Surface Wave Launcher Based Multi-beam Antenna for 5G Applications

Abstract

Two-dimensional (2-D) planar ‘bull-eye’ Leaky-wave Antennas (LWAs), and other similar configurations have gained considerable interest over the years due to their compatibility with planar technologies and ease of fabrication. Planar Surface Wave Launcher (SWL) Based feeding (slot configurations) in the ground plane of a single layer grounded dielectric slab have been recognized as an efficient means to realize these antennas as a slot in a ground plane has an electric field that can match with the dominant mode of the slab. These antennas when used along with Partially Reflecting Surface (PRS) can excite leaky waves in both the uni-directional and bi-directional directions. These properties allow them to be beneficial for use in various applications where directive beams are required. These include the low profile and low-cost surveillance systems, radars, and 5G systems. An important requirement of 5G systems is to have antennas with multi-beam capabilities in the millimeter-wave band. This provides the impetus for a new breed of antenna design. This work introduces a new technique of utilizing the SWL Based LWAs, wherein uni-directional SWL array elements are employed as antenna feeds along with a common PRS resulting in a 2-D planar multi-beam leaky-wave structure. Two independent antenna designs consisting of a four SWL element array each, are designed (for specified frequency ranges in the K and Ka bands) with each design generating four distinct beams (tilt angle of ±10o and ±57o ) with 3 dB beam widths of (14o and 16.02o ) respectively, in two separate planes (xz and yz) for the validation of this method. Both designs comprise a similar configuration where the identical antenna elements are placed perpendicular to the next adjacent element. The gains of individual antennas of both designs are 9 dB and 8.5 dB respectively. The presented leaky-wave antennas may be useful in 5G base stations and access point applications where multi-beam antenna systems are required