A study of cylindrical resonant structures constructed from frequency-selective surfaces

An experimental parametric study of frequency selective guides, cylindrical structures constructed from square loop frequency selective surfaces, is p resented. Square loop resonators on a thin dielectric substrate are used fo r the frequency selective surface. The guides are intended for use in appli cations where lightweight, low cost and narrow band radiating systems are r equired. Comments on the manufacture of the guides are made. Propagating an d radiating regions of the structures are described. The effects of the thi ckness of the supporting substrate thickness are clearly displayed (shiftin g the resonant frequency), as is the dependence of the propagation loss at resonance on the number of resonators on the circumference of the guide. Th e thickness of the supporting substrate shows a smaller effect on loss. Fre quency scanning in the radiation region is also clearly established. Comple x propagation constants are obtained from the experimental results, using t hree methods. The 'short circuit radiation pattern' method gives results th at correlate best with simulated results. The guides show guidance over a f requency band determined by the frequency selective surface resonance. They also demonstrate a frequency scanning radiation broadside to the guidance direction.