High Thermal Conductivity Vacuum-Compatible Microwave Absorbers

Period of Performance: 06/28/2000 - 06/27/2002


Phase 2 SBIR

Recipient Firm

Sienna Technologies, Inc.
19501 144th Avenue NE Array
Woodinville, WA 98072
Principal Investigator

Research Topics


This Small Business Innovation Research (SBIR) Phase I project will establish the feasibility of vacuum compatible, electrically lossy high thermal conductivity aluminum nitride ceramics. Aluminum nitride will be doped to increase microwave absorption without adversely affecting its thermal conductivity, dielectric strength, and vacuum compatibility. Aluminum nitride disks with the selected dopant will be produced via pressureless sintering. Density, thermal conductivity, complex permittivity of the produced disks will be measured to assess their vacuum worthiness and microwave absorption. The effects of the dopant concentration on the density, thermal conductivity, and microwave absorption will be investigated. BENEFITS: Almost every medium-to-high vacuum electron device would benefit from the new non-toxic, vacuum compatible, high thermal conductivity lossy dielectric. Potential applications span a wide range of disciplines where microwave power sources are utilized. The applications include Klystrons and gyrotrons to supply microwave energy to improve the performance of chemical processes, and materials processing; Klystrons for direct broadcast satellites; gyrotrons for magnetic fusion based on electron cyclotron heating; microwave communications; induction heating; devices preventing TV picture ghost images; and other wave absorbing applications.