Enhancing microwave metamaterial aperture radar imaging with rotation synthesis

摘要

Microwave metamaterial aperture imaging radar (MMAIR) is capable of generating high resolution images without using mechanical scanning or antenna arrays. In MMAIR, metamaterial elements are specifically embeded into a parallel plate waveguide, whose resonance frequencies vary among a wide bandwidth. Different radiation fields are gained by wide-band waveforms, and the scene information are measured by measurement matrix which consists of a set of radiation modes. According to the Compressed Sensing theory, MMAIR performance is restricted by the limited frequency measurement modes. Herein we propose a rotation-synthesis approach to synthesize radiation measurement modes. By rotating the metamaterial aperture panel around the panel axis, the approach exploits the radiation field's multi-beam spatial diversity, and with the azimuth rotation, the radiation field pattern varies relative to the scene under the radiation field. As a result, significant MMAIR imaging enhancement is achieved with the crucial increase of radiation measurement modes. The simulations verify the effectiveness and image improvement of the proposed method.