A Universal Microwave Photonic Receiving Channel

Abstract

Main characteristics of a model of the microwave photonic receiving channel with optical heterodyning have been numerically simulated and experimentally investigated. The transducer is based on a twoarm (signal and reference) balanced circuit with a continuous wave laser, amplitude modulators, narrow-band optical filters, and a photodetector. The possibility of implementation of the receiving channel with a signal-to-noise ratio of up to 60–70 dB, a carrier frequency of up to 40 GHz and more, and a detection bandwidth of up to 1 GHz is demonstrated. It is shown that semiconductor lasers without outer stabilizing cavities can be used in an optical pumping source by means of compensation of the laser frequency noise. It has been found, that if the modulator working point corresponds to the optical carrier frequency suppression mode, the noise characteristics of the detector can be maintained without application of narrow-band optical filters.