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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.

In this paper, a photonic approach for the generation of wideband radar jamming signal with flexible tunability is proposed and experimentally verified. In the experiment, interrupted-sampling jamming, comb spectrum modulation jamming, and compound jamming is established upon the received radar signal, respectively. The jamming effectiveness is evaluated through cross-correlating the radar jamming signal with the received radar signal. The cross-correlation results show that variable number of false targets can be generated based on our proposed scheme and the number of the false targets can reach 40. It is worth to note that our approach solves the issue of power loss in traditional interrupted-sampling jamming. Meanwhile, the low-frequency jamming seed signal used in the experiment is quite easy to obtain in electrical domain. The proposed scheme has a stable, compact, and efficient structure, which meets the requirements of the electronic warfare systems and will get potential applications in future electronic warfare systems.

In this article, a wideband radar jamming signal generator with flexible tunability and multidimensional optimization is proposed based on a dual-polarization Mach–Zehnder modulator (DPol-MZM) cascaded with a phase modulator (PM). Interrupted-sampling jamming is achieved with a sampling frequency of 1 MHz and duty cycles of 50% and 25%. Cross-cosinusoidal phase-modulated jamming with frequencies of 2 and 4 MHz is also built. A compound jamming signal that combines interrupted-sampling jamming and cross-cosinusoidal phase-modulated jamming is generated. The jamming effectiveness of the above schemes is evaluated, and multiple false targets are obtained after cross correlation with the original radar signal. The number of generated false targets can reach 12. The jamming mechanism of the proposed scheme is discussed, and the jamming effectiveness in radar imaging is also analyzed. The proposed scheme has a stable, compact, and efficient structure and meets the requirements of the electronic warfare system, which will get potential applications in future electronic warfare systems.

We proposed a system that simultaneously supports measuring the frequency and the angle of arrival (AOA) of the radio frequency (RF) signal. In the proposed system, the RF signals from different antennas are loaded on different arms of a dual-polarization Mach-Zehnder modulator (Dpol-MZM) and are subsampled by dual optical combs, respectively. The frequency of the receiving RF signal can be obtained from two intermediate frequencies (IF), and AOA can be obtained from the phase difference between the upper- and lower-channel IF signals. In the experiment, 0.5–40 GHz frequency measurement range with an error of ±0.06 MHz and ±180 phase shift measurement range with an error of 1.8 can be achieved based on a low-frequency electronic analog-to-digital converter (ADC). The processing of both broadband signal and multitone signal and the system stability are also verified.

In this article, a photonic approach for the generation of switchable multiformat chirp signals with immunity to power fading by simply adjusting the bias voltages of a dual-polarization binary phase-shift keying (DP-BPSK) modulator is proposed. A parabolic waveform signal with $N$ times split is employed to increase the time bandwidth product (TBWP) of the generated chirp signal by $N$ times. A proof-of-concept experiment is established to verify the feasibility of the proposed scheme. Major characteristics of the signal are verified, such as format switching capability, frequency tunability, immunity to power fading, and pulse compression performance. The relationship between unwanted frequency components and the amplitude of the split parabolic waveform signal is analyzed by simulation. The maximum bandwidth of the generated chirp signal is also given.