A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network
This article introduces a current-mode multiphase digital transmitter with a single-footprint transformer-based asymmetric Doherty output network. The proposed multiphase architecture overcomes the bandwidth expansion associated with the polar power amplifier (PA), while still achieving relatively c...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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IEEE
2023-01-01
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| Series: | IEEE Open Journal of the Solid-State Circuits Society |
| Subjects: | |
| Online Access: | https://ieeexplore.ieee.org/document/10167796/ |
| _version_ | 1797197377780580352 |
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| author | Jay R. Sheth Linsheng Zhang Xiaochuan Shen Vinay Iyer Steven M. Bowers |
| author_facet | Jay R. Sheth Linsheng Zhang Xiaochuan Shen Vinay Iyer Steven M. Bowers |
| author_sort | Jay R. Sheth |
| collection | DOAJ |
| description | This article introduces a current-mode multiphase digital transmitter with a single-footprint transformer-based asymmetric Doherty output network. The proposed multiphase architecture overcomes the bandwidth expansion associated with the polar power amplifier (PA), while still achieving relatively constant output power and drain efficiency (DE) profiles. Additionally, to achieve efficiency enhancement in deep power back-off (PBO), and to simultaneously achieve a compact form factor, an asymmetric series Doherty output matching network using a transformer-within-transformer structure is also proposed. A proof-of-concept eight-phase digital transmitter using the proposed single-footprint Doherty network is implemented in a general-purpose 65-nm CMOS process. The transmitter achieves more than 20-dBm output power <inline-formula> <tex-math notation="LaTeX">$(P_{\mathrm{ out}})$ </tex-math></inline-formula> and more than 31% DE from 4.5 to 6.7 GHz. At 8-dB PBO, it achieves a DE of 23% and 24% at 6.5 and 7.0 GHz, which corresponds to a <inline-formula> <tex-math notation="LaTeX">$1.76\times $ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$1.93\times $ </tex-math></inline-formula> improvement compared to normalized class B PA, respectively. The transmitter also achieves a 21% DE and an average <inline-formula> <tex-math notation="LaTeX">$P_{\mathrm{ out}}$ </tex-math></inline-formula> of 14 dBm with an r.m.s. error vector magnitude <inline-formula> <tex-math notation="LaTeX">$({\mathrm{ EVM}}_{\mathrm{ rms}})$ </tex-math></inline-formula> of 4.1% for a 20-MSym/s 64-quadrature amplitude modulation waveform at 6.5 GHz. |
| first_indexed | 2024-04-24T06:43:00Z |
| format | Article |
| id | doaj.art-2500152f1b0642eca9c1390e1dc7b119 |
| institution | Directory Open Access Journal |
| issn | 2644-1349 |
| language | English |
| last_indexed | 2024-04-24T06:43:00Z |
| publishDate | 2023-01-01 |
| publisher | IEEE |
| record_format | Article |
| series | IEEE Open Journal of the Solid-State Circuits Society |
| spelling | doaj.art-2500152f1b0642eca9c1390e1dc7b1192024-04-22T20:40:02ZengIEEEIEEE Open Journal of the Solid-State Circuits Society2644-13492023-01-01310311710.1109/OJSSCS.2023.329055010167796A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output NetworkJay R. Sheth0https://orcid.org/0000-0003-2891-6371Linsheng Zhang1https://orcid.org/0000-0002-5985-9819Xiaochuan Shen2Vinay Iyer3https://orcid.org/0000-0002-2150-5513Steven M. Bowers4https://orcid.org/0000-0002-4243-8663Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USADepartment of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USADepartment of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USADepartment of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USADepartment of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USAThis article introduces a current-mode multiphase digital transmitter with a single-footprint transformer-based asymmetric Doherty output network. The proposed multiphase architecture overcomes the bandwidth expansion associated with the polar power amplifier (PA), while still achieving relatively constant output power and drain efficiency (DE) profiles. Additionally, to achieve efficiency enhancement in deep power back-off (PBO), and to simultaneously achieve a compact form factor, an asymmetric series Doherty output matching network using a transformer-within-transformer structure is also proposed. A proof-of-concept eight-phase digital transmitter using the proposed single-footprint Doherty network is implemented in a general-purpose 65-nm CMOS process. The transmitter achieves more than 20-dBm output power <inline-formula> <tex-math notation="LaTeX">$(P_{\mathrm{ out}})$ </tex-math></inline-formula> and more than 31% DE from 4.5 to 6.7 GHz. At 8-dB PBO, it achieves a DE of 23% and 24% at 6.5 and 7.0 GHz, which corresponds to a <inline-formula> <tex-math notation="LaTeX">$1.76\times $ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$1.93\times $ </tex-math></inline-formula> improvement compared to normalized class B PA, respectively. The transmitter also achieves a 21% DE and an average <inline-formula> <tex-math notation="LaTeX">$P_{\mathrm{ out}}$ </tex-math></inline-formula> of 14 dBm with an r.m.s. error vector magnitude <inline-formula> <tex-math notation="LaTeX">$({\mathrm{ EVM}}_{\mathrm{ rms}})$ </tex-math></inline-formula> of 4.1% for a 20-MSym/s 64-quadrature amplitude modulation waveform at 6.5 GHz.https://ieeexplore.ieee.org/document/10167796/Asymmetric Doherty power amplifier (PA)CMOS PAdigital transmittermultiphase PApoly-phase filter (PPF)ring oscillator |
| spellingShingle | Jay R. Sheth Linsheng Zhang Xiaochuan Shen Vinay Iyer Steven M. Bowers A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network IEEE Open Journal of the Solid-State Circuits Society Asymmetric Doherty power amplifier (PA) CMOS PA digital transmitter multiphase PA poly-phase filter (PPF) ring oscillator |
| title | A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network |
| title_full | A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network |
| title_fullStr | A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network |
| title_full_unstemmed | A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network |
| title_short | A Current-Mode Multiphase Digital Transmitter With a Single-Footprint Transformer-Based Asymmetric Doherty Output Network |
| title_sort | current mode multiphase digital transmitter with a single footprint transformer based asymmetric doherty output network |
| topic | Asymmetric Doherty power amplifier (PA) CMOS PA digital transmitter multiphase PA poly-phase filter (PPF) ring oscillator |
| url | https://ieeexplore.ieee.org/document/10167796/ |
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