Voltage controlled diode attenuator

摘要

A voltage controlled diode attenuator has no coils and, therefore, may be built in integrated circuit form. At least one pair of similarly poled diodes and a resistor are connected in a series circuit. An input signal and variable control voltage are applied to a junction between first and adjoining sides of the pair of diodes. An output voltage appears at an opposite side of one of the diodes. A differential amplifier applies a fixed bias voltage to the output terminal, and a negative feedback is connected between the opposite side of the one diode and an input to the differential amplifier.