本論文第一部分採用WIN 0.12 μm GaN HEMT 製程，實現一款應用於 28 GHz 頻段之功率放大器。電路採用二級放大架構，設計過程中首先利用 load-pull 分析，求得電晶體於目標頻率下之最佳輸出負載阻抗，並以此作為匹配網路之設計基礎。模擬結果顯示，於 28 GHz 操作頻率下，所提出之功率放大器可達到 22.1 dB 的小訊號增益，34.3 dBm 的輸出功率，以及 22% 的最大功率附加效率，實際使用晶片面積為 1.7 × 1.7 mm²。此功率放大器分別採用 on-wafer 與 chip-mounted-on-PCB 兩種方式進行量測。第一次 on-wafer 量測結果顯示，小訊號增益為 19.5 dB，輸出功率為 31.8 dBm，最大功率附加效率為 17.3%。第二次採用 chip-mounted-on-PCB 方式量測時，小訊號增益提升至 21.1 dB、輸出功率達 33.2 dBm，最大功率附加效率為 22.9%。
第二部分同樣使用WIN 0.12 μm GaN HEMT 製程實現一顆 Ku/Ka 頻段併發雙頻放大器。為同時支援不同頻段操作需求，電路採用上下兩路功率放大器架構，分別對應 Ku 與 Ka 頻段，並經由合波網路完成輸出整合。透過各路徑獨立匹配設計，使電路於兩個頻段下皆能維持良好的增益、輸出功率與穩定性。模擬結果顯示，於 15 GHz 與 28 GHz 操作頻率下，小訊號增益分別為 22 dB 與 19 dB，輸出功率皆大於33 dBm，最大功率附加效率分別23%與19%，實際使用晶片面積為 2.7*1.7 mm²。量測結果顯示，在 15 GHz 和大約 27.4 GHz 時，所製造的 PA 分別實現了 20.5 dB 和 15.2 dB 的測量增益、超過 32 dBm 和 31 dBm 的輸出功率以及 30.8% 和 19.5% 的最大 PAE。
第三部分使用WIN GaN 0.12 μm HEMT 製程設計雙刀雙擲（DPDT）射頻開關電路。電路採用傳統背對背架構，以形成對稱訊號路徑並改善高頻操作下之隔離與插入損耗表現。藉由適當調整開關元件尺寸與偏壓條件，使開關在目標頻率下兼具良好的傳輸特性與隔離能力。模擬結果顯示，於 21.9~30.9 GHz 操作頻率下，插入損耗約為3.4 - 4 dB，隔離度可達30 dB，回波損耗優於10 dB，實際使用晶片面積為1.2*1.2 mm²。

The first part of this thesis presents a 28-GHz power amplifier (PA) implemented using the WIN 0.12-μm GaN HEMT process. A two-stage amplifier architecture is adopted. During the design process, load-pull analysis is first performed to determine the optimum load impedance of the transistor at the target frequency, which serves as the basis for the matching-network design. Simulation results show that, at 28 GHz, the proposed PA achieves a small-signal gain of 22.1 dB, an output power of 34.3 dBm, and a maximum PAE of 22%, with core chip area of 1.7 × 1.7 mm². The fabricated PA is characterized using both on-wafer and chip-mounted-on-PCB measurement configurations. The on-wafer measurement results show a small-signal gain of 19.5 dB, an output power of 31.8 dBm, and a maximum PAE of 17.3%. In the chip-mounted-on-PCB measurements, the PA achieves a small-signal gain of 21.1 dB, an output power of 33.2 dBm, and a maximum PAE of 22.9%.
The second part of this thesis presents a concurrent dual-band power amplifier (PA) operating in the Ku- and Ka-band, implemented using the WIN 0.12-μm GaN HEMT process. To simultaneously support operation at two frequency bands, the proposed circuit adopts a dual-path architecture, in which the upper and lower amplifier paths are designed for the Ka- and Ku-band, respectively. The outputs of the two amplifier paths are combined through an output combining network. By independently optimizing the matching networks for each signal path, the proposed PA achieves satisfactory gain, output power, and stability in both operating bands. Simulation results show that, at 15 GHz and 28 GHz, the proposed PA achieves small-signal gains of 22 dB and 19 dB, output powers exceeding 33 dBm in both bands, and maximum PAEs of 23% and 19%, respectively, with core chip area of 2.7 × 1.7 mm². Measurement results demonstrate that, at 15 GHz and approximately 27.4 GHz, the fabricated PA achieves measured gains of 20.5 dB and 15.2 dB, output powers exceeding 32 dBm and 31 dBm, and maximum PAEs of 30.8% and 19.5%, respectively.
The third part of this thesis presents a double-pole double-throw (DPDT) RF switch implemented using WIN 0.12-μm GaN HEMT process. The proposed switch adopts a conventional back-to-back topology to provide a symmetrical signal path while improving isolation and insertion loss performance at high frequencies. By appropriately optimizing the dimensions of the switching transistors and the bias conditions, the proposed switch achieves favorable transmission characteristics and high isolation over the target frequency range. Simulation results show that, over the frequency range of 21.9–30.9 GHz, the proposed DPDT switch exhibits an insertion loss of 3.4–4.0 dB, an isolation greater than 30 dB, and a return loss better than 10 dB, with core chip area of 1.2 × 1.2 mm².

[1] C. J. Zhang et al., "Key technology for 5G new radio," IEEE Communications Magazine, vol. 56, no. 3, pp. 10–11, 2018.
[2] P. M. Asbeck, N. Rostomyan, M. Özen, B. Rabet, and J. A. Jayamon, "Power amplifiers for mm-wave 5G applications: Technology comparisons and CMOS-SOI demonstration circuits," IEEE Transactions on Microwave Theory and Techniques, vol. 67, no. 7, pp. 3099–3109, 2019.
[3] A. Ghiotto, E. Kerhervé, N. Demirel, A. Larie, P. Garrec, and Y. Mancuso, "Dual-mode power amplifier module with in-band reconfigurable output power for multifunctional radar and radio communication systems," in 2014 International Radar Conference, 2014: IEEE, pp. 1–3.
[4] V. Camarchia, R. Quaglia, A. Piacibello, D. P. Nguyen, H. Wang, and A.-V. Pham, "A review of technologies and design techniques of millimeter-wave power amplifiers," IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 7, pp. 2957–2983, 2020.
[5] K. Nakatani, Y. Yamaguchi, T. Trii, A. Hirai, and K. Kanava, "Ka-band high efficiency and high linearity GaN power amplifiers for broadband high throughput satellite communication systems," in 2024 IEEE Asia-Pacific Microwave Conference (APMC), 2024: IEEE, pp. 614–616.
[6] A. Inoue, "Millimeter-wave GaN devices for 5G: Massive MIMO antenna arrays for sub-6-GHz and mm-wave bandwidth," IEEE Microwave Magazine, vol. 22, no. 5, pp. 100–110, 2021.
[7] B. Razavi and R. Behzad, RF microelectronics. Prentice hall New York, 2012.
[8] K. Kohama, T. Ohgihara, and Y. Murakami, "High power DPDT antenna switch MMIC for digital cellular systems," IEEE Journal of Solid-State Circuits, vol. 31, no. 10, pp. 1406–1411, 1996.
[9] S. C. Cripps, RF power amplifiers for wireless communications. Artech house Norwood, MA, 2006.
[10] R. W. Jackson, "Rollett proviso in the stability of linear microwave circuits—A tutorial," IEEE Transactions on Microwave Theory and Techniques, vol. 54, no. 3, pp. 993–1000, 2006.
[11] L. Samoska et al., "On the stability of millimeter-wave power amplifiers," in 2002 IEEE MTT-S International Microwave Symposium Digest (Cat. No. 02CH37278), 2002, vol. 1: IEEE, pp. 429–432.
[12] A. Anakabe, J. Collantes, J. Portilla, S. Mons, and A. Mallet, "Detecting and avoiding odd‐mode parametric oscillations in microwave power amplifiers," International Journal of RF and Microwave Computer‐Aided Engineering: Co‐sponsored by the Center for Advanced Manufacturing and Packaging of Microwave, Optical, and Digital Electronics (CAMPmode) at the University of Colorado at Boulder, vol. 15, no. 5, pp. 469–478, 2005.
[13] 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.
[14] K. Hayat, S. Zafar, T. Mehmood, B. Cankaya Akoglu, E. Ozbay, and A. Kashif, "Eighty nine‐watt cascaded multistage power amplifier using gallium nitride‐on‐silicon high electron mobility transistor for L‐band radar applications," IET Circuits, Devices & Systems, vol. 15, no. 8, pp. 830–841, 2021.
[15] T. T. Nguyen, K. Fujii, and A. V. Pham, "A 4–20 GHz, multi‐watt level, fully integrated push–pull distributed power amplifier with wideband even‐order harmonic suppression," IET Microwaves, Antennas & Propagation, vol. 13, no. 13, pp. 2279–2283, 2019.
[16] A. Jundi and S. Boumaiza, "A series-connected-load Doherty power amplifier with push–pull main and auxiliary amplifiers for base station applications," IEEE Transactions on Microwave Theory and Techniques, vol. 68, no. 2, pp. 796–807, 2019.
[17] S. Gielen, B. Gungor, Y. Zhang, M. Ingels, and P. Reynaert, "Design and Implementation of a D-Band Guanella Transformer-Based Stacked Doherty Power Amplifier in 250-nm InP DHBT," IEEE Transactions on Microwave Theory and Techniques, 2026.
[18] M. M. Tarar, S. Qayyum, A. Ali, and R. Negra, "Loss-compensated cascaded multistage distributed power amplifier in 65Nm CMOS technology," IEEE Access, vol. 12, pp. 98917–98927, 2024.
[19] Z. Zong et al., "A 28-GHz SOI-CMOS Doherty power amplifier with a compact transformer-based output combiner," IEEE Transactions on Microwave Theory and Techniques, vol. 69, no. 6, pp. 2795–2808, 2021.
[20] H. Zhou, J.-R. Perez-Cisneros, S. Hesami, K. Buisman, and C. Fager, "A generic theory for design of efficient three-stage Doherty power amplifiers," IEEE transactions on microwave theory and techniques, vol. 70, no. 2, pp. 1242–1253, 2021.
[21] D. M. Pozar, Microwave engineering. John wiley & sons, 2011.
[22] A. Grebennikov, N. O. Sokal, and M. J. Franco, Switchmode RF and Microwave Power Amplifiers Ed. 2. Elsevier Science, 2012.
[23] L. Peng, S. Lin, J. Chen, J. Li, and G. Zhang, "Ka-band 1 W GaN MMIC power amplifier design," in 2021 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC), 2021: IEEE, pp. 01–04.
[24] M. R. Duffy, G. Lasser, G. Nevett, M. Roberg, and Z. Popović, "A three-stage 18.5–24-GHz GaN-on-SiC 4 W 40% efficient MMIC PA," IEEE Journal of Solid-State Circuits, vol. 54, no. 9, pp. 2402–2410, 2019.
[25] Y.-M. Chen, L.-Y. Lee, T.-H. Chen, C.-S. Wu, and H. Wang, "A Ka-band High-OP 1dB Power Amplifier in 0.15-μm GaN Process for 5G Base Station and Satellite Communications Applications," in 2022 Asia-Pacific Microwave Conference (APMC), 2022: IEEE, pp. 593–595.
[26] Q. Cai, H. Zhu, D. Zeng, Q. Xue, and W. Che, "A Three-Stage Wideband GaN PA for 5G mm-Wave Applications," IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 69, no. 12, pp. 4724–4728, 2022, doi: 10.1109/TCSII.2022.3206824.
[27] H. Tao et al., "High-Power Ka/Ku Dual-Wideband GaN Power Amplifier With High Input Isolation and Transformer-Combined Load Design," IEEE Microwave and Wireless Components Letters, vol. 31, no. 1, pp. 49–51, 2021, doi: 10.1109/LMWC.2020.3032569.
[28] F. Yu, C. Jin, J. Huang, and Z. Wang, "Design of X/Ku Dual-Wideband GaN Power Amplifier MMIC Based on Coupled Multiresonator Matching Networks," IEEE Transactions on Circuits and Systems II: Express Briefs, vol. 70, no. 2, pp. 786–790, 2023, doi: 10.1109/TCSII.2022.3163178.
[29] C. Xie, P. Wu, C. Tan, Y. Yuan, J. Zeng, and Z. Yu, "An X/Ku Dual-Band Switchless Frequency Reconfigurable GaAs Power Amplifier," IEEE Microwave and Wireless Components Letters, vol. 32, no. 6, pp. 539–542, 2022, doi: 10.1109/LMWC.2021.3139665.
[30] K. Choi, H. Park, M. Kim, J. Kim, and Y. Kwon, "A 6–18-GHz Switchless Reconfigurable Dual-Band Dual-Mode PA MMIC Using Coupled-Line-Based Diplexer," IEEE Transactions on Microwave Theory and Techniques, vol. 66, no. 12, pp. 5685–5695, 2018, doi: 10.1109/TMTT.2018.2879356.
[31] S. Chakraborty and T. Xia, "28/39 GHz Dual-Band GaN Power Amplifier Design," in 2025 IEEE International Symposium on Circuits and Systems (ISCAS), 25–28 May 2025 2025, pp. 1–5, doi: 10.1109/ISCAS56072.2025.11043845.
[32] T. S. Rappaport et al., "Millimeter Wave Mobile Communications for 5G Cellular: It Will Work!," IEEE Access, vol. 1, pp. 335–349, 2013, doi: 10.1109/ACCESS.2013.2260813.
[33] S. F. Chao, H. Wang, C. Y. Su, and J. G. J. Chern, "A 50 to 94-GHz CMOS SPDT Switch Using Traveling-Wave Concept," IEEE Microwave and Wireless Components Letters, vol. 17, no. 2, pp. 130–132, 2007, doi: 10.1109/LMWC.2006.890339.
[34] M. Uzunkol and G. Rebeiz, "A Low-Loss 50–70 GHz SPDT Switch in 90 nm CMOS," IEEE Journal of Solid-State Circuits, vol. 45, no. 10, pp. 2003–2007, 2010, doi: 10.1109/JSSC.2010.2057950.
[35] X. Tang et al., "Design and Analysis of a 28 GHz T/R Front-End Module in 22-nm FD-SOI CMOS Technology," IEEE Transactions on Microwave Theory and Techniques, vol. 69, no. 6, pp. 2841–2853, 2021, doi: 10.1109/TMTT.2021.3059891.
[36] S. Shinjo et al., "A 28GHz-band highly integrated GaAs RF frontend Module for Massive MIMO in 5G," in 2018 IEEE MTT-S International Microwave Workshop Series on 5G Hardware and System Technologies (IMWS-5G), 30–31 Aug. 2018 2018, pp. 1–3, doi: 10.1109/IMWS-5G.2018.8484564.
[37] D. Zeng et al., "A Compact 24–30-GHz GaN Front-End Module With Coupled-Resonator-Based Transmit/Receive Switch for 5G Millimeter-Wave Applications," IEEE Transactions on Microwave Theory and Techniques, vol. 73, no. 4, pp. 1938–1950, 2025, doi: 10.1109/TMTT.2025.3530435.
[38] D. Palombini, A. Bentini, and D. Rampazzo, "A 6–18 GHz integrated HPA-DPDT GaN MMIC," in 2016 IEEE MTT-S International Microwave Symposium (IMS), 22–27 May 2016 2016, pp. 1–4, doi: 10.1109/MWSYM.2016.7540152.
[39] Y. A. Lin, C. Y. Chan, H. E. Liu, J. J. Huang, and H. Y. Chang, "A low loss high isolation double-pole double-throw traveling-wave switch using 0.5-μm GaAs process," in 2017 Progress in Electromagnetics Research Symposium - Fall (PIERS - FALL), 19–22 Nov. 2017 2017, pp. 2001–2005, doi: 10.1109/PIERS-FALL.2017.8293466.
[40] H. Song, Y. Wu, and H. Wei, "A DC-12GHz DPDT Switch Matrix MMIC in GaAs E/D-Mode PHEMT Technology," in 2022 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 12–15 Aug. 2022 2022, pp. 1–3, doi: 10.1109/ICMMT55580.2022.10023347.