Three-Dimensional Computational Polarimetric Imaging with a Hyperuniform Frequency-Diverse Metacavity Transceiver

Polarimetric information is beneficial for enhancing the imaging quality of computational imaging (CI) systems. However, the hardware that can extract the polarimetric information in a computational polarimetric imaging (CPI) system remains heavily unstudied. Thus, in this article, a hyperuniform frequency-diverse metacavity transceiver (HFDMT) that is capable of retrieving the polarimetric information throughout the K-band is proposed. The proposed HFDMT is a metacavity etched with cross-shaped irises arranged in a hyperuniform distribution. The transmitter (Tx) and the receiver (Rx) of a conventional CPI system are replaced by two isolated ports of the HFDMT, which significantly simplifies the hardware architecture. First, to satisfy the requirements for extracting the polarimetric information while sustaining the high efficiency and frequency diversity, the cross-shaped iris is proposed. The cross-shaped iris working efficiently and independently under two orthogonal polarizations also exhibits frequency-diverse radiation responses. Moreover, to improve the spatial-orthogonality of the measurement modes, the hyperuniform distribution is adopted to arrange the irises. Using the hyperuniform distribution results in up to 33% increase in the number of useful measurement modes under different signal-to-noise ratios (SNRs), as compared to the uniform distribution. Then, the performance of the HFDMT is evaluated. The S-parameters demonstrate that the HFDMT exhibits good impedance match and high port isolation characteristics. In total, 600 measurement modes with correlation coefficients (CCs) lower than 0.35 are obtained from 18 to 26 GHz. Finally, a prototype is fabricated. The 3-D CPI feasibility using the proposed HFDMT is verified by both full-wave simulations and measurements.