I am trying to figure out Ku-band antenna
consisting a prime focus parabolic reflector
sub-reflector-->circular outer corrugated
waveguide omt. It is backfire feed so that
feed assembly ( OMT) is located behind of
reflector. I am having a hard time to understand
what is function of outer corrugation of
waveguide. The corrugation looks like rings.
Does anyone has any clue of the function of
outer corrugation of waveguide ?