A cupcake shaped CPW-fed printed antenna for UWB applications

A coplanar waveguide (CPW) - fed compact cupcake shaped printed antenna is proposed for UWB applications. Cupcake structure is formed by capping an ellipse (eccentricity = 0.95) over a semicircle (radius = 12mm). The bandwidth is enhanced by loading an ellipse over the semicircular patch and using CPW ground plane. The antenna parameters are simulated and optimized using Ansoft HFSS electromagnetic simulator. The proposed design fabricated by LPKF (S103) prototyping machine on 27 mm× 28 mm FR4 substrate ε_r = 4.4, thickness = 1.5 mm) exhibits a large impedance bandwidth (-10dB) from 2.8 GHz to 12.5 GHz. The developed antenna feature ultra-wideband (UWB) behavior with almost omnidirectional and stable radiation patterns over the entire bandwidth with an average peak gain of 4.5dBi. The simulation and experimental results are found to be in good agreement.