077-99motl-abvdeterminant equation to design the resonator, it is only required to determine the phase of the reection coefcient of the resonating mode at a step discontinuity between an innitely long rod or ring and an innitely long cutoff wa¨ eguide. The technique is ¨ alidated by comparison to an analytical solution, as well as pre¨ iously published results from the literature. 1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 23: 203 205, 1999. Key words: dielectric resonators; ring resonators; circular wa¨ eguides I. INTRODUCTION Figure 5 Normalized main beam gain as a function of parasitic element spacing d sive option. The analysis presented here is for a horizontally polarized feed, suitable for terrestrial communications operating in most common fading conditions. The limitation of th……