I have a simple two-element array, and I want to be able to quickly calculate far fields for arbitrary excitations. I've used Feko to generate two solutions, one for a symmetric excitation [a b] = [1 1], where a and b are the port voltages, and for an anti-symmetric excitation [1 -1]. I used these rather than [1 0] and [0 1] since Feko complains when a port excitation is zero. The ports are both 50 Ohms. Since Maxwell's equations are linear, superposition applies. My excitations are linearly independent, so I can combine them appropriately to generate an arbitrary excitation. Furthermore, I should be able to combine the radiated far fields in the same way. For example, if I choose [a b] = [1 exp(j*pi/4], I should get the same result whether I use superposition or calculate the fields directly with Feko. What I find, however, is a discrepancy in the results, and not a tiny one. Am I missing something?
