Comparison of planar dipoles in UWB applications

The characteristics of four planar dipoles are studied and compared based on the design considerations of ultrawide-band (UWB) antennas. Their impedance matching, realized gain, and polarization over the UWB band are investigated. The current distributions on the dipoles are illustrated to interpret their different radiation characteristics. Furthermore, pulses radiated in different directions are presented for both single-band and multiband schemes in UWB applications.