A Passive ISAR Jamming Method Based on Time-Modulated Corner Reflectors Under Asynchronous Control

The time-modulated corner reflector (TMCR) is an improvement of the traditional corner reflector utilizing time-modulated metasurfaces, which demonstrates superior capability in dynamically modulating characteristics of electromagnetic waves in real-time. Despite its potential, the application of TMCRs in radar imaging remains underexplored. This paper presents a passive ISAR modulation method through the asynchronous control of TMCRs, which can directly disrupt the ISAR imaging mechanism. Through the joint inter-pulse and intra-pulse periodic modulation, multiple TMCRs are alternately switched between strong and weak reflection states asynchronously, which can interfere with the alignment process of range profiles and further causing errors in initial phase compensation. The intra-pulse modulation model is constructed firstly, and the influence of TMCR and modulation parameters on the envelope correlation is investigated quantitatively. On this basis, the optimization model of inter-pulse modulation is developed, which is calculated through Genetic Algorithm (GA). Then the effectiveness of the method is systematically analyzed under varying application parameters, with corresponding applicable boundaries subsequently determined. Finally, experiments are conducted based on the electromagnetic simulation data and measured data of the UAV, which verifies that the proposed method can effectively interfere with the envelop alignment and phase compensation processes, thereby making the ISAR image blurred.