A Directive Subminiature Antenna for High-Power Ultrawideband Pulse Radiation

This letter presents a compact directive antenna to radiate a high-power ultrawideband (UWB) pulse. The proposed antenna is composed of a modified biconical-based radiator (electric dipole), magnetic dipoles, a feedthrough insulator, and a coaxial cable. The electrical size of the antenna is $0.195{\lambda _L} \times 0.195{\lambda _L} \times 0.176{\lambda _L}$ ( ${\hbox {width}} \times {\hbox {height}} \times {\hbox {\length}}$ ), where ${\lambda _L}$ is the wavelength corresponding to the lowest frequency of the bandwidth. The fabricated antenna realizes a bandwidth of 0.207–2.60 GHz (12.56:1) and a far-voltage of 131.3674 kV with a front–back ratio of 22.72 dB. The antenna is designed to radiate a $\pm 75~\hbox {kV}$ amplitude bipolar pulse with a 0.83-ns pulse width through the frequency band from 0.207 to 2.33 GHz.