A New Perspective on E-shape and U-slot Patch Antennas: Current Reshaping, Patterns Correction, and Polarization Reversal

Slot loading technique is well known for wideband patch antenna design, and the most famous examples are the E-shape and U-slot patch antennas. In the past, reported works mainly concentrate on how to widen the bandwidth with slots, but paid little attention to the radiation aspect. In this paper, a new perspective is presented on the current reshaping, patterns correction, and polarization reversal. Detailed analysis shows that loading of slot interrupts the on-patch currents of TM20 mode and changes the direction of the radiative components. As a result, the radiation beam is transformed from end-fire to broadside, while the cross-polarization is upgraded into co-polarization.