How to Measure the Frequency Response of Nanoscale Transistors

One of the first questions asked about a novel transistor is how fast does it operate, or, more precisely, what is its frequency response? This often elicits a measurement of its “cutoff frequency.” However, it may not be possible to measure cutoff frequency of very small transistors which have small currents. This article describes an alternative and much simpler measurement, dubbed” direct power gain,” explains the measurement method and practical details, and compares the meaning of frequency response as measured by the two methods.