Patent attributes
A radio receiver system and a radio transmitter system are disclosed. The radio receiver system comprises a plurality of intermediate frequency (IF) shifting channels configured to shift incoming signals having a first frequency to an intermediate frequency in a first mixing stage, and to a second frequency in a second mixing stage. The radio transmitter system comprises a plurality of IF shifting channels configured to shift outgoing signals having a first frequency to an intermediate frequency in a first mixing stage, and to a second frequency in a second mixing stage. Since each intermediate frequency is different, the signals shifted to the second frequency combine by coherent addition, and any spurious signals combine by incoherent addition.