## 5 Conclusions  
We presented a three-stage GaN HEMT LNA MMIC based on the 0.15-\(\upmu\)m GaN-on-SiC technology, for use in 5G NR FR2 base station applications, for the frequency range of 26-30 GHz. In this design, it was demonstrated that adopting a series inductor between the stages enhances the stability performance with minimum degradation of the small-signal gain and NF performance, specifically at the operating frequency. Through performance  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Reference** & **This Work** & [17] & [24] & [18] & [21] & [23] \\ \hline Frequency & & & & & & \\ (GHz) & 26–30 & 26–31 & 26–40 & 27–31 & 34–37.5 & 33–38 \\ \hline Gain & & & & & & \\ (dB) & 20.2 & 18.9–24.5 & \(>\)23 & 14.4–19.6 & 31 & 25–26 \\ \hline \(S11/S22\) & & & & & & \\ (dB) & \(<\)-10/\(<\)-10 & -12.5/\(<\)-6.5 & \(<\)-5/\(<\)-10 & \(<\)-5/\(<\)-10 & \(\geq\)10 \\ \hline NF & & & & & & \\ (dB) & 2.42–2.56 & 4–5 & 1.7–2.7 & 3.7–3.9 & 2.4–2.6 & 2.0–2.2 \\ \hline OP1 dB & & & & & & \\ (dBm) & 17.2 & 12.5 & 12–22 & NA & 23 & 20 \\ \hline OIP3 & & & & & & \\ (dBm) & 32.2 & NA & 20–32 & NA & 32 & 28.4 \\ \hline Stability \({}^{1}\) & \begin{tabular}{c} Uncon. \\ Stable \\ (up to 7.7) \\ \end{tabular} & NA & \begin{tabular}{c} Uncon. \\ Stable \\ (Up to \(\sim\)9) \\ \end{tabular} & \
\begin{tabular}{c} Uncon. \\ Stable \\ (NA) \\ \end{tabular} &
\begin{tabular}{c} Uncon. \\ Stable \\ (NA) \\ \end{tabular} & NA \\ \hline Power & & & & & & \\ (W) & 0.32 & NA & 0.43 & 0.56 & 1.3 & NA \\ \hline Chip Size \({}^{2}\) & 2.66 & 6 & NA & 4.08 & 7.2 & 5.5 \\ \hline \multirow{2}{*}{Process} & 0.15-\(\upmu\)m & 0.15-\(\upmu\)m & 0.1-\(\upmu\)m & 0.15-\(\upmu\)m & 0.1-\(\upmu\)m & 0.1-\(\upmu\)m \\  & GaN-on-SiC & GaN-on-SiC & GaN-on-Si & GaN-on-SiC & GaN-on-Si & GaN-on-Si \\ \hline \hline \end{tabular} \({}^{1}\). NA: Not Available. \({}^{2}\). Including bonding pads.  
\end{table}
Table 3: Performance summary and comparison with previously reported work.  
Figure 14: Measured IB OIP3 performance with \(f_{1}=f_{RF}+20\) MHz and \(f_{2}=f_{RF}+40\) MHz.  
verification of the implemented design, it was ensured that the series-inductor-based technique could be successfully utilized in the GaN HEMT design to improve the gain and stability performance.  
Conceptualization, H.A., H.J., D.K., S.L., and J.H.; methodology, H.A., H.J., D.K., S.L., and J.H.; validation, H.A., H.J., S.-M.S., and J.H.; data curation, H.A., H.J. and S.-M.S.; writing--original draft preparation, H.A. and J.H.; writing--review and editing, H.J., D.K., S.L.; funding acquisition, J.H. All authors have read and agreed to the published version of the manuscript.  
This research was supported in part by the Institute for Information and communications Technology Planning (IITP) grant funded by the Ministry of Science and ICT (2020-0-00158-001) and in part by the Regional Innovation Strategy (RIS) through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (MOE) (2021 RIS-004).  
Not applicable.  
The authors would like to thank [PERSON] of ICT Creative Research Lab, Electronics and Telecommunication Research Institute (ETRI) for their assistance with measurement equipment.  
The authors declare no conflict of interest.