Circuit modeling of low-noise microwave transistors: its role in supporting a complete device characterization

This paper discusses the role of microwave low-noise transistor modeling at a circuit level to reduce characterization requirements, as from the author´s experience in the field. It is well known that a complete procedure involving measurements of small-signal and noise parameters vs. frequency, bias and temperature conditions is a hard task. The appropriate use of a linear circuit model equipped with noise sources offers a viable alternative to complex and time-consuming experimental tests aimed at extracting a large amount of information on the device performance. This work reports the results regarding the complete characterization of high electron mobility transistors (HEMT) which offer outperforming values of noise figure and gain at microwave and millimeter-wave frequencies.