Waveguide rotary joint

Waveguide rotary joints are used in radar systems to couple signals to a rotating radar antenna. The RF-signals can be provided to the waveguide rotary joint either by waveguides or coaxial-cables.

Depending on the required number of channels, such as for different antenna diagrams, waveguide rotary joints can have up to nine channels.^[1]

Waveguide rotary joints are used in radar systems at connections between two different types of RF waveguides. The symmetrical shape of the joints allows free rotation without performance degradation. In the rotating part, electrical continuity is achieved by λ/4-chokes eliminating metal contacts. The rotary joints can have both waveguide ports at a right angle to the rotational axis, "U-style", one waveguide port at a right angle and one in line, "L-style" or both waveguide ports in line. "I-style". Waveguide rotary joint modules are available for all frequency bands. ^[2] Common materials for waveguide rotary joints include aluminum, brass, bronze, copper, and silver.^[3]