An Open Cavity Leaky-Wave Antenna With Vertical-Polarization Endfire Radiation

This communication presents an all-metal high-gain vertical polarization (VP) leaky-wave antenna (LWA) with exact endfire radiation. The antenna is composed of ten periodic-arranged open cavity elements coupling fed by double-sided parallel-strip lines (DSPSLs). Different from the conventional LWA with frequency-scanning performance, the endfire beam of the proposed antenna is fixed due to the nondispersion property of the air-filled TEM LWA. Moreover, the array characteristic of the proposed TEM LWA is investigated to suppress the unwanted grating lobe with a suitable period. In order to validate the performance of the proposed antenna, a prototype was fabricated and tested. Because of the mutual coupling between every radiation element, the electric field distribution along the array is uniform, contributing to a high endfire gain of 13.6 dBi within a short array length of 2.9λ
₀
. Furthermore, the extension ability is validated to achieve a higher endfire gain when expanding the array length. Consequently, the proposed LWA is a good candidate for the planar high-gain VP endfire antenna.