Behavioral modeling of analog circuits by wavelet collocation method

In this paper, we develop a wavelet collocation method with nonlinear companding for behavioral modeling of analog circuits. To construct the behavioral models, the circuit is first partitioned into building blocks and the input-output function of each block is then approximated by wavelets. As the blocks are mathematically represented by sets of simple wavelet basis functions, the computation cost for the behavioral simulation is significantly reduced. The proposed method presents several merits compared with those conventional techniques. First, the algorithm for expanding input-output functions by wavelets is a general-purpose approach, which can be applied in automatically modeling of different analog circuit blocks with different structures. Second, both the small signal effect and the large signal effect are modeled in a unified formulation, which eases the process of modeling and simulation. Third, a nonlinear companding method is developed to control the modeling error distribution, To demonstrate the promising features of the proposed method, a 4th order switched-current filter is employed to build the behavioral model.