Omnidirectional Solid Angle Beam-Switching Flexible Array Antenna in Millimeter Wave for 5G Micro Base Station Applications

This study proposes a cylindrical conformal array antenna (CCAA) for fifth-generation (5G) micro base station applications. The CCAA is composed of five Chebyshev flexible linear array antennas (LAAs) with a circumferentially uniform arrangement on the cylindrical surface. The LAA with a logarithmic periodic arrangement is constructed by synthesizing the current amplitude distribution coefficients in elements with the Chebyshev method. The LAA with a half-power bandwidth (HPBW) wider than 76° (-8.41° to 38.58°) and a peak gain greater than 10 dBi is fabricated via the micro-electromechanical system process. Cost-performance analysis shows that five is the best number of linear arrays. To achieve omnidirectional switching scanning of the circumferential section, five LAAs wrapped on the cylindrical surface are individually excited by connecting a radio frequency semiconductor switch to the exciting ports of an eight-way power divider. Moreover, beam-switch scanning of the CCAA is measured with the aid of a standard anechoic chamber. The irradiated performance with low mutual coupling and high realized gain is verified to be irrelevant to the structural variation of various flexible experiments of LAAs wrapped around a cylindrical surface. The CCAA with beam-switch scanning operates at 26 GHz and belongs to the 5G millimeter-wave band. Results show the proposed antenna achieves omnidirectional scanning property in the H plane and has a HPBW of only 9.08° in the E plane. The performances of the CCAA present potential advantage in flexible terminal equipment wireless communication.