Study of Nonlinearly Loaded Microwave Circuits by an Innovative Multiresolution Time-Frequency Analysis

This paper is dedicated to the development of a fast and accurate method for the transient analysis of microwave circuits with frequency dependent parameters and nonlinear loads. A convolution operator has been developed expanding the report input and output quantities by wavelets on the interval to overcome the intrinsic difficulty of this kind of problems in which nonlinear elements are better described in the time domain while circuit components are mostly characterized in the frequency domain. Because of their generality and easiness of use, the scattering parameters are used. A wavelet balance approach is discussed to solve the nonlinear equations arising from the presence of nonlinear terminations. Computational aspects are discussed and the results of application of this technique are compared with those obtained by other methods showing the accuracy and the efficiency of the proposed technique.