Patent ID: 7493240

Claim:
A computer implemented method for simulating responses of an analog circuit using a mixed frequency time method, the circuit receiving a periodic sample signal and at least one information signal, the method comprising the steps of: (a) selecting a set of evenly spaced distinct time points; (b) defining a set of reference time points, wherein each of the reference time points is associated with one of the distinct time points; (c) establishing a first set of relationships between values at the distinct time points and values at the reference time points, wherein the first set of relationships are defined by a first equation v − Tc =Φ Tc ( v − 0 ); where v − 0 =vector of signals at distinct time points, v − Tc =vector of signals at reference time points, Φ Tc =multicycle transition function; (d) establishing a second set of relationships between the values at the distinct time points and the values at the reference time points, wherein the second set of relationships are by defined by a second equation v −n Tc =D Tc ( v −n 0 ); where v −n 0 =vector of signals at distinct time points, for boundary condition n, v −n Tc =vector of signals at reference time points, for boundary condition n, D Tc =delay matrix; (e) combining the first and the second sets of relationships to establish a system of equations in terms of the values at the distinct time points, wherein combining the first and the second sets of relationships comprises combining the first and second equations to produce a third equation ( D T c {circle around (x)} I n ) v 0 −Φ T c ( v 0 )=0, where {circle around (x)} is a Kronecker product and I N is an N by N identity matrix; and (f) finding responses of the circuit at the distinct time points by solving the established system of equations, as defined by the third equation.