In this study, we present a high-power back-off (PBO) efficiency asymmetric Doherty power amplifier (Doherty PA), featuring compact transformer-based input/output matching networks. The series output combiner, meticulously designed for asymmetric power ratio synthesis, integrates impedance inverters into the power combiner. This design significantly boosts power additional efficiency within a 9-dB PBO range. The integration of a quarter-wavelength phase compensation circuit and a quadrature power divider, both designed based on transformer structure, effectively minimizes the core chip area. Furthermore, the incorporation of neutralizing capacitor technology within the cascode structure has significantly enhanced gain and stability. The designed Doherty PA is manufactured by 65 nm CMOS technology, achieving 23.2 dBm saturated output power (P_sat) with 28.2% peak power added efficiency (PAE), and 22.4 dBm 1-dB output compression point (OP_1dB) at 38 GHz. The measured PAE at 9-dB PBO efficiency is 16.1%. These figures result in an efficiency enhancement ratio of 1.78 when compared to an ideal class-B PA.

Open Research

Data Availability Statement

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

References

1B. Sadhu, X. Gu, and A. Valdes-Garcia, “The More (Antennas), the Merrier: A Survey of Silicon-Based mm-Wave Phased Arrays Using Multi-IC Scaling,” IEEE Microwave Magazine 20, no. 12 (2019): 32–50.
10.1109/MMM.2019.2941632
Web of Science® Google Scholar
2X. Fang, J. Xia, and S. Boumaiza, “A 28-GHz Beamforming Doherty Power Amplifier With Enhanced AM-PM Characteristic,” IEEE Transactions on Microwave Theory and Techniques 68, no. 7 (2020): 3017–3027.
10.1109/TMTT.2020.2968318
Web of Science® Google Scholar
3D. Zhao, P. Gu, J. Zhong, et al., “Millimeter-Wave Integrated Phased Arrays,” IEEE Transactions on Circuits and Systems I: Regular Papers 68, no. 10 (2021): 3977–3990.
10.1109/TCSI.2021.3093093
Web of Science® Google Scholar
4Y. Yi, D. Zhao, J. Zhang, et al., “A 24-29.5-GHz Highly Linear Phased-Array Transceiver Front-End in 65-nm Cmos Supporting 800-MHz 64-QAM and 400-MHz 256-QAM for 5G New Radio,” IEEE Journal of Solid-State Circuits 57, no. 9 (2022): 2702–2718.
10.1109/JSSC.2022.3169588
Web of Science® Google Scholar
5J. Xia, Z. Xie, W. Kong, R. Liu, and Z. Zhao, “A 9 dB Back-Off Dual-Band Asymmetric Doherty Power Amplifier Using Dual Peaking Amplifiers for Reactance Compensation,” Microwave and Optical Technology Letters 64, no. 7 (2022): 1145–1153.
10.1002/mop.33248
Web of Science® Google Scholar
6C. Yu, J. Feng, and D. Zhao, “A 28-GHz Doherty Power Amplifier With a Compact Transformer-Based Quadrature Hybrid in 65-nm CMOS,” IEEE Transactions on Circuits and Systems II: Express Briefs 68, no. 8 (2021): 2790–2794.
Web of Science® Google Scholar
7H. C. Park, S. Kim, J. Lee, et al., “Single Transformer-Based Compact Doherty Power Amplifiers for 5G RF Phased-Array ICs,” IEEE Journal of Solid-State Circuits 57, no. 5 (2022): 1267–1279.
10.1109/JSSC.2022.3148044
Web of Science® Google Scholar
8Y. C. Chen, Y. H. Lin, J. L. Lin, and H. Wang, “A Ka-Band Transformer-Based Doherty Power Amplifier for Multi-Gb/S Application in 90-nm CMOS,” IEEE Microwave and Wireless Components Letters 28, no. 12 (2018): 1134–1136.
10.1109/LMWC.2018.2878133
Web of Science® Google Scholar
9X. Zhang, S. Li, D. Huang, and T. Chi, “A 38GHz Deep Back-Off Efficiency Enhancement PA With Three-Way Doherty Network Synthesis Achieving 11.3 dBm Average Output Power and 14.7% Average Efficiency for 5G NR OFDM,” in Proceedings of the IEEE Radio Frequency Integrated Circuits (2022): 239–242.
Google Scholar
10N. Mannem, M. Huang, T. Huang, S. Li, and H. Wang, “ A Reconfigurable Series/Parallel Quadrature-Coupler-Based Doherty PA in CMOS SOI With VSWR Resilient Linearity and Back-Off PAE for 5G MIMO Arrays.” IEEE Int. Solid-State Circuits Conf. (ISSCC) Dig. Tech. Papers (2020), 364–366.
Google Scholar
11Z. Ma, Z. Ma, K. Ma, F. Meng, and K. Wang, “A 28-GHz 26.8-dBm Doherty Power Amplifier With Four-Way Differential Hybrid Load-Modulated Combiner in 55-nm CMOS,” IEEE Microwave and Wireless Technology Letters 33, no. 7 (2023): 1015–1018.
10.1109/LMWT.2023.3262602
Google Scholar
12W. Chen, Y. Wu, Y. Zheng, and W. Wang, “Broadband Asymmetric GaAs Mmic Doherty Power Amplifiers With Simplified Peaking Matching Network and Output Capacitance Compensation,” IEEE Microwave and Wireless Technology Letters 33, no. 8 (2023): 1195–1198.
10.1109/LMWT.2023.3279573
Google Scholar
13A. Grebennikov and J. Wong, “A Dual-Band Parallel Doherty Power Amplifier for Wireless Applications,” IEEE Transactions on Microwave Theory and Techniques 60, no. 10 (2012): 3214–3222.
10.1109/TMTT.2012.2210906
Web of Science® Google Scholar
14E. Kaymaksut and P. Reynaert, “Transformer-Based Uneven Doherty Power Amplifier in 90 nm CMOS for WLAN Applications,” IEEE Journal of Solid-State Circuits 47, no. 7 (2012): 1659–1671.
10.1109/JSSC.2012.2191334
Web of Science® Google Scholar
15D. Chen, C. Zhao, Z. Jiang, K. M. Shum, Q. Xue, and K. Kang, “A V-Band Doherty Power Amplifier Based on Voltage Combination and Balance Compensation Marchand Balun,” IEEE Access 6, no. 1 (2018): 10131–10138.
10.1109/ACCESS.2018.2795379
Google Scholar
16S. Chen, G. Wang, Z. Cheng, P. Qin, and Q. Xue, “Adaptively Biased 60-GHz Doherty Power Amplifier in 65-nm CMOS,” IEEE Microwave and Wireless Components Letters 27, no. 3 (2017): 296–298.
10.1109/LMWC.2017.2662011
Web of Science® Google Scholar
17H. Zhang, R. Z. Zhan, Y. C. Li, and J. Mou, “High Efficiency Doherty Power Amplifier Using Dual-Adaptive Biases,” IEEE Transactions on Circuits and Systems I: Regular Papers 67, no. 8 (2020): 2625–2634.
10.1109/TCSI.2020.2977770
Web of Science® Google Scholar
18T. H. Fan, Y. Wang, and H. Wang, “A Broadband Transformer-Based Power Amplifier Achieving 24.5-dBm Output Power over 24–41 GHz in 65-nm CMOS Process,” IEEE Microwave and Wireless Components Letters 31, no. 3 (2021): 308–311.
10.1109/LMWC.2020.3040786
Web of Science® Google Scholar
19Z. Zhong, X. Tang, K. Khalaf, et al., “A 28-GHz SOI-CMOS Doherty Power Amplifier With a Compact Transformer-Based Output Combiner,” IEEE Transactions on Microwave Theory and Techniques 60, no. 10 (2021): 3214–3222.
Google Scholar
20Y. Li, Z. Duan, Y. Fang, et al., “A 32–40 GHz 7-bit Bi-Directional Phase Shifter With 0.36 Db/1.6° RMS Magnitude/Phase Errors for Phased Array Systems,” IEEE Transactions on Circuits and Systems I: Regular Papers 69, no. 10 (2022): 4000–4013.
10.1109/TCSI.2022.3188157
Google Scholar

Volume67, Issue6

June 2025

e70260

An Asymmetric Cascode Doherty Power Amplifier With a Transformer-Based Combiner in 65-nm CMOS

ABSTRACT

Open Research

Data Availability Statement

References

References

Information

About Wiley Online Library

Help & Support

Opportunities

Connect with Wiley

An Asymmetric Cascode Doherty Power Amplifier With a Transformer-Based Combiner in 65-nm CMOS

ABSTRACT

Open Research

Data Availability Statement

References

References

Related

Information