Microwave Imaging Method Based on Reconfigurable Spatial Dispersion Radiation

Based on a reconfigurable spatial dispersive radiation antenna, a microwave compressive sensing imaging method is proposed in this article. According to theoretical analysis, it cannot improve lateral resolution without reducing range resolution in a traditional dispersion-based microwave imaging system. In this work, the issue is addressed by the proposed tunable traveling wave antenna (T-TWA) and variable spatial dispersion compressed sensing (CS) imaging. The T-TWA realizes mechanical, spatial dispersion radiation reconfiguration within the 6.5-10.5 GHz frequency band while maintaining the radiation surface position fixed. Then, the CS algorithm is applied to implement 2-D imaging and positioning on a 5 mm side length target. Simulation and experiment demonstrate that the proposed system attains a lateral resolution of 2 mm (about 1/20 central wavelength) and a range resolution of 7 mm (about 1/5 central wavelength), exhibiting a tenfold and a fivefold enhancement compared to theoretical, respectively. Compared with the imaging system based on a nonadjustable dispersion antenna, the imaging resolution is improved by more than twice in the lateral direction. The proposed imaging system and the tunable dispersive antenna are applicable in fields like vehicle radar, indoor electromagnetic positioning, etc.