A new experimental method to characterize cyclostationary noise models of bipolar devices

This paper presents an experimental method that can be used to determine the cyclostationary properties of the low-frequency noise of bipolar transistors and diodes. The noise is measured while the device works in nonlinear regime, pumped by a low-noise signal source. To measure the noise around carrier (as close as 1 Hz offset from the carrier), bridge circuits are used to balance the pump out. By applying the proposed method to evaluate the low-frequency noise of a SiGe transistor in open collector configuration, it is shown that the 1/f like noise of the device is entirely attributed to fluctuations of its conductance.