Figure 1 from Multilayer 180$^{\circ}$ Coupled Line Hybrid Coupler | Semantic Scholar
Figure 1 from Compact and power-efficient 5 GHz full-duplex design utilizing the 180° ring hybrid coupler | Semantic Scholar
Hybrid Coupler Basics — MECA Electronics, Inc.
Difference between 90 degree hybrid and 180 degree hybrid
Hot Selling High Frequency 6-18GHz 180 Degree Hybrid Coupler with SMA-K Connector High Bandwidth RF Hybrid Coupler Widely Used for Base Station - China Microwave Components, Passive Components | Made-in-China.com