WIDE BAND AMPLIFIER CIRCUIT AND SIGNAL DISCRIMINATING CIRCUIT USING IT

摘要

A wide band amplifier circuit (10) which uses an active element (11) provided with a base-corresponding terminal, an emitter-corresponding terminal and a collector-corresponding terminal, which has an input circuit where an input signal voltage to ground is higher at the emitter-corresponding terminal than at the base-corresponding terminal, and which ensures a stable amplification up to a region higher in frequency than a conventional amplifier; wherein an impedance is kept high between the collector-corresponding terminal and the base-corresponding terminal with respect to a signal frequency and a loading output circuit (12) is connected between the collector-corresponding terminal and the emitter-corresponding terminal; whereby providing a wide band amplifier circuit (10) capable of amplifying signals over a wide frequency band to thereby provide a signal discriminating circuit capable of conventionally-difficult duplex communication by using the circuit (10).