Title :
Narrow band noise suppression scheme for improving signal to noise ratio
Author :
Nag, Anantha ; Rao, K. Radhakrishna
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol. Madras, Chennai, India
Abstract :
In mixed signal systems, a weak signal is buried in strong interferers. The signal to noise ratio is poor. To convert the signal to digital, the dynamic range of the analog to digital converter cannot be efficiently utilized. The interference has to be reduced before the conversion. A notch filter can remove this interference. To allow for the uncertainty of the interference frequency, process variations, and ageing of components, it has to be self-correcting. This paper presents a scheme that improves the signal to noise ratio. This system will form the front end of any mixed mode system where the signal is known to be buried in narrow-band noise. The self-tuned notch filter has two parts: a tunable notch filter (a transconductor implementation of the universal active filter) and a control circuit. This has been implemented in 0.35 μm CMOS technology.
Keywords :
CMOS integrated circuits; active filters; circuit tuning; integrated circuit design; interference suppression; mixed analogue-digital integrated circuits; notch filters; 0.35 micron; 800 kHz to 2 MHz; ADC dynamic range; CMOS; SNR improvement; control circuit; interference frequency uncertainty; interference reduction; mixed mode system; mixed signal systems; narrow band noise suppression scheme; notch filter; self-correcting filter; self-tuned notch filter; signal to noise ratio; transconductor implementation; tunable notch filter; universal active filter; Active filters; Aging; Analog-digital conversion; CMOS technology; Dynamic range; Frequency; Interference; Narrowband; Signal to noise ratio; Uncertainty;
Conference_Titel :
VLSI Design, 2003. Proceedings. 16th International Conference on
Print_ISBN :
0-7695-1868-0
DOI :
10.1109/ICVD.2003.1183110
