Observation of turn-on action in a gate-triggered thyristor using a new microwave technique

The turn-on action by the p-base and n-emitter gates in a thyristor was studied by a new microwave technique. The initial conducting area, the lateral distribution of gate current flowing through the junction, and the time variation of excess carrier density injected into the n-base by the gate current were determined by measuring the reflection of microwave energy, vertically incident upon a small area (0.2 × 0.2 mm²) of the n-emitter layer. The new microwave technique has proved to be useful in designing new gate structures and in studying the operation of new devices.