The Design of Metallic Delay Dielectrics

A theory of metallic delay dielectrics, which is more accurate than existing ones and is based on an analogy with shunt-loaded transmission lines, has been developed for the simplest case, when the delay medium consists of an array of infinitely long conducting strips. Formulae have been obtained for the refractive index, impedance and cut-off wavelength of such a medium, and the more important results are presented graphically. A procedure for designing such dielectrics to have a desired refractive index is outlined, and some limitations in the use of metallic delay lenses are pointed out.