Leaky-Wave Sectorial Antennas for Passive 2-D DoA Applications

A fully metallic sectorial leaky-wave antenna (LWA) is proposed to perform passive 2-D direction-of-arrival (DoA) estimation. The LWA consists of a sectorial waveguide with periodic corrugations on the bottom plate and periodic slots on the top plate. The frequency dispersion of the waveguide is enhanced with a suitable choice of the geometric parameters of the corrugations using an analytical model. Two different corrugation shapes are selected: concentric and straight corrugations. The former one produces an isotropic dispersion, while the latter one produces an anisotropic dispersion of the aperture field when slots are etched to open the structure. In the open structure, the sectorial geometry and the circular slots allow for a 2-D directional pattern in both azimuth and elevation, and straight corrugations lead to a stronger azimuth-dependent radiation pattern within the field of view. The performance of the LWAs for 2-D DoA estimation are evaluated using the multiple signal classification (MUSIC) algorithm. Results show that an anisotropic design of the corrugations enables a correct DoA estimation of both elevation and azimuth angles with a single-port antenna and with a fully passive system, being much more cost- and power-effective than traditional phased arrays.