A Cross-Eye Jamming Scheme Based on Microwave Photonics and Its Hardware-in-Loop Performance Investigation

A novel retrodirective cross-eye system based on microwave photonics is proposed. The scheme utilizes a dual-parallel Mach–Zehnder modulator (DPMZM) to modulate the RF signal received at the left (right) end onto the same optical fiber, transmits the optical signal to the right (left) end, and converts the optical signal back into RF signal by a photodetector (PD). By controlling the bias voltage of the main modulator of two DPMZMs, the phase of the transmitted RF signal can be reversed and the amplitude of the transmitted RF signal can be adjusted. The scheme has large working bandwidth and low cost. Only generating two-phase inverted signals is not enough to implement effective cross-eye jamming. It is necessary to consider nonideal conditions and the impact of echoes on jamming in order to obtain practical technical solutions. The scheme exhibits good robustness, as the relative phase of two jamming signals remains insensitive to bias drift. The scheme provides flexibility in controlling the signal amplitude to meet the requirements for angle deception. From the phase-front distortion perspective, an analysis of the impact of cross-eye parameters on the deception angle is conducted. In the experiment, the transfer functions in the 4–27-GHz frequency range are provided. Through hardware-in-loop simulation, the capability of the scheme to effectively deceive the monopulse radar is validated. Discussions and analysis are conducted on the dynamic cross-eye jamming process and the impact of target echoes on the cross-eye jamming performance. Parameter optimization and control strategy for the scheme are investigated with the impact of target echo considered.