The 6th generation (6G) mobile networks envision a fully connected world, indicating that next -generation information systems will feature enhanced bandwidth, increased access points, improved energy efficiency, and sophisticated functionalities. The evolution of 6G technologies presents unprecedented challenges to modern electronic warfare. Advanced anti-jamming radar detection techniques, utilizing higher frequency bands and sophisticated modulation methods, substantially enhance information rates and capacities. However, these advancements render traditional jamming techniques based on electronic hardware ineffective due to bandwidth limitations. For instance, digital radio frequency (RF) memory (DRFM) technologies are constrained by digital-analog conversion /digital-analog conversion (DAC/ADC) sampling rates, with instantaneous bandwidths rarely exceeding 2 GHz. Microwave photonics has emerged as a solution to overcome these electronic limitations, garnering significant attention from academia and industry. Unlike conventional microwave systems focused on advancing singular communication or sensing technologies, microwave photonics, characterized by high frequency, broad bandwidth, low loss, and tunability, enables multifunctionality and compact structure. To address the convergence of large-capacity communication, radar detection, and electronic jamming in the 6G context, we present a communication-jamming functionally integrated microwave photonic RF front-end based on a single optical modulator.

In this paper, we proposed a novel communication-jamming functionally integrated microwave photonic RF front-end. The suggested scheme utilizes a dual-polarization optical in-phase and quadrature (IQ) modulator, where the intercepted enemy radar signal or communication signal is modulated on the X-polarization of the carrier via IQM-X, biased at the linear operation point to achieve carrier suppression single-sideband (CS-SSB) modulation. Simultaneously, an RF signal for carrier reconstruction is modulated on the Y-polarization of the carrier via IQM-Y to generate velocity deception information. The IQM-Y bias is adaptively controlled using a self-developed modulator bias control module, enabling transitions between single-false-target, multi-false-target, and blinking-false-target configurations. The dual-polarization optical IQ modulator output signal undergoes polarization alignment before entering a photonic RF memory (PRFM) structure based on an active fiber loop for cyclic storage, generating range deception information and expanding transmission capacity. The stored signal is subsequently detected by a photodetector (PD) to obtain the reconstructed communication signal or range-velocity compound jamming signal.

In experiments, the high-fidelity storage capacity for a 12 GHz RF signal has reached 600 μs in a 300 m fiber optic loop, corresponding to 400 false targets in the range dimension (Table 1 and Fig. 2). Further, the optical carrier is reconfigured by the self-developed bias control module to achieve the integration and switching of single-false-target, multi-false-target, and blinking-false-target jamming functions. (Fig. 3). In multi-false-target generation, the number of false targets within the 10 dB effective bandwidth is kept at 9, ensuring that the total number of false targets during storage reached 3600 (400×9), each carrying different range-velocity deception information. Additionally, by simply adjusting the frequency of the reconstruction signal, fast tuning of the velocity deception can be achieved. On the other hand, the communication transmission for a 16QAM signal with 0.8 Gbaud bandwidth at 12 GHz is also verified. The transmission distance has increased to 90 km, and more than 300 information copies have been generated within a 6.17% error vector magnitude (EVM) penalty (Figs. 4 and 5).

The research findings demonstrate the exceptional storage, jamming, and transmission capabilities of the proposed scheme. The X/Ku band storage capacity achieved 600 μs with 3600 range-velocity compound false targets, while the communication transmission distance extended to 90 km. The solution requires only a dual-polarization optical IQ modulator, utilizing IQM-X for radar or communication signal loading and IQM-Y for carrier reconstruction to achieve velocity deception. The integration of PRFM enables range deception and enhanced transmission capacity. This scheme presents a viable alternative to traditional DRFM, offering a promising solution for future electronic warfare applications.