Frequency modulators for use in microwave links

摘要

Frequency modulators for use in microwave link transmission systems include acoustic surface wave (ASW) oscillators. Each frequency modulator comprises two voltage control quadripole ASW oscillators. Control inputs of the two ASW oscillators receive modulation signal in opposite phase. Outputs of ASW oscillators are mixed in a mixer for delivering an IF signal. Thus frequency deviation is larger than in a conventional arrangement. Moreover, surface wave oscillators make it possible to directly insert a service channel signal in a microwave link repeater, without demodulation and modulation operations.