A Single Metasurface Can Perform Range‐Velocity Detection and Target Imaging Simultaneously at Single Frequency

Abstract

Abstract Range, velocity, and geometric shape are primary features of a moving target. Obtaining these features usually needs high‐cost system and complicated signal processing. Here, a single‐frequency mechanism to detect these features simultaneously with digital programmable metasurface (DPM) in transmission type is proposed. For range‐velocity detection, the DPM can produce sum beams whose radiation phases are modulated by sequentially changing aperture codes of the metasurface to generate biphase coded signals, in which the Range‐Doppler algorithm is used to estimate the range and velocity information of a moving target. Then difference beams are generated by the metasurface, and the sum‐difference ratios of echo signals are used to locate the target. For two‐dimensional imaging, random radiation patterns are produced by the DPM, and the matched filtering algorithm is used to image the target. Since the proposed mechanism implements all detections based on a single programmable metasurface, the complexity and cost of detection systems are greatly reduced, showing promising potentials of DPMs in intelligent and universal electromagnetic sensing.