THE EXPANSION WAVE CONCEPT - PART II - A NEW WAY TO MODEL MUTUAL COUPLING IN MICROSTRIP ARRAYS

A new expansion scheme is introduced to solve the integral equations d escribing the mutual coupling in microstrip arrays. The scheme is base d on the fact that at larger distances the Green's functions in the st ratified dielectric medium of the antenna structure can be approximate d using analytical expressions. This allows one to describe the waves propagating between the elements thus causing the mutual coupling with a small number of parameters, Since only these parameters have to be determined, the resulting number of unknowns is much smaller than with conventional rigorous techniques. The accuracy of the scheme is illus trated by a comparison of measured and calculated data for both a two- element and a linear eight-element microstrip array antenna.