On the Latitude of Choice of Tuned Amplifier Terminations

Analytical expressions exist for the optimum resistive terminations leading to maximum power gain in a tuned mismatched amplifier of specified stability. To satisfy other performance requirements, however, terminations differing somewhat from the optimum may be more suitable, and it is of interest to know how closely the optimum terminations must be approached in order for the gain not to fall drastically from its maximum possible value. In this paper an expression is derived for the power gain obtained with a given degree of stability but with general terminations, and the maximum recommended deviation from optimum terminations is expressed very simply. The results of the investigation are discussed and illustrated with special reference to transistor amplifiers.