The VIAVI GC-130 GPS Antenna Coupler provides >20 dB of antenna isolation, ensuring outside GPS signals are not seen by the aircraft’s GPS receiver when simulating a user defined GPS signal. The coupler mounts directly over the aircraft’s GPS antenna. The GC-130 is designed for use with the VIAVI GPSG-1000 GPS Simulator when the supplied antenna coupler is too small to accommodate the GPS antenna of the system under test.