Microstrip Patch with a Vertical Loading for Improved Radiation Properties

This study introduces a novel design approach to reduce the cross-polarized (XP) radiation from a microstrip patch over the orthogonal plane. A vertical loading is positioned at the center of the patch to attenuate the fields originating due to TM
02
mode. In contrast to earlier reported works, this loading is printed on a PTFE substrate to minimize the loading height. This breaks the fundamental notion of $\lambda$/4 loading height for XP suppression. A C-band rectangular patch is used for the study. The proposed method reduces the loading height by 77 %. It also suppresses the XP radiation over the orthogonal plane by 15 dB, maintaining the input impedance and co-polar radiation patterns undisturbed.