On the Accuracy of the Shimbo Approach to Intermodulation and Crosstalk Calculations

To simplify the mathematics involved and to facilitate derivations of intermodulation and crosstalk formulas, the Shimbo approach uses a double Fourier transformation and represents the characteristics of a memoryless nonlinear device by a Bessel function series. Such an approach seems to be a very brave approximation as the approximated characteristics vary wildly with respect to the number of Bessel function terms
L
and with the amount of actual characteristic data used
(A_{F})
. However, it is shown here that the approach works well for the case involving two carriers with equal constant amplitudes, provided that one chooses
L
and A
F
properly.