Generalized Modeling of GaAs Mesfets and Modfets Based on Highly Accurate Broadband Measurements

A recently defined THLR method for vector network analyzer calibration is used to extract the error-parameters of coax to microstrip transitions with an accuracy hitherto unattained. The scattering coefficients of GaAs FETs such as MESFETs and MODFETs, installed in hybrid technology, are measured and error-corrected up to 40 GHz. A new parameter extraction method is discussed to get reliable bias-dependent model parameters. These are represented in 3D graphs covering the gate-forward, pinch-off, saturation, and non-saturation region as well. Thus analogue and digital operations can be described.