Uncertainty Propagation in GaN HEMT Small-Signal Models for Millimeter-Wave Circuit Design Applications
Year: 2026
Type: article
Abstract: This paper investigates the impact of S-parameter measurement uncertainties on broadband modeling and circuit design using gallium nitride (GaN) high electron mobility transistors (HEMTs) from 0.5–110 GHz. A process for creating a small-signal model (SSM) for the GaN device is described, as well as a method for propagating uncertainties through SSM simulations. This work identifies two salient SSM parameters to which uncertainties can be applied to replicate the trends in the measurement uncertainties. A comparison of the propagated uncertainties in the measurement and the model data is analyzed. Two matching network circuits were designed utilizing the SSM, and the effect of uncertainties on these circuit designs is discussed. These results indicate that measurement uncertainty has a notable impact on$S_{11}$and$S_{22}$in both conjugate match network designs and specified gain network designs, with more variation present in conjugate match designs. From these results, we conclude that there is an inverse relationship between the amount of mismatch in RF matching network circuit designs and the impact of uncertainties on their input and output matching conditions. Even in circuits designed for no mismatch, there is still a noticeable variation in S-parameters, particularly in the phase of$S_{22}$. The findings of this investigation could be useful for RF engineers to better understand uncertainties in measurements and extracted models, as well as integrated circuit designs that utilize them.
Source: IEEE Journal of Microwaves
Authors: Jason Shell, Edward Gebara, Nicholas C. Miller
Institution: Michigan State University
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,075
Award: G187758728
OpenAlex ID: W7133224824