polarisation issue
polarisation issue
(OP)
A horn antenna with its aperture, and launch probe vertical, will produce vertical polarisation (with a small ammount of H pol). However, if the antenna was placed on its back so as to be looking vertically up the launch probe is now horizontal as is its cross pol component. What polarisation would be produced for the main lobe and side lobes?
RE: polarisation issue
RE: polarisation issue
RE: polarisation issue
Bottom line, for testing polorization either V or Horz placed won't make much difference because the polorarity of the horn must match the pol of the source satellite or Boresite feed. It must be manually adjusted (unless you have a pol motor.)
Main lobe and side lobe depends on the source as well, typically for earth stations the side lobe should be about 14dB down from the main lobe, with each side being a mirror image of the other.
Also, Signals are not true Horz or Vert. Although they are not specified as eliptical, every linear signal has a small eliptical shape, which is where the slight horizontal component fits in.
Iden