1. An apparatus, comprising: a common filter to receive a first input signal into a first portion thereof and to output a first output signal from a second portion thereof, the common filter having a plurality of shared filter stages, wherein each shared filter stage can be allocated to either one of the first and second portions; a first switch to extract a second output signal from the first portion of the common filter; second switch to input a second input signal into the second portion of the common filter; and a combiner connected to the first switch and the common filter to combine the first output signal and the second output signal into a combined output signal.