An alternative approach in deriving associated circle equations for microwave transistor amplifiers

The bilinear transformation is employed in deriving associated circle equations for microwave transistor amplifiers in the conjugately characteristic-impedance transmission line (CCITL) system. This approach is engaged in transforming stability, operating and available power gains, voltage standing wave ratio (VSWR), and noise circles located in the reflection-coefficient plane (Gamma-plane) in the Z
₀
system into the corresponding ones in the CCITL system at any argument phi, which is the argument of the CCITL characteristic impedances. Its validity is verified by comparing with result of the characteristic conductance (CC) approach. Its convenience over the CC approach is realized.