Extraction of π -Capacitor Equivalent Circuit Elements for Field-Effect Transistors in Deep Pinch-Off

A heterojunction field-effect transistor in blocking (deep pinch-off) connected between two transmission lines (gate to drain) is represented as an asymmetric transmission-line gap. This configuration allows one to determine the $\pi$ -capacitor equivalent network from $S_{12}(\omega)$ or $s_{21}(\omega)$ measurements only. We discuss the method of extracting equiv...