Monopole-like radiation of a dipole on a patch-loaded ground slab: how does it function?

In this paper, the radiation mechanism of the short horizontal dipole was investigated. It was found that the current on the on the unbalanced coaxial feed leads to the vertical monopole-like radiation. As such, the unbalanced horizontal dipole more closely resembles the classic T antenna. Furthermore, it was found that the surface wave which was excited by the T antenna was very weak in the frequency range where the TM mode closely follows the light line. In this range, the patches on the PLGS are acting primarily as a tuning structure for the T antenna and are of little significance as far as surface wave is concerned.