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.