J4 ›› 2013, Vol. 40 ›› Issue (3): 27-35.doi: 10.3969/j.issn.1001-2400.2013.03.005

• Original Articles • Previous Articles     Next Articles

Novel adaptive method based on the Taylor series to  compensate channel-mismatches of TIADC

WANG Yajun;LI Ming   

  1. (National Key Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2012-01-01 Online:2013-06-20 Published:2013-07-29
  • Contact: WANG Yajun E-mail:jmwang83@sina.cn

Abstract:

Static-gain and timing-skew mismatches among channels of TIADC significantly limit the Signal-to-Noise plus Distortion Ratio (SNDR) and the Spurious Free Dynamic Range (SFDR) of system. In this paper, an adaptive structure based on the Taylor series theory is proposed to compensate these mismatches. The novel structure is composed of differentiators and external reference channel. Controlled by the clock, sub-channels and reference channel sample simultaneously at some times. Comparing the output of reference channel with those of differentiators of sub-channels, the parameters of mismatches can be estimated, and then compensations can be carried out. The whole structure is implemented in the digital domain, and has the advantage of stability. Due to the special clock divider, all sub-channels share the same reference channel, which simplifies the system. Experimental results demonstrate that the SNDR and the SFDR of the output can be raised around 50dB, and the effective number of bits(ENOB) of the system can reaches about 12bits when the ADCs outputs are quantized to 14bits, which proves the validity of the proposed method.

Key words: TIADC, adaptive compensation, Taylor series, differentiator

CLC Number: 

  • TN911-5