Analog adaptive nonlinear filtering and spectral analysis for low-power audio applications

Filters are one of the basic building blocks of analog circuits. For linear operation, the power consumption is proportional to the dynamic range for a given topology. I have explored techniques to lower the power consumption below this limit by extending operation beyond the linear range. First, I built a power-efficient linear gm-C filter that demonstrates that dynamic range can be shifted to higher linear ranges using capacitive attenuation. In a standard gm-C filter, the minimum noise is limited by the discrete charge on the electrons and holes stored on the capacitor. This noise can only be reduced by collecting more charge on a larger capacitor, consuming more power. The maximum signal is determined by the linear range of the transconductor. This work showed that both the noise and the maximum signal can be amplified by including a capacitive attenuator in the feedback path of filter. In order to increase the dynamic range, I explored the non-linear operation of the filters, including jump resonance. Unlike harmonic distortion and gain compression which slowly increase with the input amplitude, jump resonance is not present in a linear system, but develops in the presence of strong nonlinearity.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Salthouse, Christopher Donovan, 1978-

Advisor dc:contributor.advisor

• Rahul Sarpeshkar.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/38310
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/38310

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/38310