Analysis of nonperiodic perturbations to infinite periodic printed arrays

The analysis presented is capable of treating perturbations to either the excitation or the geometry of an infinite periodic array. It is based upon the solution to the perfectly periodic array, and therefore is best suited to problems having relatively localized perturbations to perfect periodicity. It is numerically efficient, becoming more computer intensive as the extent of the nonperiodic perturbation increases. The analysis is derived in terms of printed dipole arrays, but it is possible to apply the same techniques to other types of antenna arrays and related problems involving periodic structures. A rough outline of the basic theory of the method is discussed, followed by an example of an infinite printed dipole array having a small number of shorted elements.