ABSTRACT
This chapter presents additional topics related to the design of power amplifiers. The amplifier can be driven to a large signal level representative of normal operation. The tuner can be adjusted to minimize the input reflected power as measured on the network analyzer. Most linear power amps will behave like a small signal amplifier. S-parameter simulation may be useful as a starting point for estimating input impedance. Input source pull simulation templates are also provided in the amplifier design guide. All the elements with arrows are dependent on input and output voltages and currents. Impedance levels are often lower, much lower, in power amplifiers. High current transients are beyond what a Direct current regulated supply can provide. A more complicated decoupling system is required for power amplifiers to avoid resonances and oscillation. The trick is to do this without losing power or efficiency. A wideband spectral display is also needed to reveal out-of-band low or high frequency instabilities.
