RF is the abbreviation for Radio Frequency. It is used to identify the actual frequency of transmitting devices. Radio stations, TV stations, two-way radios, cell phones, Bluetooth, and scores of other electronic devices emit a radio frequency. Bug sweepers will identify the presence of RF in a target area to determine if the signal is authorized and known. If not, a professional sweeping service company can use a spectrum analyzer to identify the frequency and demodulate the signal.