The finite conical antenna

This paper describes the results of a theoretical and experimental study of the finite conical antenna. The antenna consists of a perfectly-conducting cone of finite length excited at its tip by a linear element. The radiation patterns and radiation resistance have been calculated by talking the current distribution on the linear element to be sinusoidal and approximating the current distribution on the finite cone with that of an infinite cone. Calculated and measured radiation patterns are found to be in good agreement. The dependence of beamwidth, beam tilt, and side-lobe level on the antenna dimensions is discussed. A simple interpretation of the patterns in terms of the superposition of a wave radiated directly from the linear element (in the presence of the infinite cone) and a wave diffracted from the edge of the cone is pointed out. Measured values of the input VSWR (voltage standing-wave ratio) are presented and discussed.