Patent ID: 8121715

Claim:
A radio signal transmitter for an audio source generator comprising: a reception antenna for receiving a plurality of broadcasting signals; a decision unit coupled to the reception antenna for determining intensities of the plurality of broadcasting signals received by the reception antenna; a selection unit for determining an operating frequency according to a decision result of the decision unit, comprising: a display unit coupled to the decision unit for displaying frequencies corresponding to broadcasting signals having intensities smaller than a predetermined value among the plurality of broadcasting signals according to the decision result of the decision unit; and an input interface coupled to the decision unit and the modulation unit for receiving signals outputted from a user in order to determine the operating frequency; a modulation unit coupled to the selection unit and the audio source generator for transforming an audio signal provided by the audio source generator into a broadcasting signal according to the operating frequency determined by the selection unit; and a transmission antenna coupled to the modulation unit for emitting the broadcasting signal outputted from the modulation unit in the air; wherein the predetermined value changes according to the intensities of the plurality of broadcasting signals.