Multistage Power Amplifiers

This chapter proposes to design multistage power amplifiers, based on the real frequency technique (RFT) and the use of large-signal scattering parameter data generated from a few reference points. The optimization of added power usually used in oscillator design is found to be well suited for power amplifier design because their nonlinear properties have a common nature and common description. The chapter provides the new formulas for the multistage transducer power gain when starting from the load. In the classic RFT technique, the input and output voltage standing wave ratio (VSWR) were computed using a stage-by-stage approach that started from the source. The chapter provides the new formulas for the multistage input and output VSWR when starting from the load. The optimization algorithm is used to define polynomial coefficients of an equalizer that minimize a least mean square error function that includes desired target functions with different weight factors.