A waveguide is a microwave component that can transfer energy from one place to another. A waveguide confines the energy within a hollow metal structure, which greatly reduces transmission losses, rather than radiating energy directly into the entire space like an antenna. Waveguides come in rectangular and circular forms, as well as curved waveguides. Today, let's get to know the magic TEE waveguide.
Magic TEE waveguide is a 180-degree hybrid power splitter with 4 ports made from a single waveguide structure. The magic TEE waveguide emerged during World War II and has existed for over seventy years. The structure of the magic TEE waveguide is formed by the intersection of the E -plane waveguide arm and the H -plane waveguide arm at the junction of the other two collinear ports.
Please note that the magic TEE waveguide does not have a single conventional port assignment, and the port assignments specified by some suppliers or descriptions may differ from those used in this article. Ports 1 and 2 are designated as the two collinear ports, where port 3 is the E -plane port, and port 4 is the H -plane port.
The basic functionalities of the magic TEE waveguide can be divided into three basic scenarios.
Injecting two signals into ports 1 and 2. In this case, the sum of ports 1 and 2 exits through port 4, and the difference exits through port 3.
Injecting a signal into port 4. The signal is equally divided between ports 1 and 2, and port 3 outputs a level of 0.
Injecting a signal into port 3, where equal amplitude but opposite phase signals are incident on ports 1 and 2, the output of port 4 is zero. This behavior is the reason why port 4 is typically designated as the sum port, and port 3 is designated as the difference port.
In some cases, the E -plane port is represented as port 4, the H -plane port is represented as port 1, and the collinear ports are represented as ports 2 and 3, respectively.
Magic TEE waveguide applications are also very wide. Below are the applications of the magic TEE waveguide when used as an impedance measurement tool, duplexer, and mixer.
Impedance measurement: When using the magic TEE waveguide for impedance measurement, you can first connect a zero-value indicator to the E-plane port and a microwave source to the H-plane port, then balance it to form an impedance bridge with the collinear ports.
Duplexer: To use the magic TEE waveguide as a duplexer, you can connect a transmitter and a receiver to its two different collinear ports, the E-plane port to an antenna, and terminate the H-plane port with a matched load.
Mixer: When connecting an antenna to the magic TEE waveguide at the E-plane port, a local oscillator to the H-plane port, terminating one of the collinear ports, and connecting a mixer circuit to the other collinear port, a mixer can be formed between the two collinear ports.