An HBT noise model valid up transit frequency

A comprehensive HBT noise model for circuit simulation is presented that de scribes the microwave noise behavior up to the transit frequency. It is bas ed on diode noise theory, and requires only the small-signal equivalent cir cuit, including the thermal resistance, and the de bias point. A main featu re is correlation of the shot-noise sources at the pn Junctions. The model is verified by measurements of the four noise parameters of an InGaP/GaAs H BT, varying frequency and bias conditions.