Metamaterial Iris-Based Cavity Antenna for mm-Wave Computational Polarimetric Imaging

The performance of a scalar computational imaging system is inherently influenced by the target's geometrical features. Nevertheless, leveraging the polarimetric information enables robust target image reconstruction, which can overcome the limitations imposed by varying geometrical features. In this letter, a metamaterial iris-based cavity antenna (MCA) that can generate dual-polarized spatially-random illuminating patterns from 75 to 110 GHz is proposed. The developed MCA is composed of a square cavity with irregular boundaries and a lid etched with sparsely distributed elliptical metamaterial irises. The generated patterns exhibit dual-polarized characteristics and maintain low correlations across varying frequencies, making them suitable to be used as measurement modes in a computational polarimetric imaging system. The performance of the designed MCA is evaluated through full-wave simulations and measurements. Finally, a prototype of the MCA is fabricated and experimentally validated within the frequency band of 75–110 GHz.