Abstract A wideband planar antenna. which is composed of a ground plate and a strip surrounding the plate. is proposed. Wideband impedance matching with fractional bandwidth over 130% is achieved by making the distance between the strip and the ground plate stepwise so that the distance becomes wider in the tip side. https://www.jmannino.com/quick-offer-Viqua-F4-50-Plus-Monitored-UV-System-Powered-by-UVMax-15-gpm-230-Volt-on-sale/