Accurately measured two-port low frequency noise and correlation of GaAs based HBTs

Accurately measured low frequency noise and correlation of GaAs based Heterojunction Bipolar Transistors (HBTs) have been reported between 10 Hz and 100 kHz. The system noises were removed from the data linearly, using noise correlation matrices. Noise shapes and correlation coefficients of HBTs from separate test pieces and of two emitters sizes were compared to reveal possible aging effects. Simulated 1/f noise with a simple non-linear transistor model was used to verify the accuracy of the method.