Frequency-diverse bunching metasurface antenna for microwave coincidence imaging

A frequency-diverse bunching metasurface antenna (FDBMA) that can be used for microwave coincidence imaging (MCI) is proposed in this paper. The proposed FDBMA consists of two distinct types of apertures: the bunching aperture and the random aperture. A triple-layer-metal-baffle (TLMB) is designed to partition different apertures and improve the bunching characteristic. The bunching aperture is formed by a seven-element patch antenna array, which generates the bunching beam. Additionally, the random aperture comprises a random modulated metasurface along with twelve evenly distributed patch antennas serving as excitation sources. The random apertures superpose the frequency-diverse random beams on the bunching beam, thereby achieving the low-correlated frequency-diverse bunching radiation patterns. Low-correlated radiation patterns can be used as different measurement modes, which ensures the feasibility of MCI. The proposed FDBMA is verified through full-wave simulations.