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An active-under-coil RFDAC with analog linear interpolation in 28-nm CMOS

Zhang, Feifei ; Chen, Peng LU orcid ; Walling, Jeffrey S. ; Zhu, Anding and Staszewski, Robert Bogdan (2021) In IEEE Transactions on Circuits and Systems I: Regular Papers 68(5). p.1855-1868
Abstract

This paper demonstrates a wideband 2.4 GHz $2\times 9$ -bit Cartesian radio-frequency digital-to-analog converter (RFDAC). Active-under-coil integration is introduced in the physical implementation, where all key active circuitry is located underneath the matching-network transformer, achieving a core area of merely 0.35 mm2. An 8× analog linear interpolation at the RF rate is proposed to suppress replicas close to the carrier while avoiding any high-order and high-speed digital filters in digital processing back-end. The multi-port transformer is adopted in the matching network to improve the back-off efficiency. The measured peak output power and drain efficiency at the center frequency of 2.4 GHz are 17.47 dBm and 17.6% respectively,... (More)

This paper demonstrates a wideband 2.4 GHz $2\times 9$ -bit Cartesian radio-frequency digital-to-analog converter (RFDAC). Active-under-coil integration is introduced in the physical implementation, where all key active circuitry is located underneath the matching-network transformer, achieving a core area of merely 0.35 mm2. An 8× analog linear interpolation at the RF rate is proposed to suppress replicas close to the carrier while avoiding any high-order and high-speed digital filters in digital processing back-end. The multi-port transformer is adopted in the matching network to improve the back-off efficiency. The measured peak output power and drain efficiency at the center frequency of 2.4 GHz are 17.47 dBm and 17.6% respectively, while the peak efficiency is 19.03%. Moreover, the 6-dB back-off efficiency is at 66% of that at the peak output power. The active-under-coil integration helps this RFDAC to achieve the smallest area among comparable prior arts.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Active-under-coil integration, Analog linear interpolation (ALI), Class-E power amplifier, Multi-port transformer, RFDAC
in
IEEE Transactions on Circuits and Systems I: Regular Papers
volume
68
issue
5
article number
9361220
pages
14 pages
publisher
IEEE - Institute of Electrical and Electronics Engineers Inc.
external identifiers
  • scopus:85101778627
ISSN
1549-8328
DOI
10.1109/TCSI.2021.3059368
language
English
LU publication?
yes
additional info
Funding Information: Manuscript received June 4, 2020; revised November 3, 2020 and January 18, 2021; accepted February 7, 2021. Date of publication February 23, 2021; date of current version April 27, 2021. This work was supported by the Microelectronic Circuits Centre Ireland (MCCI) through Enterprise Ireland under Grant TC-2015-0019. This article was recommended by Associate Editor H. Stratigopoulos. (Corresponding author: Peng Chen.) Feifei Zhang was with MCCI, Dublin D04, Ireland, and also with the School of Electrical and Electronic Engineering, University College Dublin, Dublin D04, Ireland. She is now with Silicon Austria Labs, 4040 Linz, Austria (e-mail: feifei.zhang@silicon-austria.com). Publisher Copyright: © 2004-2012 IEEE.
id
cabee699-2fcf-4534-a1a9-53e7b9020bf2
date added to LUP
2023-09-29 14:14:11
date last changed
2023-10-18 14:50:38
@article{cabee699-2fcf-4534-a1a9-53e7b9020bf2,
  abstract     = {{<p>This paper demonstrates a wideband 2.4 GHz $2\times 9$ -bit Cartesian radio-frequency digital-to-analog converter (RFDAC). Active-under-coil integration is introduced in the physical implementation, where all key active circuitry is located underneath the matching-network transformer, achieving a core area of merely 0.35 mm2. An 8× analog linear interpolation at the RF rate is proposed to suppress replicas close to the carrier while avoiding any high-order and high-speed digital filters in digital processing back-end. The multi-port transformer is adopted in the matching network to improve the back-off efficiency. The measured peak output power and drain efficiency at the center frequency of 2.4 GHz are 17.47 dBm and 17.6% respectively, while the peak efficiency is 19.03%. Moreover, the 6-dB back-off efficiency is at 66% of that at the peak output power. The active-under-coil integration helps this RFDAC to achieve the smallest area among comparable prior arts.</p>}},
  author       = {{Zhang, Feifei and Chen, Peng and Walling, Jeffrey S. and Zhu, Anding and Staszewski, Robert Bogdan}},
  issn         = {{1549-8328}},
  keywords     = {{Active-under-coil integration; Analog linear interpolation (ALI); Class-E power amplifier; Multi-port transformer; RFDAC}},
  language     = {{eng}},
  number       = {{5}},
  pages        = {{1855--1868}},
  publisher    = {{IEEE - Institute of Electrical and Electronics Engineers Inc.}},
  series       = {{IEEE Transactions on Circuits and Systems I: Regular Papers}},
  title        = {{An active-under-coil RFDAC with analog linear interpolation in 28-nm CMOS}},
  url          = {{http://dx.doi.org/10.1109/TCSI.2021.3059368}},
  doi          = {{10.1109/TCSI.2021.3059368}},
  volume       = {{68}},
  year         = {{2021}},
}