Towards a Reconfigurable Metacavity Antenna for Computational Imaging and DoA Estimation

In this paper, a reconfigurable metacavity antenna (RMA) that can be used for microwave computational imaging (CI) and direction of arrival (DoA) estimation applications is proposed. The RMA is an electrically over-sized metacavity with its back wall replaced by a 1-bit reconfigurable metasurface and its top surface etched with leaky circular irises. By leveraging the frequency-diversity and the dynamic aperture techniques, spatio-temporally low-correlated radiation patterns can be generated by the RMA at different operating frequencies and under different PIN states. The reflection coefficients at operating frequencies are under -10 dB, indicating the RMA is impedance-matched. The correlation coefficients are smaller than 0.3 and the singular values are close to each other, which demonstrates the spatial-orthogonality of the measurement modes. Simulated experiments are implemented to validate the feasibility of the proposed RMA for CI and DoA estimation. Using the developed RMA, the target image has been reconstructed and the far-field source has been estimated. The proposed design is validated through simulations in CST Microwave Studio.