Patent ID: 8244202

Claim:
A receiver for receiving through at least one antenna a multiband radio frequency (RF) signal having first and second RF bands which are distinct, wherein the first RF band contains high and low frequency portions which are adjacent to each other on a frequency axis, and the second RF band contains high and low frequency portions which are adjacent to each other on a frequency axis, and the first RF band contains a first existing service RF range in a selected one of the high and low frequency portions of the first RF band, and the second RF band contains a second existing service RF range in a selected one of the high and low frequency portions of the second RF band, the receiver comprising: a mixer for converting the RF signal into an intermediate frequency (IF) signal, using a single local oscillator frequency “f” produced from a single local oscillator, the single local oscillator frequency “f” being in common to the first and second RF bands; an IF bandpass filter for canceling out frequencies of the IF signal outside of a predetermined passband of the IF bandpass filter; and an analog-to-digital (A/D) converter for converting the IF signal which has passed through the IF bandpass filter, into a Low-IF signal produced by simultaneous sampling of the IF signal at a single sampling frequency, wherein the IF signal contains a first IF band corresponding to the first RF band, and a second IF band corresponding to the second RF band, the first IF band contains a first existing service IF range corresponding to the first existing service RF range, the second IF band contains a second existing service IF range corresponding to the second existing service RF range, and the local oscillator frequency “f” is determined based on a center frequency and a bandwidth of the first RF band and a center frequency and a bandwidth of the second RF band, to allow the first and second existing service IF ranges to lie outside of the predetermined passband of the IF bandpass filter, and to allow a first unused frequency portion of the first IF band which is exclusive of the first existing service IF range and a second unused frequency portion of the second IF band which is exclusive of the second existing service IF range to lie within the predetermined passband of the IF bandpass filter, to thereby allow the IF passband filter to remove the first and second existing service IF bands from the first and second IF bands, respectively, to extract the first and second unused frequency portions from the first and second IF bands, respectively.