Patent ID: 8041320

Claim:
A radio receiver for receiving first signals of a first frequency spectrum having principal energy in a first frequency band and second signals of a second frequency spectrum having principal energy in second and third frequency bands located on either side of the first frequency band, the receiver comprising: an input for receiving an incoming signal; frequency shifting means for frequency shifting the incoming signal to form an intermediate frequency signal; and a filter for filtering the intermediate frequency signal, the filter having a frequency response that has a first passband and a second passband separated by a central stopband; and a control unit for controlling the frequency shifting means, the control unit having: a first mode for reception of the first signals, in which it controls the frequency shifting means so as to frequency shift the incoming signal so that (a) the first frequency band of the incoming signal is shifted onto one of the first and second passbands and (b) one of the second and third frequency bands of the incoming signal is shifted onto the central stopband; and a second mode for reception of the second signals, in which it controls the frequency shifting means so as to frequency shift the incoming signal so that (a) the second and third frequency bands of the incoming signal are shifted onto the first and second passbands respectively and (b) the first frequency band of the incoming signal is shifted onto the central stopband.