”

Large Signal Modeling and Analysis of GaAs MESFET

“…In this model a constant Cds value is assumed. Willing, et al [7], has stated this approximation is valid at least in the saturation region.…”

“…exhibit strong bias dependency [7]. These elements are considered as A Hughes' PF-6000 GaAs MESFET is chosen to be analyzed.…”

Matching of GaAs power FETs using a large-signal modelling technique

“…To achieve this requires additional knowledge of how these elements behave as a function of bias. This has generally been done on a semi-empirical basis, where mathematical forms are chosen which reflect the general behaviour as observed in other works [8] and, where appropriate, are also guided by physical theory. Whatever the origin, an adequate number of fitting parameters are required to enable these expressions to be matched to the data of Table 1.…”

“…We use the method to design matching circuits for the Plessey 4820 Power FET and report good agreement between the predicted output power and gain and that measured from the fabricated modules. Both narrow-band (7.9-8.4 Ghz) and wide-band (7)(8)(9)(10)(11) units have been designed and practical measurements completed on the narrow-band modules.…”