Complex band pass filter and receiver
AssigneeKabushiki Kaisha Toshiba
InventorYosuke Ogasawara
Life of this patent
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Abstract
According to one embodiment, a complex band pass filter comprises a first active filter circuit 10 to receive a first input signal on its input end and a second active filter circuit 20 to receive a second input signal on its input end, the second input signal having a 90-degree phase difference from the first input signal. A predetermined offset is imparted to the first input signal and the second input signal through the first and second signal level adjusting units (30, 40). A differential signal between the output signals of the first and second active filter circuits (10, 20) is outputted.
Claims20
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.
A complex band pass filter of an order higher than one which includes multiple stages of active filter circuits, the 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.
A receiver including a complex band pass filter which comprises:
- 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.
Dependencies are inferred from the claim text.