Ceradyne is a tier one supplier of specialty ceramics and cathodes to OEMs of high power microwave tubes and laboratories using high power microwaves. These components include Aluminum Nitride and “Lossy” Ceramics.

Aluminum Nitride

Aluminum Nitride is used to replace beryllium oxide components in microwave tubes in areas where thermal management is of concern, such as in collectors. Aluminum Nitride is selected because it is an electrical insulator having a thermal conductivity equal to beryllium at an operating temperature of 100°C to 200°C.

Ceradyne offers a complete family of fully dense Aluminum Nitride materials with the following key characteristics:

• High thermal conductivity
• Electrical insulation
• Corrosion resistance
• Large shape capability

For example, Ceralloy® 137 Sintered Aluminum Nitride is a fully dense material that can be produced in a cost effective manner for a wide range of applications (Microwave, Semiconductor, Special Components). Likewise, Ceralloy 147® Hot Pressed Aluminum Nitride can be formulated into a variety of compositions having minimal densification aids. Finished components are machined in Ceradyne’s precision diamond grinding facility.

“Lossy” Ceramics
“Lossy” Ceramics selectively absorb microwave energy of unwanted frequencies enabling a tube to produce energy at the desired frequency. These composites have tailored dielectric and loss properties to match specific microwave tube applications. “Lossy” Ceramics include:

• MgO-SiC Composites
• Al2O3-SiC Composites
• AlN-SiC Composites
• AlN Composites

The family of MgO-SiC materials is designed to absorb microwave energy in a very specific frequency range. Al2O3 composites and AlN based composites are broadband absorbers and are specifically designed to match the characteristics of the tube. These materials are used in various microwave tube applications including:

• Absorbers
• Load Pellets
• Terminations
• Severs

Visit our Microwave Components page to learn more.