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A study of circularly polarized planar arrays using a radial line feed

Yi-Wei Liu, University of Massachusetts Amherst


The objective of this study was to develop a theoretical analysis model and a design procedure to synthesize aperture coupled microstrip patch arrays using a radial line feed. As a first topic, a lossy radial transmission line model is developed to predict slot coupling. With the reciprocity technique and a moment method analysis, key design parameters for realizing a radial line slot array are modeled to formulate the slot coupling problem. By applying the sequential array technique for circular polarization to radial line slot array design, good performance is found for both axial ratio and return loss bandwidth. The aperture efficiency degradation of a sequential array having elliptically polarized elements is investigated by evaluating the gain versus element spacing and polarization ellipticity. A sample design for a 18 cm aperture diameter radial line slot array with 42% aperture efficiency validates these theoretical approaches. Next, an aperture coupled microstrip patch array with a radial line feed is analyzed by modifying the analysis model of the radial line slot array. By using linearly polarized aperture coupled patches as radiating elements, sampled designs of aperture coupled microstrip patch arrays using radial line feeds are used to demonstrate the feasibility of this new structure.

Subject Area

Electrical engineering

Recommended Citation

Liu, Yi-Wei, "A study of circularly polarized planar arrays using a radial line feed" (1997). Doctoral Dissertations Available from Proquest. AAI9721470.