Printed Dual Layer Three Way Directional Coupler Utilized as 3×3 Beamforming Net

We present a novel printed dual-layer three-way directional coupler, which can be utilized as 3×3 beamforming network (BFN) to provide orthogonal three-beam switching capability. The three-way directional coupler is a passive component with six input/output ports. The signal injected into the input port is equally distributed into the three output ports, with a constant phase difference of -120 o , 0 o , or +120 o . Simulation and measurement results show that within 7% relative bandwidth, good