The Electric and Magnetic Constants of Metallic Delay Media Containing Obstacles of Arbitrary Shape and Thickness

The dielectric constant and permeability of a metallic-obstacle medium are obtained in this paper by various static methods. The equivalent shunt capacitive susceptance and series inductive reactance of the individual obstacles are also determined. In the first part of the paper, a correspondence is established between an infinitely thin conducting obstacle and an aperture in an infinitely thin conducting wall. With the aid of this correspondence, delay medium formulas are given for several obstacle shapes. Formulas are then derived for the effect on the magnetic field of moderate obstacle thickness. Finally, it is shown how the electric and magnetic constants may be evaluated by electrolytic tank measurements in the case of obstacles having completely arbitrary shape and thickness. This has been done for a typical delay medium, and the effect of obstacle thickness on the index of refraction is shown.