AN AMPLIFIER CIRCUIT, GYRATOR CIRCUIT, FILTER DEVICE AND METHOD FOR AMPLIFYING A SIGNAL

摘要

An amplifier circuit comprising a transconductor device connected to a phase shifter section. The phase shifter section has an adjustable phase shift and an impedance at least partially dependent of the frequency of an input signal. In use, the adjustable phase shift is adjusted to have substantially the opposite value of a phase shift of the transconductor device. In an embodiment, the phase shifter section comprises a capacitor device and an adjustable resistor device which comprises an amplifier device with an input contact for receiving a resistance control signal; a first output contact connected to the capacitor devices and a second output contact connected to the transconductor device. The amplifier circuit further comprises a control device for providing said resistance control signal to the input contact of the amplifier device.