Tunable radar compound coherent jamming signal generation based on microwave photonics

A photonic-assisted scheme to generate radar compound coherent jamming signals based on a dual-parallel Mach-Zehnder modulator (DP-MZM) is proposed and experimentally demonstrated. The received linear frequency-modulated (LFM) signal is interrupted sampled and comb spectrum modulated by a DP-MZM. After photoelectric conversion, the compound coherent jamming signal, which combines the comb spectrum modulation jamming (CSMJ) and interrupted sampling repeater jamming (ISRJ), is generated. In the experiment, the generated coherent jamming signals have a 1-GHz bandwidth centered at 8 GHz and 18 GHz, respectively. The tunability of the frequency interval for CSMJ, the duty cycle, and the sampling frequency for ISRJ are verified. After pulse compression (PC), 10 false target groups are evenly distributed over a radial distance of 120 m, and the total number of false targets reaches to 50. The jamming effectiveness in radar imaging is also demonstrated. To the best of our knowledge, photonic-assisted CSMJ and ISRJ compound jamming generation is proposed for the first time. The proposed scheme is compact, wideband, and tunable, which shows a good potential application in the future electronic warfare system.