A novel broadband 3 × 4 Butler matrix beamforming network without crossovers

Abstract

AbstractA novel broadband three‐input four‐output (3 × 4) Butler matrix (BM) without crossover is presented for the wider band operation. The proposed 3 × 4 BM is composed of three 3 dB branch‐line directional couplers, one T‐splitter power divider, and two 90° phase shifters. Unlike the traditional BM, the proposed BM network has successfully eliminated the crossover connection for simplifying the network, which operates in a wide operating range. For the validation of the design, a planar single‐layer 3 × 4 BM working at the frequency band of 1.69–2.69 GHz is designed, fabricated, and measured. The measurement result gives bandwidth up to 46% with return loss better than 14.3 dB at the full operating frequency band.