Radio frequency amplifier with improved intermodulation performance

摘要

A radio frequency amplifier of improved intermodulation performance is provided by connecting first and second transconductance amplifiers in antiphase so that third order intermodulation products cancel each other but the reduction in gain is relatively small. The transconductance stages comprise long tail pairs of transistors provided with tail current sources formed by transistors whose bases are connected to a bias voltage source. The first transistor has an emitter connected via a resistor to ground. The second transistor has an emitter connected via another resistor to the emitter of the first transistor.