New Topology of 8 x 8 compact single-layer butler matrix without crossovers for multibeam array antenna

A novel compact $8\mathrm{x}8$ Butler matrix using only microstrip couplers and a phase shifter is proposed in this paper Compared with the conventional Butler matrix, the proposed one avoids the interconnecting mismatch loss and imbalanced amplitude introduced by phase shifters. Simulations were carried out with Momentum-ADS software to examine the performance of the proposed design operating at 10 GHz. It is shown that the topology can produce high-quality orthogonal beams with fewer components than traditional Butler matrices. These results validate our design approach.