Use of a low dielectric loss silicon nitride material in radome applications

摘要

A composition having low dielectric constant and low dielectric loss tangent from room temperature to at least about 1100°C which comprises a silicon nitride based material containing an effective amount of a sintering aid selected from lanthanum oxide, yttrium oxide, lanthanum aluminate, yuttrium aluminate, aluminmum oxide and mixtures thereof and an effective amount of a low dielectric loss promotor selected from the group consisting of iron, chromium and mixtures thereof is a suitable radome material and electromagnetic window material.