Rectangular Patch Antenna Bandwidth Enhancement Applying New Sleeve-Arm Feeding

Expanding the bandwidth of a rectangular patch antenna (RPA) has been a research focus for decades. This paper proposes a sleeve-arm shape structure to expand an RPA's fractional bandwidth from 9.3% to 50%. The sleeve-arm configuration transforms the RPA's impedance values to be closer to 50 Ohm, allowing easy matching in a wider bandwidth, comparing with the conventional RPA. Simulated results show the impedance transformation and the corresponding broadband matching from 3 GHz to 5 GHz. This architecture is simple and occupies little space. It can be used in broadband applications to enhance patch antenna's impedance bandwidth.