The disclosed system, device and method for a signal modulation apparatus generally includes a first signal generator suitably configured to generate a first continuous wave radio frequency (RF) signal, and a second signal generator suitably configured to generate a second continuous wave RF signal. A dual-circular polarized antenna may be adapted to receive the first continuous wave RF signal into a right-hand port and the second continuous wave RF signal into a left-hand port, where the signals are combined into a modulated RF signal in the dual-circular polarized antenna.