Radiation field of spiral antennas employing multimode slow wave techniques

The results of both analytical and experimental research in the area of multimode slow wave planar spiral design are reported. This research is directed toward the development of a compact flush-mounted multimode antenna for future space applications. The technique followed in this investigation was to first modify existing analytical models of planar spiral antennas to take into account the effects of the slow wave geometry on the radiated pattern. These models are then used to optimize the design of certain multimode slow wave planar spiral antennas. Experimental antennas corresponding to these optimized designs were constructed and their field patterns are compared to those predicted by the analytical models. The comparison of the results indicates very favorable agreement between the analytical predictions and experimental data.