A Microwave Photonic Ranging Radar Based on an Acousto-Optic Frequency Shifting Loop

A microwave photonic radar ranging system based on an acousto-optic frequency shifting loop (AO-FSL) is demonstrated. The AO-FSL is used to generate periodic and chirp rate tunable linear frequency modulated waveforms (LFMWs). In the experiments, LFMWs with a chirp rate of 492 MHz/ns in a frequency range of 6–16 GHz are generated as probe signal. The echo signal is dis-chirped by photonic frequency mixing. Distance measurements are achieved with a maximum error less than 1.1 cm and a resolution of 1.13 cm in a maximum unambiguous range of 4 m.