AlN high temperature co-fired ceramics with enhanced frequency selective transmission from X to Ku bands at elevated temperature

Syncretism of the functional structure and high temperature (HT) resistant ceramic are investigated to realize frequency selective transmission of device under HT environment. Focused on the electromagnetic (EM) properties of materials, metal tungsten with high-melting-point and ceramic AlN with stable permittivity under 1000 degrees C are selected as the functional structure and substrate of the proposed HT transmitter, respectively. To make the desired transmission, meta-structure is utilized into the design of W structure, which is designed inside AlN ceramic for metal's conductivity protection. In terms of fabrication, the transmitter is manufactured by high temperature co-fired technique. Through stacking sheets, lamination, and co-fired, the metal structure is processed in the sealed interlayer to prevent oxidation. As demonstrations, single- and double- layer transmitters are designed to satisfy single and double passband from X to Ku bands, respectively. The success of proposed design manner profoundly increases the design freedom for HT EM manipulation, and we firmly believe that the proposed design-fabrication method has great application potential in future EM devices in extreme environments.