The circulator[1] is an analogous component in rf, it send the incident power from any port down to the next port, so you can take one port to be the bidirectio

The circulator[1] is an analogous component in rf, it send the incident power from any port down to the next port, so you can take one port to be the bidirectional connection, and it splits the signal into transmit and receive connections. [1] https://en.wikipedia.org/wiki/Circulator https://en.wikipedia.org/wiki/Circulator