Leaky surface waves on curved surfaces

Summary form only given. R.S. Elliott´s work on leaky surface waves and their significance and some controversies concerning his work are reviewed. Elliott was the first to given an extensive analytical treatment of azimuthal surface waves on cylinders. This work, published in 1955, involved calculation of Hankel functions of the complex order. The complex order represents the propagation constant in the azimuthal direction. Floquet´s theorem was applied to an azimuthal periodic corrugated structure. The surface wave propagates along the curved surface, and the power is not completely trapped on the surface but leaks out continuously. This leaky surface wave concept was successfully applied to produce end-fire antennas. By proper choice of the radius of curvature and length of the arc, the main beam can be positioned at end-fire and the nulls of the pattern can be filled in. In 1956 Elliott studied spherical surface waves. Once again, the curvature controlled the placement of the main beam and the fill-in.<>