Guided Waves on a Planar Helix

Considered here is a planar structure comprising a pair of parallel arrays of periodically spaced conducting strips which conduct in different directions in the two arrays. The guiding properties of this planar structure are found to be similar, in one case, to those of circular tape helices. While in general, different dielectric media are assumed in the sandwiched and outer regions, the special cases studied are 1) the case in which air constitutes both the media, 2) the normal-helix case in which the inner medium is a solid dielectric and the outer medium is air, and 3) the "inverted-helix" case with the two media interchanged.