This work provides a comprehensive discussion of the bias dependence of equivalent circuit parameters for the three devices and an extensive discussion of temperature dependence. It: covers recess-etched MESFETs and self-aligned MESFETs with and without lightly-doped-drains and JFETs; analyzes GaAs-based pHEMTS and InP lattice-matched HEMT equivalent circuits; and describes a large-signal, temperature-dependent model extractor for A1GaAs-GaAs HBTs. The book is intended for circuit designers, process and device developers and test engineers.