Theory of reflections from the rodded-type artificial dielectric

It is demonstrated that a composite material of a solid dielectric with embedded conductors can give a wave impedance equivalent to that of free space, and thus eliminate interface reflections. A particular material, the rodded dielectric, is analysed, and design procedures are given which are exemplified by numerical results. An experimental verification of the design theory when the electric-field vector is wholly parallel to the axes of the rods is described, and the results show good agreement with the theory. Finally, methods of manufacture, and the tolerances required, are discussed.