A harmonic translational filter includes a first path, a second path and a signal combiner. The first path has a first translational filter that is driven by a plurality of first oscillation signals, and is arranged to generate a first output signal according to an input signal. The second path has a second translation filter that is driven by a plurality of second oscillation signals that are different from the first oscillation signals in phase. The second path is coupled to the first path and arranged to generate a second output signal according to the input signal. The signal combiner is coupled to the first path and the second path, and arranged to combine the first output signal and the second output signal to generate a filtered signal.

A frequency converting circuit including: an impedance network having a first pair of terminals and operable to provide a first signal in a frequency band centered at a first frequency f1; an output network having second and third pairs of terminals and configured to pass, between the second and third pairs of terminals, a second signal in a frequency band centered at a second frequency f2 different from f1; a pump circuit having a fourth pair of terminals and operative to provide, at the fourth pair of terminals, a third signal at a pump frequency fp, where fp?f1 and f2; and a frequency converter having a first port connected to the first terminals, a second port connected to the second terminals and a third port connected to the fourth terminals, the frequency converter being operative to cause the difference between f1 and f2 to be equal to fp.

A frequency converting circuit including: an impedance network having a first pair of terminals and operable to provide a first signal in a frequency band centered at a first frequency f1; an output network having second and third pairs of terminals and configured to pass, between the second and third pairs of terminals, a second signal in a frequency band centered at a second frequency f2 different from f1; a pump circuit having a fourth pair of terminals and operative to provide, at the fourth pair of terminals, a third signal at a pump frequency fp, where fp?f1 and f2; and a frequency converter having a first port connected to the first terminals, a second port connected to the second terminals and a third port connected to the fourth terminals, the frequency converter being operative to cause the difference between f1 and f2 to be equal to fp.