Broadband pulse-optimised antenna

Abstract

The theoretical far-field pattern, gain, and aperture are derived for a V-shaped dipole carrying a nonuniform current wave. Particular attention is given to broadening in the far field of a sharp current pulse applied at the input. The optimum variation of characteristic TEM wave impedance is then derived with reflection coefficient and pulse broadening as constraints. Measurements on a practical design of 70 cm length show a bandwidth from 200 MHz to 1.6 GHz for an input voltage reflection coefficient less than 0.1 and a pulse broadening of 35ps. The directional diagram is±25° to half power.