TWT reliability and maintainability

The relationship between reliability and derating in traveling wave tubes (TWTs) is often disregarded. It is ignored because of competitive business pressures and incomplete design capability evaluation. Adequate derating will produce significant reliability improvements as compared to units operated at their capability limits. In order to do this, however, each TWT's true capability limits must be determined. Maintainability, as used in this discussion, refers to the maintenance of the TWT's electrical and thermal environment. Since most TWTs are not field repairable, there is little that can be done to the device itself to assure its continued operation once it has been produced. Therefore, design consideration must be given to require (by the TWT) versus existing field environments.