Effect of element spacing and curvature on the radiation patterns of patch antenna arrays mounted on cylindrical multilayer structures

We have developed a computer program which calculates radiation patterns of an array of N/spl times/N patch antennas located above or inside a multilayer circular cylindrical structure by using the spectral domain approach. In the present paper, we use the program to study the effects of the curvature of the structure on the radiation pattern. The results show that the radiation pattern in the azimuthal direction is strongly dependent on the cylinder radius but much less so in the elevation direction. The results also show that the array exhibits high sidelobes which can be reduced by making the element spacing smaller than is necessary in the planar array.