Abstract: In a satellite communication system using optical carriers the down link radiation beam pattern is limited to illuminating only the receiver sites for power economy. The transmitting laser's beam pattern is shaped in such a way that the intensity distribution at the earth surface is adapted to the geographical distribution of the receiving stations. A suitably prepared hologram or set of stacked holograms storing different beam patterns is interposed in the radiation path. The antenna characteristic may be varied by selecting a particular hologram. This is accomplished by changing the beam angle of incidence by remote control.
Type:
Grant
Filed:
August 28, 1978
Date of Patent:
July 29, 1980
Assignee:
International Business Machines Corporation