Patent ID: 7840196
Filing Date: 2010-11-23
Classification: H03J,H04B

Abstract:
1. A filter circuit comprising: input terminals to which an input signal is input; output terminals which output one of first and second output signals; first, second and third resonators connected in parallel between the input and output terminals, to which the input signal is supplied and which are resonated at first, second and third resonance frequencies f first, second and third switching units which switch the first, second and third resonators between an operative state and an inoperative state, respectively; and a control unit configured to control the first, second and third switching units to switch the first, second and third switching units in the operative state, so that the first, second and third resonance signals are synthesized to generate the first output signal having a relatively flat band, and control the first, second and third switching units to switch the first and third switching units in the operative state and switch the second switching unit in the inoperative state, so that no second resonance signal is generated and the first and third resonance signals are synthesized to generate the second output signal having a notch between the first and second resonance frequencies f