隨著第五代行動通訊（5G）與衛星通訊系統往毫米波頻段發展，Ka 頻段對高效能接收前端的需求日益增加。低雜訊放大器位於接收機前端，其雜訊指數與增益直接決定整體系統的靈敏度，而頻寬與穩定度則決定可用頻段與工作可靠度。氮化鎵（GaN）具備高崩潰電壓、高功率密度與良好的雜訊特性，適合用於高線性度、可承受大訊號的毫米波接收前端。
本論文採用穩懋半導體 0.12-µm GaN-on-SiC HEMT 製程，完成三顆工作於 28 GHz 的 Ka 頻段 GaN 低雜訊放大器的設計。前兩顆晶片已完成下線並量測，第三顆晶片則完成設計並下線。三顆晶片依序探討低雜訊設計、回授穩定化，以及寬頻輸入／輸出匹配等設計議題。
第一顆晶片採用兩級共源架構搭配微帶線源極退化，以低雜訊為主要設計目標。此晶片已下線並完成量測：雜訊指數為 1.4–2.2 dB、增益為 17.4–20.2 dB、3-dB 增益頻寬為 24.7–28.3 GHz、直流功耗為 171.9 mW、晶片面積為 2 × 2 mm²。此量測結果驗證了所採用低雜訊設計流程於 GaN12 製程中的可行性。
第二顆晶片改採三級架構，於第一級導入負回授，並增加第三級以補償回授造成的增益下降，同時調整頻帶內的增益平坦度。此晶片已下線並完成量測：增益為 17.4–20.4 dB、3-dB 增益頻寬為 25.8–28.9 GHz、雜訊指數於 26–28 GHz 內低於 4 dB、晶片面積為 3 × 1 mm²。然而，直流功耗上升至 702.67 mW。
第三顆晶片同樣採用三級架構，並提出全電容式 π 型級間匹配網路，以降低後級負載對第一級預先最佳化之輸入與雜訊匹配條件的影響。此網路與第一級輸入匹配及後級電路在降低第三級汲極偏壓的條件下進行共同最佳化，模擬結果顯示電路仍可維持寬頻增益與輸入／輸出匹配。後佈局模擬顯示，其 3-dB 增益頻寬涵蓋 25.5–32.7 GHz，輸入與輸出反射係數於 25.9–30.6 GHz（約 4.7 GHz）範圍內同時低於 −10 dB，最小雜訊指數為 3.32 dB，直流功耗為 267 mW，晶片面積為 3 × 1 mm²。第三顆晶片已完成版圖設計並送製，其實驗量測與驗證列為未來工作。

As fifth-generation (5G) mobile and satellite communication systems move toward millimeter-wave frequencies, the migration toward the Ka band has increased the demand for high-performance receiver front-ends. The low-noise amplifier (LNA), located at the front of the receiver, determines the overall system sensitivity through its noise figure and gain, while its bandwidth and stability determine the usable band and operating reliability. Gallium nitride (GaN) offers a high breakdown voltage, high power density, and favorable noise performance, making it well suited to linear, large-signal-tolerant millimeter-wave front-ends.
This thesis presents the design and implementation of three 28 GHz Ka-band GaN LNAs in the WIN Semiconductor 0.12-µm GaN-on-SiC HEMT process, progressively addressing low noise, stability, and wideband simultaneous input/output matching.
The first chip uses a two-stage common-source topology with microstrip source degeneration and is optimized for low noise. The chip was fabricated and characterized on-wafer: the measured results are a noise figure of 1.4–2.2 dB, a gain of 17.4–20.2 dB, and a 3-dB gain bandwidth of 24.7–28.3 GHz, at a DC power dissipation of 171.9 mW and a die area of 2 × 2 mm². These measurement results validate the adopted low-noise design methodology in the GaN12 process.
The second chip adopts a three-stage topology in which negative feedback is applied to the first stage and a third stage is added to compensate for the feedback-induced gain reduction and to adjust the in-band gain flatness. The chip was fabricated and characterized on-wafer: the measured gain is 17.4–20.4 dB, the 3-dB gain bandwidth is 25.8–28.9 GHz, the noise figure is below 4 dB over 26–28 GHz, and the die area is 3 × 1 mm². The DC power dissipation, however, rises to 702.67 mW.
The third chip retains the three-stage architecture and introduces an all-capacitor π inter-stage matching network designed to reduce the sensitivity of the pre-optimized first-stage input- and noise-matching conditions to downstream loading. The inter-stage network is co-optimized with the first-stage input network and the following stages under a reduced third-stage drain bias, and simulation results show that wideband gain and overlapping input/output matching are maintained. Post-layout simulation shows a 3-dB gain bandwidth of 25.5–32.7 GHz, with both S11 and S22 below −10 dB over 25.9–30.6 GHz (about 4.7 GHz). The minimum simulated noise figure is 3.32 dB, and the DC power dissipation is 267 mW. The die area is 3 × 1 mm². The third chip has been submitted for fabrication, and experimental characterization is left as future work.

[1] NR; User Equipment (UE) radio transmission and reception; Part 2: Range 2 Standalone, 3GPP TS 38.101-2, 3rd Generation Partnership Project, 2024.
[2] F. Alimenti, P. Mezzanotte, G. Simoncini, V. Palazzi, R. Salvati, G. Cicioni, L. Roselli, F. Dogo, S. Pauletto, M. Fragiacomo, and A. Gregorio, "A Ka-Band Receiver Front-End With Noise Injection Calibration Circuit for CubeSats Inter-Satellite Links," IEEE Access, vol. 8, pp. 106785–106798, 2020, doi: 10.1109/ACCESS.2020.3000675.
[3] M. Uko, S. Ekpo, S. Enahoro, F. Elias, R. Unnikrishnan, and Y. Al-Yasir, "Highly Adaptive Reconfigurable Receiver Front-End for 5G and Satellite Applications," Technologies, vol. 13, no. 4, p. 124, 2025, doi: 10.3390/technologies13040124.
[4] H. T. Friis, "Noise Figures of Radio Receivers," Proceedings of the IRE, vol. 32, no. 7, pp. 419–422, 1944, doi: 10.1109/JRPROC.1944.232049.
[5] X. Tong, S. Zhang, P. Zheng, Y. Huang, J. Xu, X. Shi, and R. Wang, "A 22–30-GHz GaN Low-Noise Amplifier With 0.4–1.1-dB Noise Figure," IEEE Microwave and Wireless Components Letters, vol. 29, no. 2, pp. 134–136, 2019, doi: 10.1109/LMWC.2018.2886074.
[6] F. Mao, Z. Chen, B. Li, Z. Wu, X. Chen, and Q. Guan, "A 23–29 GHz GaN Low-Noise Amplifier with Drain-to-Source Coupling Feedback," Electronics, vol. 13, no. 21, p. 4154, 2024, doi: 10.3390/electronics13214154.
[7] S. Colangeli, A. Bentini, W. Ciccognani, E. Limiti, and A. Nanni, "GaN-Based Robust Low-Noise Amplifiers," IEEE Transactions on Electron Devices, vol. 60, no. 10, pp. 3238–3248, 2013, doi: 10.1109/TED.2013.2265718.
[8] S. Zhang, J. Xu, P. Zheng, R. Wang, and X. Tong, "An 18–31-GHz GaN-Based LNA With 0.8-dB Minimum NF and High Robustness," IEEE Microwave and Wireless Components Letters, vol. 30, no. 9, pp. 896–899, 2020, doi: 10.1109/LMWC.2020.3011135.
[9] L. Pace, P. E. Longhi, W. Ciccognani, S. Colangeli, F. Vitulli, F. Deborgies, and E. Limiti, "DC Power-Optimized Ka-Band GaN-on-Si Low-Noise Amplifier With 1.5 dB Noise Figure," IEEE Microwave and Wireless Components Letters, vol. 32, no. 6, pp. 555–558, 2022, doi: 10.1109/LMWC.2021.3139769.
[10] L. Pace, S. Colangeli, W. Ciccognani, P. E. Longhi, E. Limiti, R. Leblanc, M. Feudale, and F. Vitobello, "Design and Validation of 100 nm GaN-On-Si Ka-Band LNA Based on Custom Noise and Small Signal Models," Electronics, vol. 9, no. 1, p. 150, 2020, doi: 10.3390/electronics9010150.
[11] C. Huang, Z. Zhang, X. Wang, H. Liu, and G. Zhang, "An MMIC LNA for Millimeter-Wave Radar and 5G Applications with GaN-on-SiC Technology," Sensors, vol. 23, no. 14, p. 6611, 2023, doi: 10.3390/s23146611.
[12] L. Lan, Z. Zhang, C. Huang, and G. Zhang, "A GaN-on-SiC Millimeter-Wave Low Noise Amplifier Using Hybrid-Matching Technique for 5G n258 Applications," Microw. Opt. Technol. Lett., vol. 66, no. 11, p. e70031, 2024, doi: 10.1002/mop.70031.
[13] F. Mao, Z. Chen, B. Li, Z. Wu, X. Chen, and S. Yang, "A 26-GHz Low Noise Amplifier With 1.6-dB Minimum Noise Figure in 0.15-μm GaN-on-SiC Process," Microw. Opt. Technol. Lett., vol. 66, no. 11, p. e70038, 2024, doi: 10.1002/mop.70038.
[14] H. Ahn, H. Ji, D. Kang, S.-M. Son, S. Lee, and J. Han, "A 26–30 GHz GaN HEMT Low-Noise Amplifier Employing a Series Inductor-Based Stability Enhancement Technique," Electronics, vol. 11, no. 17, p. 2716, 2022, doi: 10.3390/electronics11172716.
[15] W. Chang, J. Park, K. Cho, J. Jeong, H. G. Ji, B.-G. Min, J. M. Lee, J. Kim, G. Lee, and D. Kang, "A Ka‐Band GaN low‐noise amplifier monolithic microwave integrated circuit using external source interconnect for gate‐side parasitic suppression," ETRI Journal, 2025, doi: 10.4218/etrij.2025-0282.
[16] D.-y. Yuan, C.-x. Duan, W.-l. Liu, H.-h. Jia, Y. Lu, X.-h. Ma, and Y. Hao, "25~32GHz Wideband Low Noise Amplifier using 0.15µm GaN-on-SiC Technology," in 2023 IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes for RF and THz Applications (IMWS-AMP), 2023, pp. 1–3, doi: 10.1109/IMWS-AMP57814.2023.10381075.
[17] C. Florian, P. A. Traverso, and A. Santarelli, "A Ka-Band MMIC LNA in GaN-on-Si 100-nm Technology for High Dynamic Range Radar Receivers," IEEE Microwave and Wireless Components Letters, vol. 31, no. 2, pp. 161–164, 2021, doi: 10.1109/LMWC.2020.3047152.
[18] C. Liang, S. Gan, B. Tang, Z. Gao, Q. Dong, Y. Zhao, Y. Xie, Y. Xin, B. Zhang, D. Li, and L. Geng, "A 21.3-to-30.1 GHz Reversed Current-reuse LNA with Load Regulation Enhancing Wideband Noise and Input Matching," in 2024 IEEE European Solid-State Electronics Research Conference (ESSERC), 9–12 Sept. 2024, pp. 281–284, doi: 10.1109/ESSERC62670.2024.10719523.
[19] Z. Dai, C. Li, J. Yan, T. Zhang, and H. Bao, "A Low-power, High-gain and Excellent Noise Figure GaN-on-SiC LNA Monolithic Microwave Integrated Circuit (MMIC) operating at Ka-band for 5G/6G Application," The Applied Computational Electromagnetics Society Journal (ACES), vol. 38, no. 10, pp. 822–828, 2023, doi: 10.13052/2023.ACES.J.381010.
[20] V. Sharma, P. Longhi, W. Ciccognani, S. Colangeli, A. Serino, S. Sharma, and E. Limiti, "Frequency-Bounded Matching Strategy for Wideband LNA Design Utilising a Relaxed SSNM Approach," Applied Sciences, vol. 15, no. 15, p. 8148, 2025, doi: 10.3390/app15158148.
[21] J. S. Seo, J. H. Hwang, K. J. Kim, and G. H. Ahn, "High Linearity Ka-band GaN Hemt Low Noise Amplifier," in 2021 International Conference on Information and Communication Technology Convergence (ICTC), 20–22 Oct. 2021, pp. 383–385, doi: 10.1109/ICTC52510.2021.9621019.
[22] S. Haque, C. Andrei, M. Wolf, O. Hilt, and M. Rudolph, "Switch Integrated Ka-Band Low Noise Amplifier in GaN/AlN HEMT Technology," in 2024 19th European Microwave Integrated Circuits Conference (EuMIC), 23–24 Sept. 2024, pp. 351–354, doi: 10.23919/EuMIC61603.2024.10732731.
[23] E. M. Suijker, M. Rodenburg, J. A. Hoogland, M. v. Heijningen, M. Seelmann-Eggebert, R. Quay, P. Bruckner, and F. E. v. Vliet, "Robust AlGaN/GaN Low Noise Amplifier MMICs for C-, Ku- and Ka-Band Space Applications," in 2009 Annual IEEE Compound Semiconductor Integrated Circuit Symposium, 11–14 Oct. 2009, pp. 1–4, doi: 10.1109/csics.2009.5315640.
[24] Y. H. Huang, S. C. Huang, and C. H. Wu, "A 23–33 GHz GaN HEMT LNA with High Linearity for UAV Radar Applications," in 2025 IEEE International Symposium on Radio-Frequency Integration Technology (RFIT), 25–27 Aug. 2025, pp. 175–177, doi: 10.1109/RFIT65667.2025.11364577.
[25] D. K. Shaeffer and T. H. Lee, "A 1.5-V, 1.5-GHz CMOS low noise amplifier," IEEE Journal of Solid-State Circuits, vol. 32, no. 5, pp. 745–759, 1997, doi: 10.1109/4.568846.
[26] N. Trung-Kien, K. Chung-Hwan, I. Gook-Ju, Y. Moon-Su, and L. Sang-Gug, "CMOS low-noise amplifier design optimization techniques," IEEE Transactions on Microwave Theory and Techniques, vol. 52, no. 5, pp. 1433–1442, 2004, doi: 10.1109/TMTT.2004.827014.
[27] H. Nyquist, "Thermal Agitation of Electric Charge in Conductors," Physical Review, vol. 32, no. 1, pp. 110–113, 1928, doi: 10.1103/PhysRev.32.110.
[28] A. v. d. Ziel, Noise in solid state devices and circuits. New York: Wiley, 1986.
[29] H. A. Haus, W. R. Atkinson, G. M. Branch, W. B. Davenport, W. H. Fonger, W. A. Harris, S. W. Harrison, W. W. McLeod, E. K. Stodola, and T. E. Talpey, "Representation of Noise in Linear Twoports," Proceedings of the IRE, vol. 48, no. 1, pp. 69–74, 1960, doi: 10.1109/JRPROC.1960.287381.
[30] G. Gonzalez, Microwave transistor amplifiers: analysis and design, 2nd ed. Upper Saddle River, NJ: Prentice Hall, 1997.
[31] B. Razavi, RF Microelectronics, 2nd ed. Upper Saddle River, NJ: Prentice Hall, 2011.
[32] J. Rollett, "Stability and Power-Gain Invariants of Linear Twoports," IRE Transactions on Circuit Theory, vol. 9, no. 1, pp. 29–32, 1962, doi: 10.1109/TCT.1962.1086854.
[33] M. L. Edwards and J. H. Sinsky, "A new criterion for linear 2-port stability using a single geometrically derived parameter," IEEE Transactions on Microwave Theory and Techniques, vol. 40, no. 12, pp. 2303–2311, 1992, doi: 10.1109/22.179894.
[34] H. Fukui, "Available Power Gain, Noise Figure, and Noise Measure of Two-Ports and Their Graphical Representations," IEEE Transactions on Circuit Theory, vol. 13, no. 2, pp. 137–142, 1966, doi: 10.1109/TCT.1966.1082556.
[35] S. P. Voinigescu, M. C. Maliepaard, J. L. Showell, G. E. Babcock, D. Marchesan, M. Schroter, P. Schvan, and D. L. Harame, "A scalable high-frequency noise model for bipolar transistors with application to optimal transistor sizing for low-noise amplifier design," IEEE Journal of Solid-State Circuits, vol. 32, no. 9, pp. 1430–1439, 1997, doi: 10.1109/4.628757.
[36] H. Rothe and W. Dahlke, "Theory of Noisy Fourpoles," Proceedings of the IRE, vol. 44, no. 6, pp. 811–818, 1956, doi: 10.1109/JRPROC.1956.274998.
[37] J. M. Cusack, S. M. Perlow, and B. S. Perlman, "Automatic Load Contour Mapping for Microwave Power Transistors," IEEE Transactions on Microwave Theory and Techniques, vol. 22, no. 12, pp. 1146–1152, 1974, doi: 10.1109/TMTT.1974.1128456.
[38] R. Q. Lane, "The determination of device noise parameters," Proceedings of the IEEE, vol. 57, no. 8, pp. 1461–1462, 1969, doi: 10.1109/PROC.1969.7311.
[39] M. Sannino, "On the determination of device noise and gain parameters," Proceedings of the IEEE, vol. 67, no. 9, pp. 1364–1366, 1979, doi: 10.1109/PROC.1979.11458.
[40] N. Nguyen, K. Phan, S. Lee, and C. Huynh, "A 35–37 GHz MMIC GaN Low Noise Amplifier," in 2021 International Symposium on Electrical and Electronics Engineering (ISEE), 15–16 April 2021, pp. 26–29, doi: 10.1109/ISEE51682.2021.9418772.
[41] J. Tai, J. Wong, and J.-S. Moon, "Ultra-Low Noise Figure Ka-Band MMIC LNA With Graded-Channel GaN HEMTs," Electronics Letters, vol. 61, no. 1, p. e70258, 2025, doi: 10.1049/ell2.70258.
[42] K. B. Niclas, "The Exact Noise Figure of Amplifiers with Parallel Feedback and Lossy Matching Circuits," IEEE Transactions on Microwave Theory and Techniques, vol. 30, no. 5, pp. 832–835, 1982, doi: 10.1109/TMTT.1982.1131150.
[43] M. Rudolph, N. Chaturvedi, K. Hirche, J. Wurfl, W. Heinrich, and G. Trankle, "Highly Rugged 30 GHz GaN Low-Noise Amplifiers," IEEE Microwave and Wireless Components Letters, vol. 19, no. 4, pp. 251–253, 2009, doi: 10.1109/LMWC.2009.2015514.
[44] M. Sato, Y. Niida, Y. Kamada, S. Ozaki, T. Ohki, K. Makiyama, N. Okamoto, and K. Joshin, "Q-Band InAlGaN/GaN LNA using current reuse topology," in 2016 IEEE MTT-S International Microwave Symposium (IMS), 22–27 May 2016, pp. 1–4, doi: 10.1109/MWSYM.2016.7540307.
[45] N. N. Xuan, H. N. Huy, and M. L. Duy, "Design of a Ka-band MMIC Low Noise Amplifier for 5G applications," in 2021 8th NAFOSTED Conference on Information and Computer Science (NICS), 21–22 Dec. 2021, pp. 420–423, doi: 10.1109/NICS54270.2021.9701480.
[46] M. Sabzi and A. Medi, "Analysis and design of multi-stage wideband LNA using simultaneously noise and impedance matching method," Microelectronics Journal, vol. 86, pp. 97–104, 2019, doi: 10.1016/j.mejo.2019.03.004.
[47] C. T. Fu, C. N. Kuo, and S. S. Taylor, "Low-Noise Amplifier Design With Dual Reactive Feedback for Broadband Simultaneous Noise and Impedance Matching," IEEE Transactions on Microwave Theory and Techniques, vol. 58, no. 4, pp. 795–806, 2010, doi: 10.1109/TMTT.2010.2041570.
[48] A. M. E. Abounemra, "Design of a Ka-Band LNA Based on 150 nm GaN-on-Si Technology," in 2023 International Microwave and Antenna Symposium (IMAS), 7–9 Feb. 2023, pp. 123–126, doi: 10.1109/IMAS55807.2023.10066882.