A COMPACT MODEL FOR THE CUTOFF FREQUENCY IN HIGH-SPEED BIPOLAR-TRANSISTORS

A compact physical model for high speed bipolar junction transistors ( BST) in integrated rf-circuits is presented. The model, which suits bo th homo- and heterojunction devices, is based on the de Graaf-Klooster man formalism for the modelling of BJTs, but adds important heterostru cture device physics and incorporates also the physical properties of the SiGe material The model implemented in APLAC circuit simulator, sh ows good agreement between the simulation results and measured data bo th for pure silicon BJTs and for SiGe-base heterojunction transistors.