Summary
International Symposium on Nonlinear Theory and its Applications
2005
Session Number:4-1-3
Session:
Number:4-1-3-4
Intermodulation Analysis of Nonlinear Circuits Using Two-Dimensional Fourier Transformation
A.Ushida, J.Kawata, Y.Yamagami, Y.Nishio,
pp.282-285
Publication Date:2005/10/18
Online ISSN:2188-5079
Summary:
Distortion analysis of nonlinear circuits is very important for designing analog integrated circuits and communication systems. In this paper, we propose an efficient frequency domain algorithm for analyzing the intermodulations of mixers and modulators driven by multiple inputs. Firstly, using ABMs(Analog Behavior Models) of Spice, we have developed a Fourier transformer executing the two-dimensional Fourier transformation. Then, the device modules for nonlinear elements such as diodes, bipolar transistors and MOSFETs are modeled by the Fourier transformer. Applying these modules, we can formulate the determining equations of the harmonic balance method in the form of equivalent circuits. Thus, they can be solved by the DC analysis of Spice, so that we can easily obtain the characteristics such as the frequency response curves and intermodulation phenomena. In our algorithm, we need not derive any troublesome circuit equation and the transformations into the determining equations, so that our simulators are user-friendly for solving these circuits.