DIFFERENTIAL AMPLIFIER CIRCUIT FOR RF SIGNALS FOR IMPROVEMENT LINEARITY OF SMALL SIGNALS

摘要

PURPOSE: A differential amplifier circuit for RF signals for improvement of linearity of small signals is provided to improves linearity of the third-order intermodulation signal by using characteristic of an FET. CONSTITUTION: A differential amplifier circuit for RF signals for improvement of linearity of small signals includes a differential amplifier(10) for differential-amplifying an input signal at a normal operation point with an external DC gate voltage, a differential amplifier(20) for generating the third-order intermodulation signal, which non-linearly differential-amplifies the input signal with an external DC gate voltage to generate the third-order intermodulation signal, and an insulator(30) for differently applying the DC gate voltages supplied to the two differential amplifiers for insulation from a DC power supply.