Interference canceling device

摘要

A signal which has been branched from a signal on a main line 12 is filtered by a BPF 20B and is recombined with the signal on the main line 12. The BPF 20B is a narrow band BPF, and has phase characteristics which are substantially flat in a pass band. Since phase rotation caused by frequency separation from the pass band center frequency does not occur, interference existing not only in a pin-point frequency, but over a band of frequencies can be cancelled.