A Low-Cost, Quad-Beam, Dual-Polarized, 2-D Leaky Wave Antenna With Wide-Angle Beam Scanning for Millimeter-Wave Applications

A novel low-cost, dual-polarized, 2-D leaky wave antenna (LWA) with four beams is proposed in this article. The proposed 2-D LWA includes a 2-D leaky wave radiation aperture and an orthogonal feeding network. The 2-D leaky wave radiation aperture is evolved from two identical 1-D parallel-plate long-slot LWAs that are orthogonally placed within a shared radiation aperture. Based on the proposed feeding networks, two pairs of orthogonal in-phase excitations are provided for the proposed 2-D radiation aperture to realize four beams with orthogonal polarizations. Combining the frequency-controlled beam-scanning characteristic of the 2-D LWA in the elevation plane and the quad-beam radiation by the proposed feeding network in the azimuth plane, a wide-angle beam-scanning characteristic can be realized. Besides, different from the conventional multibeam antenna with multiple feeding ports or multiple radiation apertures, only a simple coaxial feeding port and single aperture are used, which greatly reduces the complexity and cost of the antenna. A prototype for verifying the design concept is manufactured and measured. The measurement results illustrate that the antenna supports a wide beam-scanning range around ±83° except for broadside direction in two orthogonal elevation planes with orthogonal polarizations. Furthermore, a wide operating bandwidth from 23 to 33.6 GHz with a peak realized gain of 21.2 dBi is obtained by the antenna. The low-profile, quad-beam, dual-polarized, wideband, high-gain, low-cost, and wide-angle beam-scanning features make the proposed antenna suitable for various millimeter-wave applications.