Input impedance matching of a bipolar transistor employing a coaxial transformer

摘要

A coaxial transformer is employed to provide impedance matching for the input of a bipolar transistor operated in the VHF frequency range. The coaxial transformer comprises a first winding wound around a ferrite toroidal core. The second winding has a single turn and consists of a metal enclosure substantially surrounding the first winding. One end of the first winding is connected to the base of the transistor and the other end of the first winding is connected to ground. One end of the second winding is connected to the emitter of the transistor and the other end of the second winding is connected to ground.