Importance

Loading Importance Indicators...

Abstract

Automatic impedance matching apparatus in which a matching unit is connected between a radio frequency source and a load and which comprises variable capacitors and inductor, the capacitors being varied by stepping motors to match the impedance presented to the source to the impedance of the source. The stepping motors are controlled by a circuit which generates trains of pulses corresponding to the forward wave voltage and the reflected wave voltage on a line between the source and the matching unit and provides a train of pulses corresponding to the ratio of the voltages. The pulse rates of trains of pulses corresponding to the ratio, before and after a capacitor is varied, are compared, and the sign of the difference between the pulse rates is used to select a motor and step it in the direction which will cause the variable capacitor connected thereto to change its reactance in a direction which will increase the ratio between the forward and reflected wave voltages.

Loading the Abstract Image...

First Claim