Bandpass filter

A band-pass filter, wherein

• n represents a natural number equal to or more than one, and
• the band-pass filter comprises:
• an input terminal to receive an input of an RF signal;
• a multi-phase splitter to split the RF signal input to the input terminal into n RF signals whose phases each differ by 360 degrees/n;
• n signal paths to receive from the multi-phase splitter, sample, and hold one of the n RF signals whose phases each differ by the 360 degrees/n, and output the held signal, the n signal paths being connected to the multi-phase splitter, and each signal path including a sample hold element including two switches;
• a multi-phase synthesizer to synthesize n signals output from the n signal paths, the multi-phase synthesizer being connected to the n signal paths;
• an output terminal to output the signals to be synthesized by the multi-phase synthesizer;
• and
• a clock signal source to output a clock signal for driving all of switches in such a manner that phases of the clock signal match in all of the n signal paths.