Planar antennas for far-field beam steering at end-fire using directive surface-wave launchers

Abstract

Planar antennas that achieve end-fire radiation by surface-wave (SW) edge diffraction are investigated. Specifically, Yagi-Uda like directive surface-wave launchers (SWLs) are utilized as the surface-wave antenna (SWA) feed, exciting cylindrical SWs on a grounded dielectric slab (GDS). With the design of a recessed ground plane, suitable conditions are achieved for far-field radiation at end-fire. In addition, a novel SWA offering end-fire beam steering is also presented by using a two element array of SWLs. Measured results suggest that the radiated beam pattern can be steered by 8° from φ = −4° to φ = +4° in the far-field. In addition, highly directive beam patterns are observed from 18.5 – 22.7 GHz suggesting a relatively large radiating bandwidth. To the authors knowledge this is the first time such planar SWAs have been fabricated and measured.