What type of duplexer acts like a revolving door for RF energy?

A ferrite circulator is a non-reciprocal device that allows RF energy to flow in one direction while preventing it from flowing in the opposite direction, making it ideal for separating incoming and outgoing signals in a radar system. This characteristic can be likened to a revolving door, where entry and exit are limited to specific pathways. In the context of radar systems, the circulator directs transmit signals from the transmitter to the antenna and incoming signals from the antenna back to the receiver without interference. This function is crucial for effective frequency usage, maintaining signal integrity, and enhancing overall radar performance. Understanding the circulator's role is vital in the design and operation of pulse radar systems.