A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads.
This invention was made with Government support under contract DE-AC05-84OR21400 awarded by the Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy to Lockheed Martin Energy Systems, Inc. The Government has certain rights in the invention.