Patent ID: 7848710

Claim:
A radio circuit comprises: a mixing module coupled to mix a first signal having a first carrier frequency with a second signal having a second carrier frequency to produce a mixed signal having a frequency sum component and a frequency difference component; a first adjustable resonant circuit tuned to provide a notch filter response corresponding to the frequency sum component; a second adjustable resonant circuit tuned to provide a bandpass filter response corresponding to the frequency difference component, wherein the first and second adjustable resonant circuits alter the mixed signal to produce a converted signal; a second mixing module coupled to mix the converted signal with a third signal having a third carrier frequency to produce a second mixed signal having a second frequency sum component and a second frequency difference component; a third adjustable resonant circuit tuned to provide a notch filter response corresponding to the second frequency sum component; and a fourth adjustable resonant circuit tuned to provide a band pass filter response corresponding to the second frequency difference component.