Design a monopole antenna with three-tier small semicircles for ultra-wideband operation

This paper presents a monopole antenna with three-tier small semicircles for ultra-wideband operation. The monopole antenna with three-tier small semicircles which can get wider bandwidth is done by etching process on the FR4 substrate with 1.6mm in thickness and 4.4 relative permittivity. The ground plane is a semicircle with larger slit which is good for impedance matching. The S11 frequency response, radiation patterns, power gain, group delay, received pulse response, and phase change are also investigated. The relevant research reports can prove that a monopole antenna with three-tier small semicircles are very suitable for applications in ultra-wideband short-range wireless devices and apply to medical image.