Dual-polarized reconfigurable metacavity transceiver for computational polarimetric imaging

In this paper, a dual-polarized reconfigurable meta-cavity transceiver (DRMT) that can be applied in computational polarimetric imaging (CPI) is proposed. The transmitter and the receiver of a CPI system are replaced by two ports of the DRMT, which significantly simplifies the hardware architecture. The DRMT is an electrically over-sized metacavity with its back wall replaced by a reconfigurable metasurface (i.e., PIN diode loaded metasurface) and its top surface etched with leaky cross-shaped irises. By altering the PIN state of each metamaterial element, spatially orthogonal measurement modes can be obtained. Furthermore, due to the polarization-independence of the cross-shaped iris, measurement modes under different polarization states are also orthogonal to each other. In addition, the proposed DRMT exhibits a broadband operational characteristic, facilitating its application in different scenarios. The reflection coefficients under different PIN states are under -10 dB, indicating that the two ports of the DRMT are impedance-matched. The mutual coupling coefficients are under -30 dB, demonstrating good isolation between the ports. The correlation coefficients are smaller than 0.2 and the singular values are close to each other, which proves the spatial-orthogonality of the mea-surement modes. The DRMT-based full-wave CPI simulations are also implemented and polarimetric images were reconstructed using different polarization components to showcase the benefits of the CPI method.