A digitally calibrated CT quadrature bandpass ΣΔ ADC for Wimax/LTE

Author

Leonida, Angeliki ; Mutgan, Orhan Hazar ; Rusu, Ana

Author_Institution

ECS/ICT, R. Inst. of Technol. (KTH), Stockholm, Sweden

fYear

2009

fDate

9-10 July 2009

Firstpage

1

Lastpage

4

Abstract

This paper presents a digitally calibrated continuous time quadrature SigmaDelta ADC for WiMAX/LTE narrow bands. The proposed architecture employs a 5^th order 2-bit quadrature bandpass SigmaDelta modulator. Dithering and Adaptive Line Enhancement techniques are combined to compensate for mismatch errors in the I/Q paths. The proposed calibration technique introduces no complexity in the ADC design and can be used online. The simulation results show an improvement of 16.75 dB in SINAD and 34.42 dB in Image Rejection, when a plusmn30% variation in the loop active RC filter coefficients is introduced in the behavioral model.

Keywords

3G mobile communication; WiMax; active filters; analogue-digital conversion; I-Q paths; Wimax-LTE narrow bands; adaptive line enhancement techniques; digitally calibrated CT quadrature bandpass SigmaDelta ADC; dithering techniques; loop active RC filter coefficients; mismatch errors compensation; Analog circuits; Band pass filters; CMOS technology; Calibration; Computed tomography; Delta-sigma modulation; Low pass filters; Radio frequency; Signal to noise ratio; WiMAX;

fLanguage

English

Publisher

ieee

Conference_Titel

Signals, Circuits and Systems, 2009. ISSCS 2009. International Symposium on

Conference_Location

Iasi

Print_ISBN

978-1-4244-3785-6

Electronic_ISBN

978-1-4244-3786-3

Type

conf

DOI

10.1109/ISSCS.2009.5206193

Filename

5206193