Study of Q factor and loop delay effects of a continuous-time Δ Σ AD modulator

Author

Lin, Haijun ; Motozawa, Atushi ; Ré, Pascal Lo ; Iizuka, Kunihiko ; Kobayashi, Haruo ; San, Hao

Author_Institution

Gunma Univ. of Japan, Kiryu, Japan

fYear

2009

fDate

20-23 Oct. 2009

Firstpage

230

Lastpage

233

Abstract

This paper describes the design and analysis of a continuous-time bandpass ΔΣ AD modulator for RF sampling. We determined the SNDR degradation due to finite Q value of the loop resonator, and due to excess loop delay (ELD). SNDR was improved by 20 dB by adding a digital filter which compensates for the effect of finite Q value, and SNDR was further improved by 20 dB by feedforward with parameters optimized to compensate for ELD. We have confirmed the effectiveness of the digital filter and feedforward proposals using Matlab and SPICE simulations.

Keywords

Q-factor; SPICE; analogue-digital conversion; delta-sigma modulation; digital filters; mathematics computing; resonators; AD modulator; Matlab; Q factor; SPICE simulations; bandpass modulator; continuous-time delta-sigma modulator; digital filter; loop delay; loop resonator; Band pass filters; Degradation; Delay effects; Digital filters; Digital modulation; Q factor; RF signals; Radio frequency; Sampling methods; Transfer functions; Continuous-time Δ Σ AD Modulator; ELD; Q value; RF sampling; Sub-sampling;

fLanguage

English

Publisher

ieee

Conference_Titel

ASIC, 2009. ASICON '09. IEEE 8th International Conference on

Conference_Location

Changsha, Hunan

Print_ISBN

978-1-4244-3868-6

Electronic_ISBN

978-1-4244-3870-9

Type

conf

DOI

10.1109/ASICON.2009.5351486

Filename

5351486