Realization of a Lossy Material with a Prescribed Transparency Window in the Bulk

摘要

The research in this project addresses the issue of antenna proliferation. Whenever a multiplicity of antenna functions such as communications, intelligence, direction finding, and electronic warfare, must operate on a single platform, the need to isolate the antennas and their signals from each other becomes a performance-limiting problem. The only solution available today is to employ frequency-selective surfaces and solids (so-called Photonic Band Gap materials). These are carefully structured periodic arrangements of conducting or dielectric elements that create stopbands in their transmission functions at specific frequencies and angles. However, by definition these require complex manufacturing approaches with exacting tolerances, and they suffer from out-of-band grating lobes. The ideal solution to this packaging problem would be the existence of a bulk material that is only transparent at a prescribed frequency. Such a material would allow antennas operating at different bands to share 'real estate' with a minimum of mutual coupling. It would also allow the construction of frequency selective radomes with no out-of-band grating lobes. The proof that such a material can be constructed, with a tuned electromagnetic window obtained in the bulk through chemical means, is the subject of this research.