Patent ID: 9148124
Filing Date: 2015-09-29
Classification: H03H,H04B

Abstract:
1. A complex band pass filter comprising: a first active filter circuit for a first input signal to be supplied to; a second active filter circuit for a second input signal to be supplied to, the second input signal having a 90-degree phase difference from the first input signal; first signal level adjusting unit that adjusts the level of the first input signal; second signal level adjusting unit that adjusts the level of the second input signal; a first feedback circuit that feeds back an output signal of the first active filter circuit to the input side of the second active filter circuit; a second feedback circuit that feeds back an output signal of the second active filter circuit to the input side of the first active filter circuit; and output unit that obtains an output from a differential signal between the output signal of the first active filter circuit and the output signal of the second active filter circuit, wherein a predetermined offset is imparted to the level of the first input signal and the level of the second input signal through the first signal level adjusting unit and the second signal level adjusting unit.