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Title:
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A CMOS VGA with DC offset cancellation for direct-conversion receivers.
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Author:
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Zheng, Yuanjin.; Yan, Jiangnan.; Xu, Yong Ping.
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Copyright year:
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2009 |
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Abstract:
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A CMOS dB-linear variable gain amplifier (VGA)
with a novel I/Q tuning loop for dc-offset cancellation is presented.
The CMOS dB-linear VGA provides a variable gain of 60 dB while
maintaining its 3-dB bandwidth greater than 2.5 MHz. A novel
exponential circuit is proposed to obtain the dB-linear gain control
characteristics. Nonideal effects on dB linearity are analyzed and
the methods for improvement are suggested. A varying-bandwidth
LPF is employed to achieve fast settling. The chip is fabricated
in a 0.35-µm CMOS technology and the measurement results
demonstrate the good dB linearity of the proposed VGA and show
that the tuning loop can effectively remove dc offset and suppress
I/Q mismatch effects simultaneously. |
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Subject:
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DRNTU::Engineering::Electrical and electronic engineering. |
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Type:
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Journal Article |
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Series/ Journal Title:
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IEEE transactions on circuits and systems—I |
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School:
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School of Electrical and Electronic Engineering |
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Rights:
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© 2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. http://www.ieee.org/portal/site This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder. |
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Version:
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Published version |
