Fused Silica Ceramics and Composites for Radome Applications

The processing methods, strengthening methods, water-proof coating procedures, and some ways to improve the transmission of microwaves have been reviewed in relation to fused silica ceramics and their composites for radome applications. Fused silica ceramics are characterized by a residual porosity (up to 18%), low dielectric constant (3.06-3.32), low loss tangent (0.00053-0.0065), excellent thermal properties, but low mechanical strength (37-65 MPa). To achieve higher mechanical strength and better transmission efficiency, new randome materials would be those engineered composites consisting, for instance, of a dense layer-porous core structure, a continuous fiber reinforcement, a multilayered structure, and/or frequency selective surface (FSS) layer (s)/metamaterials.