A scanning beam antenna fed by a 7 × 8 Butler matrix for 5G applications

Abstract

A 7 Â 8 Butler matrix (BM) beam-forming network operating at Ka-band is proposed to feed a 8 Â 8 slot array. By merging the two central input ports of the BM into one port, the BM can provide output signals with equal phase, thereby generating a boresight beam. Measured results show that the proposed antenna has impedance bandwidth of 29.5-30.5 GHz, while the gain lies in the range of 14.7-21.8 dBi. Seven beams are realized, including a boresight beam, covering the range from À58 to 58 . In order to verify this concept, the feeding network and antenna are designed and manufactured. The measured results are in good agreement with simulation. It is a capable candidate for 5G mobile terminal applications.