Compressive DoA estimation based on a reconfigurable metacavity antenna with selected measurement modes

In this paper, we present a compressive direction-of-arrival (DoA) estimation technique using a single-port reconfigurable metacavity antenna (RMA) with selected measurement modes. The RMA is an electrically over-sized metacavity with its back wall replaced by an 1-bit reconfigurable metasurface and its top surface etched with leaky cross-shaped irises. By manipulating the on/off states of the PIN diodes loaded on the metasurface, the excitations to the leaky cross-shaped irises are altered, resulting in spatio-temporally random radiated fields that can serve as measurement modes in compressive DoA estimation. The physical layer compression achieved by the RMA substantially reduces the number of channels required for DoA estimation. Simulated experiments are conducted to validate the feasibility of the proposed RMA-based compressive DoA estimation method with three far-field sources. Additionally, a comparison experiment using both the selected and randomly generated measurement modes is conducted. It is demonstrated that employing the measurement mode selection method can significantly improve the DoA estimation accuracy without sacrificing the efficiency.