Patent ID: 7385465

Claim:
A switchable dual-band filter for passing a first passband corresponding to a first frequency, and a second passband corresponding to a second frequency, said switchable dual-band filter comprising: first and second switchable resonators; a coupling structure having two ends respectively connecting said first and said second switchable resonators, and coupling said first resonator to said second resonator; an input impedance conversion circuit connecting an input terminal and said first resonator, and converting the impedance on said input terminal into two distinct impedances that correspond to said first and said second operating frequencies; and an output impedance conversion circuit connecting an output terminal and said second resonator, and converting the impedance on said output terminal into two distinct impedances that correspond to said first and said second operating frequencies; wherein each said impedance conversion circuit converts 50Ω terminal impedance into two resistive impedances at said first and said second operating frequencies.