Microwave Waveguide Flanges

A waveguide flange is a waveguide section's connection interface. To ensure minimal losses when connecting two waveguide sections, the flange types must match.
Waveguide flanges can be square or circular in shape.
(Find out more about rectangles and circulars here.)

To keep the connection together, flanges are usually bolted together with four or more bolts. The majority of FT-RF products are designed with a UBR waveguide flange. It has a flat face, which is also referred to as a cover flange (or Plain flange )
It provides the best match performance when mated to another plain or 'O' ring flange, such as PBR.
PBR: has a flat face with an 'O' ring groove cut into it for environmental or pressure sealing.

If the flange is properly aligned and used at the frequency for which the choke was designed (typically the band center), it provides the best leakage performance.
There are two main standard bodies for rectangular waveguide flanges to ensure consistency and compatibility across manufacturers: North American EIA (Electronic Industries Alliance) Waveguide Flange Shapes and IEC (International Electrotechnical Commission) Waveguide Flange Shapes. FT-RF designs and manufactures antennas in accordance with IEC standards.