Broadside circularly-polarized radiation generated by surface wave diffraction

Conventionally, the surface wave radiation enabled by periodic structures which generate a leaky mode with the propagation constant at its -1 harmonic requires a large-size radiator and a complicated dispersion control in geometrical shapes. In this work, we exhibit a method of implementing surface wave radiation by predetermined diffractions. It applies dielectric truncation along the circumference as diffraction discontinuities without periodic structures involved. We demonstrate that the spatial distributions of the emitted radiations and the polarization of the electric field can be controlled through the manipulation in amplitude and phase of the surface wave diffraction.