Compact ultra-wideband antenna with inverted U-shaped slot and parachute-like radiation patch

A simple and compact wide-slot antenna for ultra-wideband application is presented. The antenna consists of an inverted U-shaped slot on a printed circuit board ground plane and a parachute-like radiation patch which is fed by a 50-Ω microstrip line. The antenna is built on a standard low-cost FR4 substrate with a whole size of 22*30*1 mm³. The measured and simulated results agree well and it indicates that the antenna has a measured impedance bandwidth varying from 2.75 to 20 GHz for S₁₁ ≤ -10 dB. In addition, the antenna shows nearly omnidirectional radiation pattern and stable gain within its operating band.