Title :
A Quadrature Bandpass Continuous-Time Delta-Sigma Modulator for a Tri-Mode GSM-EDGE/UMTS/DVB-T Receiver
Author :
Ho, Chen-Yen ; Chan, Wei-Shan ; Lin, Yung-Yu ; Lin, Tsung-Hsien
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ., Taipei, Taiwan
Abstract :
A second-order multi-bit quadrature bandpass continuous-time delta-sigma modulator (QBP-CTDSM) employing a power-scaling technique (PST) and a quadrature mismatch scrambler (QMS) for a tri-mode GSM-EDGE/UMTS/DVB-T low-IF receiver is reported in this paper. This modulator employs operational amplifiers with PST to optimize power consumption among the tri-mode operation. In addition, the modulator incorporates the proposed QMS to mitigate the mismatch between the I/Q multi-bit DACs. Fabricated in a 0.18-μm CMOS process, the proposed QBP-CTDSM achieves 81/61.2/60.9 dB SNDR across 270- kHz/5-MHz/8-MHz bandwidth. The bandpass center frequency is programmable from 500 kHz to 12 MHz. Measured from a 1.8-V supply voltage, the modulator power consumptions are 4.9/8.9/12.1 mW for the GSM-EDGE/UMTS/DVB-T modes, respectively, which result in FOMs of 0.99/0.95/0.84 pJ/conversion. The measurement results also show that the QBP-CTDSM achieves image rejection ratios better than 55 dB for all modes.
Keywords :
3G mobile communication; CMOS integrated circuits; cellular radio; delta-sigma modulation; digital video broadcasting; telecommunication standards; CMOS process; DVB-T receiver; GSM-EDGE; I/Q multibit DAC; UMTS; bandwidth 270 kHz; bandwidth 5 MHz; bandwidth 8 MHz; continuous-time delta-sigma modulator; low-IF receiver; power 12.1 mW; power 4.9 mW; power 8.9 mW; power-scaling technique; quadrature mismatch scrambler; second-order multibit quadrature bandpass; size 0.18 mum; tri-mode operation; voltage 1.8 V; 3G mobile communication; Digital video broadcasting; Modulation; Receivers; Signal to noise ratio; Topology; Continuous-time delta-sigma modulator (CTDSM); image rejection ratio (IRR); power scaling technique (PST); quadrature bandpass (QBP); quadrature mismatch scrambler (QMS);
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.2011.2164026
