Dynamic high frequency phenomena in the base-emitter junction of bipolar transistors

An improved nonlinear high-frequency circuit model for the bipolar transistor is presented, based on considerations on the dynamic phenomena occurring in the normally forward biased base-emitter junction. The model incorporates higher-order circuit elements to obtain increased accuracy in circuit simulation at high frequencies. The model is derived from device physics by solving the diffusion equation in the base region by a quasistatic expansion