Compact Wideband Phase Shifter Using Microstrip Self-Coupled Line and Broadside-Coupled Microstrip/CPW for Multiphase Feed-Network

In this letter, a compact wideband phase shifter using a microstrip self-coupled line and a broadside-coupled microstrip/CPW (BCMC) structure is proposed for multiphase feed-network. With a uniform phase reference, such a phase shifter can achieve multiphase responses by adjusting instinct self-and broadside couplings for constant phase shifts within a wideband. Then, with the combination of proposed phase shifters and a microstrip Wilkinson power divider, a multiphase feed-network can be implemented. To verify the mechanisms mentioned earlier, a wideband feed-network is fabricated with measured multiphase responses (i.e., 0 degrees, 5.625 degrees, 11.25 degrees, 22.5 degrees, 45 degrees, 90 degrees, and 180 degrees) and maximum insertion loss of 1.57 dB from 1.7 to 2.3 GHz.