Distortion Contribution Analysis with the Best Linear Approximation

TL;DR

This paper introduces a novel method for distortion contribution analysis in complex analog circuits using the Best Linear Approximation, simplifying interpretation and handling of non-linearities.

Contribution

It proposes using the Best Linear Approximation for DCA, enabling analysis of complex circuits with non-linear behavior more effectively than classical methods.

Findings

BLA-based DCA simplifies distortion source identification.

The method handles complex excitation signals.

It effectively manages strongly non-linear circuits.

Abstract

A Distortion Contribution Analysis (DCA) obtains the distortion at the output of an analog electronic circuit as a sum of distortion contributions of its sub-circuits. Similar to a noise analysis, a DCA helps a designer to pinpoint the actual source of the distortion. Classically, the DCA uses the Volterra theory to model the circuit and its sub-circuits. This DCA has been proven useful for small circuits or heavily simplified examples. In more complex circuits however, the amount of contributions increases quickly, making the interpretation of the results difficult. In this paper, the Best Linear Approximation (BLA) is used to perform the DCA instead. The BLA represents the behaviour of a sub-circuit as a linear circuit with the unmodelled distortion represented by a noise source. Combining the BLA with a classic noise analysis yields a DCA that is simple to understand, yet capable to handle complex excitation signals and complex strongly non-linear circuits.