A Novel Compact Dual-Band Butler Matrix Design

A compact dual-band 4 X 4 butler matrix is presented for multi-beam antenna consisting of dual-band coupler and phase shifter. The network is realized on a single substrate without any crossovers. Within the working frequency range, the butler matrix exhibits good couplings of between -7.6 and -6.2 dB, and the progressive phase between antenna ports can create four radiation beams at 2.45GHz and 5.8GHz.