Determination of the optimum connection length between amplifier modules for the most flat transfer characteristics

In design of microwave multi-stage amplifiers composed of N amplifier modules, the large variations in gain and flatness of amplifier as various connection length between modules have been studied. The methods, equations and conditions for the maximum gain or the most flat gain within bandwidth are presented. The sensitivity analysis for the connection length shows that the small changes of the phases of input and output reflection coefficients (S₁₁, S ₁₂) of amplifier module itself are the most important in determination of connection length in order to get the most flat gain