A novel method of extraction of emitter, Re, and base, Rb, resistances of bipolar junction transistors, BJTs, is proposed. Re and Rb are obtained from static characteristics and noise power spectral density of low frequency, 1/f, fluctuations, measured in the base and collector currents of the devices. Measurements carried out on quasi self-aligned silicon BJTs show that Re and Rb values obtained by the proposed method scale correctly with transistor dimensions and match the values estimated from the device layout.

A convenient method for determining emitter and base resistances from small signal measurements has been developed. This method is based on Neugroschel's method, but the frequency has been varied instead of varying β0. It is demonstrated that the base resistance was successfully extracted. The extracted emitter resistance depended on the collector current because of the difference between the exact gm value and the approximated one, IC/VT. It has also been shown that the proposed method is more robust than the conventional impedance-circle method even when cross-talk occurs.