Injection Locked Phase Modulator (Correspondence)

This communication describes a novel type of phase modulator based on the injection locking principle. The particular device described utilizes a klystron but the technique is not restricted to the microwave retion of the frequency spectrum. The technique may be applied to any oscillator that has a voltage tuning characteristic. The frequency of most oscillators is somewhat dependent on the voltages applied to various parts of the oscillator circuit and heretofore many techniques have been devised to overcome this effect. The injection locked phase modulator makes use of the voltage tuning effect which may be inherent or induced by inclusion of a voltage variable capacitor, or other device.