Radar Target Simulator Based on Swept-Wavelength Optical Source

Radar target simulators (RTSs) play an important role in testing and verifying radar systems. Conventional electronic-based RTSs are not suitable for testing broadband radar systems due to the limited bandwidth. Various photonics-based radar target simulators have been proposed to overcome the issues. However, these schemes cannot simulate Doppler frequency shift accurately while the bandwidth of the radar-under-test (RUT) is large and the simulated target moving fast. To solve these problems, a radar target simulator based on swept-wavelength optical source is proposed in this letter. Incoherent broadband optical source (BOS) and tunable fiber Fabry-Perot filter (FFPF) are used to assemble a swept-wavelength optical source. The RUT’s transmitted signal is modulated to this optical source. Continuously time-varying delay of RTS can be achieved by transmitting the swept-wavelength optical signal through dispersion module. Thus, we can achieve simulation of target motion. In the experiment, the velocity of the simulated target reached 5130 m/s. Moreover, multi-band radar signals can be simultaneously processed.