Global to push GA events into
skip to main content

Title: Vacuum-barrier window for wide-bandwidth high-power microwave transmission

A vacuum output window comprises a planar dielectric material with identical systems of parallel ridges and valleys formed in opposite surfaces. The valleys in each surface neck together along parallel lines in the bulk of the dielectric. Liquid-coolant conduits are disposed linearly along such lines of necking and have water or even liquid nitrogen pumped through to remove heat. The dielectric material can be alumina, or its crystalline form, sapphire. The electric-field of a broadband incident megawatt millimeter-wave radio frequency energy is oriented perpendicular to the system of ridges and valleys. The ridges, about one wavelength tall and with a period of about one wavelength, focus the incident energy through in ribbons that squeeze between the liquid-coolant conduits without significant losses over very broad bands of the radio spectrum. In an alternative embodiment, the liquid-coolant conduits are encased in metal within the bulk of the dielectric.
 [1];  [2]
  1. (Fremont, CA)
  2. (Tracy, CA)
Issue Date:
OSTI Identifier:
Regents of University of California (Oakland, CA) LLNL
Patent Number(s):
US 5548257
Contract Number:
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Country of Publication:
United States
vacuum-barrier; window; wide-bandwidth; high-power; microwave; transmission; vacuum; output; comprises; planar; dielectric; material; identical; systems; parallel; ridges; valleys; formed; opposite; surfaces; surface; neck; lines; bulk; liquid-coolant; conduits; disposed; linearly; necking; water; liquid; nitrogen; pumped; remove; heat; alumina; crystalline; form; sapphire; electric-field; broadband; incident; megawatt; millimeter-wave; radio; frequency; energy; oriented; perpendicular; wavelength; tall; period; focus; ribbons; squeeze; significant; losses; broad; bands; spectrum; alternative; embodiment; encased; metal; opposite surfaces; high-power microwave; incident energy; remove heat; radio frequency; alternative embodiment; dielectric material; opposite surface; broad band; liquid nitrogen; power microwave; frequency energy; window comprises; oriented perpendicular; output window; parallel lines; millimeter-wave radio; crystalline form; significant loss; wave radio; site surface; /333/29/