On the cyclostationary properties of the 1/f noise of microwave semiconductor devices

Abstract

This paper addresses, from an experimental perspective, the long-standing question on whether the 1/f noise of microwave semiconductor devices should be considered cyclostationary in compact models. By using a simple instrumentation setup and basic mixer concepts, it will be shown that the external equivalent current noise sources of such devices simply CANNOT be stationary. To demonstrate our ideas, a through experimental analysis was carried out on purely-resistive bridge circuits made up of microwave varactors and transistors under large-signal operation whose DC current component is kept constant.When computing the voltage noise power of specific circuit arrangements, errors in excess of 20dB may be induced if the stationary concept is adopted. The difference between the stationary or cyclostationary concepts will be simulated with the aid of the simulator ADS from Agilent.

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

“…In a recent paper, a clear experimental evidence of the cyclostationary properties of the 1/f-like noise of semiconductor devices was given, showing that the equivalent current noise sources simply cannot be stationary [3]. Such evidence supports previous experimental initiatives in the domain [4], [5], [6].…”

“…The expression of the PSD of the equivalent current noise source is determined from observing the voltage fluctuations measured across the device terminals when it goes from a DC bias regime into a forced nonlinear regime [3].…”

“…The setup shown in figure 4 was recently used to demonstrate a clear experimental evidence of the cyclostationary properties of the equivalent current noise sources of microwave varactors, transistors in open collector configuration and in forward active (normal) configuration [3].…”

“…In the case of a periodically driven device, the PSD is thus periodically time variant. By properly choosing the measurement conditions, the difference between the experimental data and simulation results from a stationary model may be as much as 20dB [3], and enables the determination of the cyclostationary properties of the noise source under investigation.…”

Experimental characterization of the cyclostationary low-frequency noise of microwave semiconductor devices under large signal operation

“…They also employed bridge circuits and a differential amplifier, and pump frequencies of 650 Hz, 6.95 kHz, and 20 kHz. More recently, Lisboa de Souza et al [13] also used the ideas from [4] to give an experimental evidence of the cyclostationary properties of 1/f noise sources of microwave varactors and transistors at the external ports. Details of that experimental setup will be given in Section V.…”