Diffusion capacitance of p--n junctions and transistors

The error associated with the quasi-steady-state (q.s.s.) calculation of the diffusion capacitance of an ideal semiconductor diode, already pointed out in the literature, is interpreted in terms of a transmission-line representation of the device. The analysis is extended for short-base diodes and transistors. It is pointed out that, for diodes and transistors, the q.s.s. approach introduces a systematic error by neglecting the distributed nature of these devices.