Radiation from quarter-wavelength monopoles on finite cylindrical, conical, and rocket-shaped conducting bodies

A theoretical-numerical technique, based on Maue´s integral equation, is applied for the determination of radiation patterns of airborne antennas comprising one or more quarter-wavelength monopoles, straight or bent, on finite cylindrical, conical, and rocket-shaped conducting airframes. The induced surface currents on the conducting body are first determined whence the total radiation fields are obtained. In the cases of a single monopole on a conducting body, the surface currents and radiation patterns are studied in view of varying the geometrical parameters of the body as well as the position and relative orientation of the monopole. For the case of two diametrically opposite monopoles on a finite cylinder, the effect of varying the relative phasing is studied. A physical interpretation of the variation with various parameters of the surface currents and the radiation fields is endeavored wherever feasible, and important results are concluded. Experimental investigation of radiation from one of the theoretically treated models, namely that of a bent monopole on a finite frustum of a cone, showed excellent agreement with computed results. This establishes the validity of the theoretical-numerical technique as well as the computed radiation patterns for various cases.