A Low-Cost Polarization Detection Approach Enabled by Energy Harvesting Metasurface: Concept, Design, and Experiment

A low-cost and low-complexity polarization detection approach is proposed to estimate the polarization angle of linearly polarized (LP) incident electromagnetic (EM) waves using polarization-sensitive energy harvesting metasurfaces (EHMs). Two identical EHMs are proposed to be deployed on the same receiving plane with orthogonal orientations, which can separately capture the two orthogonal electric-field components of the incident wave and further convert them into alternating-current (ac) signals. The two captured ac signals are then rectified into two direct-current (dc) voltages that can be measured and used to estimate the polarization state. A polarization-detection voltage ratio (PDVR) parameter is introduced to characterize the polarization angle versus the two output dc voltages in a monotonic linear manner, providing a high-accuracy polarization angle detection. To demonstrate the proposed scheme, a polarization-sensitive EHM composed of $8\times8$ unit cells together with a single-stage voltage multiplier rectifier is designed, fabricated, and measured in the 5.8-GHz band. The measured results show that the maximum energy harvesting efficiency of the proposed EHM is 82.1% at 5.8 GHz, and the output dc voltage from the rectifier circuit is 0.927 V with an optimal input power of 5 dBm. A polarization-angle error of less than 2.3° is achieved during the polarization detection experiment, where no complicated and costly radio frequency (RF) component or circuit is used. The proposed approach has features of low cost, low complexity, and high accuracy, which is promising for noncooperative radiating source sensing applications.