aperture blockage造句

• Aperture blockage is normally due to shadowing by feed, subreflector and / or support members.
• However the centrifugal force and vibration and acts to prevent aperture blockage and agglomerated particle formation.
• Aperture blockage and deviation of reflector surface ( from the designed " ideal " ) are two important cases.
• In contrast, if multiple feeds are used with a parabolic reflector, all must be within a small angle of the optical axis to avoid suffering offset systems, dish antennas suffer from the feed and its supporting structure partially obscuring the main element ( " aperture blockage " ); in common with other refracting systems, the Luneburg lens antenna avoids this problem.