Predicting 1/f AM and PM noise in Si BJT amplifiers: a new computer program

We show that a high-resolution software package can be adapted to calculate the amplitude modulation (AM) and phase modulation (PM) noise performance of Si Bipolar Junction Transistor (BJT) amplifiers. Our simulations predict that the PM noise induced by bias current noise can be greatly suppressed by operating at special bias conditions. Furthermore, a dc balance amplifier circuit is introduced to stabilize the base-to-collector voltage. The total sensitivity of PM noise to power supply noise using dc balance architecture can be reduced by 40 dB compared to basic amplifier architecture. This is experimentally verified.