Efficient Luneberg Lens for Multi-frequency SATCOM Antenna

"A Luneberg lens is a sphere of low-loss dielectric material whose index of refraction varies along any radius in accord with Luneberg's equation. The lens is inherently wideband and is a candidate for multi-frequency aircraft SATCOM antennas. Thecontinuous index of refraction variation of an ideal lens is often approximated by a series of concentric spherical shells of constant refractive indices. Difficulty has been encountered in achieving maximum gain performance at high microwave frequencies,believed due to difficulties with current multi-shell fabrication technology. Also, current fabrication materials possess a relatively low melting point, limiting transmitting power due to RF heating. We have recently invented syntactic foam compositematerial and fabrication technology for Luneberg lenses capable of overcoming within shell non-homogeneity, interfacial gaps between shells and current transmit power limitations. Utilizing prediction software using spherical wave functions and boundaryvalue matching, lens design will be optimized for performance/cost. Syntactic composites especially suitable for high frequency and high power performance will be developed. Specific recommendations for the target 8 inch diameter hemisphere illuminated at44 GHz will be determined. We anticipate demonstrating new composite technologies enabling the manufacture of low dielectric, low loss materials coupled with design techniques that allow fabric