Wideband High Gain Antenna Realized From Simple Unloaded Single Patch

A wideband antenna has been conceived and realized from a single metallic patch with air as the substrate. The patch has been strategically folded to achieve dual resonances resulting in $\text{S}_{11} \leq 10\,\text{dB}$ over a wide matching bandwidth. Basic design concept has been discussed and experimentally verified. As much as 26% bandwidth covering almost the full X-band with about 9.6 dBi peak gain has been experimentally demonstrated from a $20.3\,\text{mm} \times 13\,\text{mm}$ patch folded to realize $13\,\text{mm} \times 13\,\text{mm}$ footprint.