surface most importantly the secondary electron emission coefficients of all materials in the nanocomposite are small and close to unity whereas the previously used insulating particles can produce significant and undesirable electron multiplication application_number US 58468004 A description in order to achieve a nearly ideal material for high power microwave devices applicant has provided a high conductivity composite with mechanically strengthening nanoscale dispersoid particles that have electrical conductivity essentially matched with that of the base matrix metal this invention can utilize any one of three types of dispersoids the first being highly conductive metal nanoparticles artificially alloyed so that the matrix contains no or little dissolved dispersoid metal the second being dispersoid nanoparticles made of high conductivity intermetallic compound and the third being dispersoids comprising carbide nitride boride or carbon nanoparticles in traditional precipitation hardened cu alloys employing high temperature metallurgical reactions the electrical conductivity of the matrix metal u03c1 cu u02dc 1 67 u03bc u03c9 cm is significantly reduced by the solute atoms that do not completely precipitate any alloying element remaining in solid solution in the cu matrix deteriorates the electrical conductivity often by an order of magnitude or more in order to overcome such undesirable loss of conductivity in the cu composites applicant forms an.