Patent ID: 7860478

Claim:
A poly-phase filter comprising: a calibration control block generating a first filter characteristic control signal and a second filter characteristic control signal for determining electrical characteristics of the filter in response to first and second control signals; and a poly-phase filter block performing filtering on a plurality of input signals having different phases from each other in response to the first and second filter characteristic control signals, wherein the poly-phase filter block comprises at least one poly-phase filter circuit which performs filtering on a plurality of input signals having different phases from each other in response to the first and second filter characteristic control signals, wherein the poly-phase filter circuit comprises a number of phase filters corresponding to a plurality of the input signals, wherein a plurality of the input signals are first to fourth input signals having phases which are different from each other by 90°, and wherein a number of the phase filters comprise: a first phase filter performing filtering on the first input signal based on the second input signal; a second phase filter performing filtering on the second input signal based on the third input signal; a third phase filter performing filtering on the third input signal based on the fourth input signal; and a fourth phase filter performing filtering on the fourth input signal based on the first input signal, and wherein filter characteristics of the four phase filters are controlled by the first and second filter characteristic control signals.