Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier
While an ideal Doherty power amplifier has a linear response, the load modulated balanced amplifier (LMBA) has a compressive response under ideal conditions. This inherent nonlinear characteristic is due to the lower power contribution of the single auxiliary device as the balanced amplifier transis...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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The Korean Institute of Electromagnetic Engineering and Science
2023-05-01
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| Series: | Journal of Electromagnetic Engineering and Science |
| Subjects: | |
| Online Access: | https://www.jees.kr/upload/pdf/jees-2023-3-r-170.pdf |
| _version_ | 1797692779594252288 |
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| author | Sagini E. Mochumbe Youngoo Yang |
| author_facet | Sagini E. Mochumbe Youngoo Yang |
| author_sort | Sagini E. Mochumbe |
| collection | DOAJ |
| description | While an ideal Doherty power amplifier has a linear response, the load modulated balanced amplifier (LMBA) has a compressive response under ideal conditions. This inherent nonlinear characteristic is due to the lower power contribution of the single auxiliary device as the balanced amplifier transistors approach compression. This article presents an LMBA with a two-stage control signal amplifier in place of the single auxiliary device. The idea is to preserve a high and constant gain across the high- and low-power regions by tuning the two-stage gain control signal to match the balanced amplifier gain. An optimal load trajectory can be found for a high-efficiency design by appropriately terminating the second harmonic while ensuring an optimal impedance match in all devices. At the same time, by setting an optimal output power from the auxiliary device, sufficient power is provided to linearize the response of the main power amplifier beyond the output back-off power boundary. As proof of concept, a prototype is designed and implemented. The experimental measurements demonstrate a drain efficiency of 59%–64% at maximum output power and 46%–52% at 7.5 dB output back-off power over the target frequency range of 3.3–3.8 GHz. |
| first_indexed | 2024-03-12T02:33:30Z |
| format | Article |
| id | doaj.art-19bba49207a849848684bcd073dd4a68 |
| institution | Directory Open Access Journal |
| issn | 2671-7255 2671-7263 |
| language | English |
| last_indexed | 2024-03-12T02:33:30Z |
| publishDate | 2023-05-01 |
| publisher | The Korean Institute of Electromagnetic Engineering and Science |
| record_format | Article |
| series | Journal of Electromagnetic Engineering and Science |
| spelling | doaj.art-19bba49207a849848684bcd073dd4a682023-09-05T02:15:35ZengThe Korean Institute of Electromagnetic Engineering and ScienceJournal of Electromagnetic Engineering and Science2671-72552671-72632023-05-0123329430110.26866/jees.2023.3.r.1703599Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power AmplifierSagini E. Mochumbe0Youngoo Yang1Department of Electrical and Computer Engineering, College of Information and Communication Engineering, Sungkyunkwan University, Suwon, KoreaDepartment of Electrical and Computer Engineering, College of Information and Communication Engineering, Sungkyunkwan University, Suwon, KoreaWhile an ideal Doherty power amplifier has a linear response, the load modulated balanced amplifier (LMBA) has a compressive response under ideal conditions. This inherent nonlinear characteristic is due to the lower power contribution of the single auxiliary device as the balanced amplifier transistors approach compression. This article presents an LMBA with a two-stage control signal amplifier in place of the single auxiliary device. The idea is to preserve a high and constant gain across the high- and low-power regions by tuning the two-stage gain control signal to match the balanced amplifier gain. An optimal load trajectory can be found for a high-efficiency design by appropriately terminating the second harmonic while ensuring an optimal impedance match in all devices. At the same time, by setting an optimal output power from the auxiliary device, sufficient power is provided to linearize the response of the main power amplifier beyond the output back-off power boundary. As proof of concept, a prototype is designed and implemented. The experimental measurements demonstrate a drain efficiency of 59%–64% at maximum output power and 46%–52% at 7.5 dB output back-off power over the target frequency range of 3.3–3.8 GHz.https://www.jees.kr/upload/pdf/jees-2023-3-r-170.pdfload modulated balanced amplifierload modulationpower amplifiertwo-stage control signal |
| spellingShingle | Sagini E. Mochumbe Youngoo Yang Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier Journal of Electromagnetic Engineering and Science load modulated balanced amplifier load modulation power amplifier two-stage control signal |
| title | Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier |
| title_full | Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier |
| title_fullStr | Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier |
| title_full_unstemmed | Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier |
| title_short | Design of a Load Modulated Balanced Amplifier with a Two-Stage Control Power Amplifier |
| title_sort | design of a load modulated balanced amplifier with a two stage control power amplifier |
| topic | load modulated balanced amplifier load modulation power amplifier two-stage control signal |
| url | https://www.jees.kr/upload/pdf/jees-2023-3-r-170.pdf |
| work_keys_str_mv | AT saginiemochumbe designofaloadmodulatedbalancedamplifierwithatwostagecontrolpoweramplifier AT youngooyang designofaloadmodulatedbalancedamplifierwithatwostagecontrolpoweramplifier |