The authors describe a low profile CPW and microstrip-fed half-circle planar monopole antenna with a dual rectangular slit, which has similar radiation pattern properties for ultra-wideband applications. In this case, the inserted dual slit on the monopole also leads to enhancing the wide band impedance. The inserted dual slit on the monopole and feeding structures (CPW-fed and microstrip-fed with a dual open-stub) also leads to reducing antenna size and enhancing wideband impedance matching characteristics. The antenna has a low profile of 24 mm x 30 mm x 1 mm. The measured bandwidth is from 2.92 to 11.7 GHz for a return loss less than -10 dB. The proposed antenna also has a peak gain of 4.5 dBi.