Neil G4DBNWhen I'm designing a Cassegrain antenna for mmWave radio, the main dish is a parabola, but the deep ones from Edmund Optics are very hard to illuminate because they have a focal length to diameter ratio of 0.25, which is WAAAAAY less than most dishes. Solution is to put a hyperboloidal subreflector with its rear focus coincident with the prime focus of the parabola, and the front focus of the hyp is where you put the feedhorn. I made the rear so it can take a very fine adjustment thread
GNU social JP is a social network, courtesy of GNU social JP管理人. It runs on GNU social, version 2.0.2-dev, available under the GNU Affero General Public License.
All GNU social JP content and data are available under the Creative Commons Attribution 3.0 license.