Planar Endfire Multibeam Antenna Implementation for Millimeter Wave 5G Applications using a Passive Beam Switching Network

Multibeam antenna implementation is necessary for millimeter wave (mmW) 5G applications to overcome the attenuation losses effects at these high frequencies, and to improve the spatial coverage using spatial multiplexing. In this work, a single layered, planar, endfire, and linear antenna array of four elements has been designed, which is fed by a 4X4 Butler matrix based beam switching circuit to produce spatially distributed beams. This antenna system that is implemented using transmission lines has a total dimensions of 58.6 mm X 37.7 mm. Four beams produced using the proposed antenna system are spatially distributed with one beam each in 69°, 84°, 97.5° and 112° directions. Peak gain of 13 dBi, side lobe levels of -7.3 dB, and total efficiency of 95% have been achieved with the proposed design that has a wide impedance bandwidth ranging from 26.5 GHz to 30.5 GHz. These values of radiation parameters make this multibeam antenna ideal for mmW 5G implementation.