Design of a Small Controlled Reception Pattern Antenna Array With a Single-Layer Coupled Feed Structure for Enhanced Bore-Sight Gain and a Matching Bandwidth

This article proposes the design of a controlled reception pattern antenna (CRPA) array with a single-layer coupled feed structure to improve the radiation gain and a matching bandwidth. Each array element consists of a feeding patch and an outer radiating loop printed on a thick ceramic substrate with a high dielectric constant. The loop is capacitively coupled to the patch and the coupling strength is adjusted by varying the gap distance. Antenna characteristics are measured in a full anechoic chamber, and an equivalent circuit is built to verify the operating principle. The results demonstrate that the proposed structure is more suitable to enhance the gain and bandwidth compared to a conventional patch antenna in small CRPA arrays.