The analysis of a center-fed helical microstrip antenna mounted on a dielectric-coated circular cylinder using the reciprocity theorem

The propagation and radiation characteristics of the tape helix with a conducting core and dielectric substrate have been investigated previously. The analysis techniques developed earlier either assume that the helix is infinite in extent or is being end-fed. In this paper, we consider a center-fed helical microstrip antenna of finite length. The reciprocity approach, originally introduced by Werner, Martin, Mittra and Zmyslo (see IEEE Trans. Antennas Propagat., 1999), is applied here in order to conveniently derive expressions for the far-zone radiation patterns of this helical microstrip structure.