----------------------------------- HarapAlb 13 Sep 2008 18:28 ----------------------------------- din Certain modifications have already been suggested on to these antennas and particularly on Cassegrain antennas to reduce the aperture-blocking effect which increases with the size of the subsidiary reflector or subreflector. These suggestions include .... It is also possible to build a semi-transparent subreflector which reflects the beams issuing from the source with a certain polarization and allows beams to pass whose polarization has been turned by 90° at the main reflector... Incercati un test cu lumina polarizata.