A Passive ISAR Modulation Method Based on Time-Modulated Corner Reflectors

The time-modulated corner reflector (TMCR) is an improvement of the traditional corner reflector based on time-modulated metasurfaces, which can manipulate the characteristics of electromagnetic waves in real-time. In this paper, a novel passive ISAR modulation method based on the asynchronous control of TMCRs is proposed, which can directly destroy the ISAR imaging mechanism. Through the joint inter-pulse and intra-pulse periodic modulation, multiple corner reflectors 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. On this basis, the design criterion for inter-pulse modulation mode is described in detail. Finally, experiments are conducted based on the measured data of the UAV, which verifies that the proposed method can effectively interfere with the ISAR imaging.