Paper Info
Title
Complex Bandpass Delta Sigma Ad Modulator Architecture Without I, Q-Path Crossing Layout
Abstract
This paper proposes a new architecture for multibit complex bandpass Delta Sigma AD modulators with built-in Switched-Capacitor (SC) circuits for application to Low-IF receivers such as used for Bluetooth and WLAN. In the realization of complex bandpass Delta Sigma AD modulators, we face the following problems: (i) SNR of AD converter is deteriorated by mismatches between internal analog I and Q paths. (ii) Layout design becomes complicated because of signal lines crossing by complex filter and feedback from DAC for I and Q paths in the complex modulator, and this increases required chip area. We propose a new structure for a complex bandpass Delta Sigma AD modulator which can be completely divided into two paths without layout crossing, and solves the problems mentioned above. The two parts of signal paths and circuits in the modulator are changed for I and Q while CLK is changed for High/Low by adding multiplexers. Symmetric circuits are used for I and Q paths at a certain timing, and they are switched by multiplexers to those used for Q and I paths at another timing. Therefore the influence from mismatches between I and Q paths is reduced by dynamic matching. As a result, the modulator is divided into two separate parts without crossing signal lines between I and Q paths and its layout design can be greatly simplified compared with conventional modulators. We have conducted MATLAB simulations to confirm the effectiveness of the proposed structure.
Year
DOI
Venue
2006
10.1093/ietfec/e89-a.4.908
IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES
Keywords
DocType
Volume
complex bandpass Delta Sigma AD modulator I, Q path mismatches, dynamic matching, multiplexer
Journal
E89A
Issue
ISSN
Citations 
4
0916-8508
0
PageRank 
References 
Authors
0.34
0
15
Name
Order
Citations
PageRank
Hao San14116.68
Akira Hayakawa221.97
Yoshitaka Jingu321.63
Hiroki Wada4263.83
Hiroyuki Hagiwara521.63
Kazuyuki Kobayashi66011.04
Haruo Kobayashi7277.46
Tatsuji Matsuura8278.16
Kouichi Yahagi921.29
Junya Kudoh1073.77
Hideo Nakane1121.29
Masao Hotta12309.59
Toshiro Tsukada13204.74
Koichiro Mashiko1422.31
Atsushi Wada1522.31