Radio Frequency (RF) & Wireless Design

I wanted to share with others that there are many worldwide standards that are used for waveguide apertures for shapes such as rectangular, double ridge, and circular.

The Wikipedia reference gives basic background information on the various standards:

https://en.wikipedia.org/wiki/Waveguide_flange

This Wikipedia link shows the mechanical dimensions for each :

https://en.wikipedia.org/wiki/Waveguide_(radio_frequency)

This link also showcases the geometric similarities and the differences between them :

https://www.everythingrf.com/tech-resources/waveguides-sizes

The US Military standard of MIL-F- 3922 for circular waveguides is here :

https://www.omlinc.com/images/pdf/Library/References/WG_Flange_Interface_DTL3922-67D.pdf

Note : Flange sizes are NOT Waveguide sizes - Flanges are the mechanical part that screws (machined thread) or bolts (screw and nut) together. The Waveguide is the tuned opening that allows for the radio wave to propagate down with low loss and/or reflections.