Excitation of a conducting cylindrical surface of large radius of curvature

Approximate expressions are obtained for the magnetic field induced by slots on conducting circular cylinders of infinite length and of radius large compared to the signal wavelength. The approximations are derived from the formal solution of the cylinder problem and are valid for all distances from the slot. The expression for a short slot dipole, at any orientation, is expressed in terms of the field of the slot on a flat conducting sheet multiplied by a curvature term. The latter is a function of the "ray path" length and radius of curvature, making the results applicable to other convex surfaces. Corresponding expressions for half wavelength axial and transverse slots are also obtained and the results compared with experimental measurements.