Antennas

VHF 118-137 Mhz UHF 1030-1090 MHz  and GPS antennas specific for aeronautical use

Aeronautical Radio Antennas are based on the   QUARTER WAVE Graund Plane principle.

Aeronautical radio frequencies range from   ( 117.945 Mhz to 136.000 Mhz )   VHF

Aeronautical transponder frequencies range from   ( 1030 Mhz to 1090 Mhz )   UHF

GPS antennas have parallel channels in simultaneous reception (usually 20-30)

The antennas are relatively simple  , see photo RAMI AV-534, the "ground floor" is fundamental i.e. find the metal plane on which the antenna is fixed which allows correct reception and transmission with a   SWR or SWR value of 1. This is also valid for UHF antennas for transponders. GPS antennas, on the other hand, only need "Free Sky".