Figure 99. Cassegrainian antenna.
2-30.
CASSEGRAINIAN ANTENNA WITH POLYROD FEED
The polyrod feed system can also be used in conjunction with the cassegrainian antenna to obtain a highly
efficient low-noise antenna system as shown in figure 101. The polyrod feed guides the electromagnetic energy
to the hyperboloid subreflector. The polyrod's dielectric material is tapered toward the waveguide horn so that the
dielectric material can provide a uniform illumination of the hyperboloid subreflector. By using the combined
polyrod feed and the cassegrainian antenna instead of the conventional cassegrainian feed and antenna system, the
overall antenna size can be reduced by approximately 40 percent.
344 L2
93
Previous Page
