A novel miniaturized UWB monopole with five‐section stepped‐impedance feed line

A structure and design procedure of a compact ultra‐wideband (UWB) monopole antenna is proposed. In order to achieve additional size reduction, a modified‐shape feed line and a five‐section rectangular slit below the feed line is incorporated into a reference antenna featuring a two‐section rectangular slit below the feed line and two radiator slots. The minimum‐size is obtained by adjustment of all geometry parameters of the structure using rigorous numerical optimization. An explicit constraint on antenna reflection characteristic is imposed in order to ensure sufficient matching in the entire UWB frequency range. The footprint area of the final design is only 167 mm 2 with antenna dimensions of 22.46 mm × 7.45 mm. Experimental validation confirms good electrical and field properties. Thorough benchmarking indicates that the proposed antenna is competitive to recently reported designs.