INTERFERENCE WAVE LEVEL DETECTION CIRCUIT, NARROW BAND INTERFERENCE WAVE LIMITING DEVICE USING THE SAME AND COMMUNICATION EQUIPMENT USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an interference wave level detection circuit detecting the level of a narrow band interference wave by connecting power detectors to an input side and an output side and obtaining the level of the narrow band infrequence wave containing in an inputted signal. SOLUTION: A signal inputted from an input terminal 2 is amplified by an amplification rate variable amplifier 4 and is divided into two by a signal distributor 21. One is inputted an static wave filter 22 and the other is inputted to a power detector 24. The signal outputted from the static magnetic wave filter 22 is divided into two by a signal distributor 23 and one signal is outputted from an output terminal 7 and other is inputted to a power detector 25. The outputs of the power detectors 24 and 25 are inputted to a power difference detector 26. The power difference detector 26 detects the difference of power detected by the two power detectors 24 and 25, namely, power limited by the static magnetic wave filter 22 among the power of a narrow band interference wave. Thus, the level of the narrow band interference wave can be detected in an interference wave level defector 29.