Title :
A bandpass sigma-delta modulator IC with digital branch-mismatch correction
Author :
Comino, Vittorio ; Lu, A.C.
Author_Institution :
Wireless Technol. Res., Lucent Technol., Holmdel, NJ, USA
Abstract :
A bandpass sigma delta modulator, integrated in a 0.35 μm CMOS technology, samples a 82 MHz signal with a 109 MHz clock. The resolution is 11 bits over a 200 kHz bandwidth. To reach higher sampling rates the integrated circuit sub-samples the signal and uses the conventional two-branch parallel structure. A novel digital correction technique reduces the mismatch between the parallel branches increasing the signal to image ratio by 10 to 15 dB. This technique can be extended to structures with higher levels of parallelism
Keywords :
CMOS integrated circuits; calibration; parallel processing; radio receivers; sigma-delta modulation; signal sampling; 0.35 micron; 109 MHz; 200 kHz; 82 MHz; A/D conversion; ADC; CMOS technology; bandpass sigma-delta modulator IC; digital branch-mismatch correction; digital correction technique; sampling rates; signal subsampling; two-branch parallel structure; wireless receiver; Bandwidth; CMOS technology; Clocks; Delta modulation; Delta-sigma modulation; Digital integrated circuits; Digital modulation; Image sampling; Integrated circuit technology; Signal resolution;
Conference_Titel :
Custom Integrated Circuits, 1999. Proceedings of the IEEE 1999
Conference_Location :
San Diego, CA
Print_ISBN :
0-7803-5443-5
DOI :
10.1109/CICC.1999.777258
