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".