Theory of gain and stability of small-signal amplifiers with lossless reciprocal feedback

The gain and the stability of composite amplifiers consisting of a core 2-port amplifier and a lossless reciprocal embedding network is studied theoretically with particular interest in the design of near-f
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amplifiers. Design equations for finding an optimal embedding network that gives the highest MAG (maximum available gain) under a given stability requirement are presented. How such an embedding network could be synthesized is briefly sketched.