The large world of FET small-signal equivalent circuits (invited paper)

Abstract

The small-signal equivalent circuit modeling of microwave field-effect transistors (FETs) is an evergreen and ever flourishing research field that has to be up-to-date with technological developments. Hence, modeling techniques must be continuously adapted and extended to suit best evolving technologies. The extraction of a FET high-frequency small-signal equivalent circuit is a very active and broad research area of significant interest, owing to its use as a prerequisite for noise and large-signal modeling. The aim of this invited article is to provide in-depth knowledge, critical understanding, and new insights into how to extract a FET small-signal equivalent circuit from both theoretical and practical perspectives. To illustrate potential solutions to the key challenges faced by researchers, experimental results for different semiconductor technologies are reported and discussed. The study is focused on the hot research topic of the cold approach that has been, and still is, the most widely used technique for extracting FET small-signal models and on the active role of the transconductance for successful modeling. V C 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:749-762, 2016.

Microwave frequency small-signal equivalent circuit parameter extraction for AlInN/GaN MOSHEMT

“…The intrinsic parameters can be calculated from the intrinsic admittance parameters after de‐embedding the extrinsic parameters contribution at different bias condition. It could be mention that the intrinsic parameters could be extracted from bias dependent S‐parameters calculated over multiple voltages to design a large‐signal model . Table summarizes the extracted intrinsic parameter values for different bias conditions.…”

“…As the SSEC model connects the physical device structure to its circuit analysis, it enables study of the microwave and RF performance with device geometrical parameters. In this case, different procedures have been proposed to extract the SSEC parameters of microwave heterostructure devices from S‐parameters. During working with S‐parameters at higher frequencies require accurate transistor models up to micro/millimeter‐wave frequencies.…”

“…These effects are related to the time constants showing the inertia of the intrinsic device in responding to abrupt signal changes. Various circuit topologies have been developed to show the intrinsic nonquasi static effects . These developments show the differences among the different materials, device technologies, structures, and frequency ranges.…”

“…[11][12][13][14] As the SSEC model connects the physical device structure to its circuit analysis, it enables study of the microwave and RF performance with device geometrical parameters. In this case, different procedures have been proposed [11][12][13][14][15][16][17][18][19][20][21][22][23][24] to extract the SSEC parameters of microwave heterostructure devices from S-parameters.…”

“…Various circuit topologies have been developed to show the intrinsic nonquasi static effects. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] These developments show the differences among the different materials, device technologies, structures, and frequency ranges. The convenient and suitable intrinsic circuit part for each specified case can be determined by interpreting the intrinsic Y-(admittance) parameters.…”