Some Practical Considerations for Reducing the Surface Resistivity of X-Band Components

In a recent experimental study program involving X-band waveguide components, various factors affecting RF resistivity were investigated. Specific results of this investigation included: l) the successful reduction of the RF resistivity of conventional beryllium copper castings by electroplating with higher conductivity metals, 2) decreasing RF resistivity by lowering surface roughness, 3) the attainment of microwave components cast from a higher conductivity casting alloy than beryllium coper, k) lowering of the RF resistivity by minimizing the effects of surface oxides and sub-surface contaminants, 5) "the use of OFHC and electroformed copper components to achieve low RF resistivity, and 6) an evaluation and comparison of dielectric and metallic protective coatings which inhibit the deterioration of waveguide surfaces. Accepted for the Air Force Franklin C. Hudson Chief, Lincoln Laboratory Office