Comments on "Unilateral gain of heterojunction bipolar transistors at microwave frequencies

A general expression for Mason's gain U is derived and expressed in the linear two-port h parameters of a network. In a recent paper by S. Prasad et al. (ibid., vol.35, no.12, 1988, p.2288-94) an incorrect expression for U is presented. The commenter shows that the two expressions are equal at only one frequency, f/sub max/, i.e. when U is solved for U=1.<
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