Figure 2
From: Multiplexed Millimeter Wave Communication with Dual Orbital Angular Momentum (OAM) Mode Antennas
The 90° hybrid coupler is designed as the feeding network. (a) The schematic of the 90° hybrid coupler with two input ports and two output ports. (b) The waveguide 90° hybrid coupler model to match the structure of the ring resonator shown in the Fig. 1a.
