Wideband patch antenna through introducing co-plane terminal

Wideband operation is a crucial topic in patch structure research. Various wideband methods have been developed for patch antennas. However, some of the key benefits of patch antennas, such as semi-space radiation and easy fabrication, are degraded. In this study, we refer to the planar inverted-F antenna (PIFA) and propose a co-plane terminal loading strategy, resulting in an antenna model termed the co-plane terminal loaded antenna (CTLA). It transforms the dipole-to-background metallic via in PIFA to a dipole-to-feed gap in CTLA. Because the gap is a coupling connection, the impedance-match and resonant-frequency performance improve, resulting in a wider bandwidth. Based on the proposed approach, three CTLAs, including an original CTLA, an improved CTLA, and a multi-path CTLA, were constructed and simulated, with relative bandwidths of 63.5%, 55%, and 62%, respectively. The radiation pattern is typically patch-like, radiating in semi-space, and hybrid polarisation over the working band. Finally, the improved and multi-path CTLAs are fabricated and measured to validate this method and ensure that the results are consistent with the simulation results accurately. This study proposes a terminal-loading method for patch structures, which results in wideband radiation. It can be used in wideband phased arrays, communication systems etc.