SAMPLED-DATA SIMULATION OF PERIODICALLY SWITCHED NONLINEAR CIRCUITS - Computer Methods for Analysis of Mixed-Mode Switching Circuits - page 157

because the frequency components in the circuits consist of the frequency
of the input and its harmonics only. For circuits with non-sinusoidal
inputs or multiple sinusoidal inputs, this does not hold.
Consider the input of the second-order Volterra circuit
as shown in Fig.7.5. To reduce Gibb effect, we introduce

a new function

where is a constant, and impose The value of

is therefore given by

Because is periodic, interpolating Fourier

series can be employed to derive without introducing a large error.

Once is available, can be obtained from the inverse of the

transform