Nonlinear design procedures for single-frequency and broad-band GaAs MESFET power amplifiers

The design and optimization of MESFET power amplifiers are investigated using an intermediate-level (functional) device modeling approach. The approximations involved are discussed, together with considerations of required circuit terminations at harmonic frequencies. Three variations of the approach, based on large-signal admittance, scattering, and hybrid parameters, are compared in the design of a single-frequency amplifier, and the method is extended to broadband power amplifier design. In all cases, results are validated by comparison with a full time-domain large-signal amplifier analysis, involving realistic, distributed external circuits. >