Circuit Distortion Analysis Based on the Simplified Newton's Method

M M Gourary,S G Rusakov,S L Ulyanov,M M Zharov,B J Mulvaney

doi:10.1155/2011/540305

M M Gourary, S G Rusakov + Show 3 more

Open Access

https://doi.org/10.1155/2011/540305

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Abstract

A new computational technique for distortion analysis of nonlinear circuits is presented. The new technique is applicable to the same class of circuits, namely, weakly nonlinear and time-varying circuits, as the periodic Volterra series. However, unlike the Volterra series, it does not require the computation of the second and third derivatives of device models. The new method is computationally efficient compared with a complete multitone nonlinear steady-state analysis such as harmonic balance. Moreover, the new technique naturally allows computing and characterizing the contributions of individual circuit components to the overall circuit distortion. This paper presents the theory of the new technique, a discussion of the numerical aspects, and numerical results.

Highlights

RF circuits are generally designed to be linear with respect to the signal path
The desired signal may be weakly distorted due to nonlinearities of the circuit components. Analyzing this nonlinear distortion is an important problem in the design of RF circuits [1, 2]
We compare our new approach for the periodic distortion analysis based on

Summary

Introduction

RF circuits are generally designed to be linear with respect to the signal path. the desired signal may be weakly distorted due to nonlinearities of the circuit components. It is important to note that the proposed approach does not require computing high-order derivatives of device model nonlinearities, and there is no need to code the second and third derivatives for all the device models This approach provides basically the same order of accuracy as the Volterra series, due to properties of the simplified Newton’s method. A similar approach to distortion analysis has been proposed [20] which is based on linear-centric models and successive chord method This likewise avoids the computation of second and third derivatives of device models but differs from the presented technique in computation of third-order and higher-distortion components, essential for determining the IM3 metric.

Formulation of the Approach

Distortion Analysis in Frequency Domain

Computation of Individual Contributions

Numerical Results

Conclusion