Analytic edge smoothing for planar UWB circular monopole antennas fed with coplanar waveguides

This paper presents a methodology to improve the performance of an UWB circular monopole antenna fed with a coplanar waveguide by coupling the waveguide slowly into the radiating element using a pre-defined curve that satisfies boundary conditions on the contour and its derivatives. The resulting antenna is modelled in Matlab and then transferred to CAD programs for simulation and manufacture using script languages. Simulation results carried out in HFSS and lab-test results recorded with a vector network analyser in an anechoic chamber are reported and compared to a reference design previously published and to an equivalent antenna without smoothing.