Differential Coincidence Imaging With Frequency Diverse Aperture

A novel coincidence imaging method using the differential of radiation patterns (DRP) generated by a frequency diverse aperture (FDA) is proposed in this letter. The proposed FDA consists of metamaterial structure cells with different resonance frequencies in double layers and a wideband patch antenna. The minimum correlation coefficient criterion of the DRP is used during the location design of metamaterial structure cells. The transmitting and receiving channels at each frequency should be separately calibrated in advance to obtain grouped and balanced DRPs. In addition, the performance of the proposed imaging method is analyzed using one-dimensional model compared with traditional imaging method with FDA and ideal random radar array. Finally, the high-resolution image is reconstructed using an optimization algorithm. The ability of the immunity against interference of the proposed method is much better compared with the traditional imaging method with FDA. The proposed imaging method and the design of the FDA are validated through experiments.