Compact ultra-wideband antenna based on broadband radiating ground slit fed by microstrip line

A microstrip-line (MSL)-fed ground slit antenna with symmetric ground is proposed. The proposed antenna achieves good return performance over the entire ultra-wideband (UWB) frequency range (3.1-10.6 GHz), which utilizes three different radiating modes; dipole, ground slit and Vivaldi. Employing a loop shaped resonant section, which effectively enhances the impedance bandwidth of the slit mode and realizes the crossover of operating band of each mode, and suppressing of the imbalanced ground current flowing into the external ground circuit enables a compact antenna with a circuit area of 12 mm times 30 mm.