Sensitivity Analysis and Distortion Decomposition of Mildly Nonlinear Circuits

by Zhu, Guoji

Abstract (Summary)
Volterra Series (VS) is often used in the analysis of mildly nonlinear circuits. In this approach,

nonlinear circuit analysis is converted into the analysis of a series of linear circuits. The main

benefit of this approach is that linear circuit analysis is well established and direct frequency

domain analysis of a nonlinear circuit becomes possible.

Sensitivity analysis is useful in comparing the quality of two designs and the evaluation of

gradient, Jacobian or Hessian matrices, in analog Computer Aided Design. This thesis presents, for

the first time, the sensitivity analysis of mildly nonlinear circuits in the frequency domain as an

extension of the VS approach. To overcome efficiency limitation due to multiple mixing effects,

Nonlinear Transfer Matrix (NTM) is introduced. It is the first explicit analytical representation of

the complicated multiple mixing effects. The application of NTM in sensitivity analysis is capable

of two orders of magnitude speedup.

Per-element distortion decomposition determines the contribution towards the total distortion

from an individual nonlinearity. It is useful in design optimization, symbolic simplification and

nonlinear model reduction. In this thesis, a numerical distortion decomposition technique is

introduced which combines the insight of traditional symbolic analysis with the numerical

advantages of SPICE like simulators. The use of NTM leads to an efficient implementation. The

proposed method greatly extends the size of the circuit and the complexity of the transistor model

over what previous approaches could handle. For example, industry standard compact model, such

as BSIM3V3 [35] was used for the first time in distortion analysis. The decomposition can be

achieved at device, transistor and block level, all with device level accuracy.

The theories have been implemented in a computer program and validated on examples. The

proposed methods will leverage the performance of present VS based distortion analysis to the next


Bibliographical Information:


School:University of Waterloo

School Location:Canada - Ontario

Source Type:Master's Thesis

Keywords:rfic volterra series analog circuits distortion analysis sensitivity decomposition circuit cad lna op amp electrical and computer engineering


Date of Publication:01/01/2007

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