Fabrication and characterization of anisotropic dielectrics for low-loss microwave applications
- 183 Downloads
New magneto-photonic assembly designs for high-gain antennas require dielectrics with a significant anisotropy and low loss at GHz frequencies. This paper describes an approach to fabricate such dielectrics from ceramic laminates. These laminates consist of two ceramics with largely different permittivities and low dielectric losses. Alternating layers of commercially available α-Al2O3 and Nd-doped BaTiO3 were laminated using organic adhesives. Equivalent permittivity tensors and loss tangents were characterized using a resonant cavity-based approach, which was coupled with a finite-element method full-wave solver. Measured permittivity values were in good agreement with mean field predictions; a minimum loss tangent 1.1 × 10−3 was obtained when using one-component epoxy (Loctite®-3982) adhesive. Application of two-component epoxy (M-bond 610) adhesive results in a slightly higher loss but better mechanical properties and machinability. These laminates were used to demonstrate high gain in a prototype antenna with 6 misaligned anisotropic dielectric layers.
KeywordsRutile Anisotropic Dielectric Vitreous Silica Organic Adhesive Crystal Rutile
This work was supported by the U.S. Air Force Office of Scientific Research under the Grant FA9550-04-1-0359.
- 9.Kajfez D, Guillon P (1986) In: Dielectric resonators. Artech House, Inc., Dedham, p 53Google Scholar