A 2 × 3 Hybrid Substrate Integrated Waveguide Coupler Applied to Beamforming Network

A 2 × 3 substrate integrated waveguide (SIW) H-plane hybrid coupler operating at 28 GHz with constant phase shifting outputs is proposed. This proposed 6-port hybrid junction coupler can equally divide the input power into the three output ports, with a constant relative phase difference +120°, 0°, -120°. Simulation results indicate that within 5% relative bandwidth, our designs achieve a good impedance matching with high isolation, and equal power division having constant phase shifting.