Microstrip patch arrays with spherical dielectric overlays

Theoretical and experimental results are presented to show that the performance of microstrip arrays can be enhanced by overlaying dielectric spheres on top of a patch array. In particular, the lens behavior of the dielectric sphere is used by the antenna to achieve increased gain, lower sidelobes, and lower cross-polar radiation despite the proximity of the patch near fields. The loss due to the dielectric material is found to be low but a further investigation is currently underway. The new antenna configuration has many applications at both microwave and millimeter wavelengths where a small increase in depth is not a problem.