The effect of a variation in tone spacing on the intermodulation performance of Class A and Class AB HBT power amplifiers

The first investigation into the effect of frequency separation on the intermodulation distortion performance of Heterojunction Bipolar Transistor (HBT) power amplifiers is reported. The measured results show that the frequency spacing between the two input tones affects the intermodulation distortion performance of Class AB power amplifiers, but not Class A power amplifiers.