Filter circuit and filter integrated circuit

摘要

A filter circuit and a filter integrated circuit capable of being used in a high frequency band comprises a first resistor R1 connected between an input signal source and an emitter of a common-base transistor TR1, a first capacitor C1 connected between said input signal source and a reference voltage point, a second capacitor C2 connected between said input signal source and a collector of the common-base transistor TR1, and a second resistor R2 connected between the collector of the common-base transistor and the reference voltage point. Thus, a low-pass filter which operates in a high frequency band and suppresses the influence of characteristic parameters over the filter characteristic can be constructed.