INTERFERENCE DETECTION AND REJECTION IN A COMMUNICATION/NAVIGATION NARROWBAND AND WIDEBAND RADIO

A system comprises a radio receiver including an antenna, tunable RF notch filters that receive a desired RF signal and reject an interference signal, a LNA, a splitter, and a processor. A received RF signal is divided by the splitter and directed along a main signal path and an interference detection path. The interference detection path comprises a mixer that converts the received RF signal to an IF band, a synthesizer, and a SAW filter in communication with the mixer. The SAW filter rejects any IF signal generated due to a desired received RF signal and improves an accuracy/resolution of a detected interference frequency. The processor estimates the interference frequency based on a detected amplitude of signal samples and a synthesizer tuned frequency for that amplitude. If the detected amplitude is more than a threshold, then a control signal is sent to configure the notch filters at the interference frequency.