Note that in the case of a front-fed Cassegrain the feed horn and feeder ( usually waveguide ) need to be covered with an edge absorber in addition to the circumference of the main paraboloid.
32.
The antenna consists of a thin rectangular section of a parabolic antenna, as if one cut the sides away from a conventional parabolic antenna, leaving only the thin strip where the feed horn is mounted.
33.
:: : : The official name seems to be a " feed horn ", but I don't think that's in common use outside the industry . talk ) 22 : 07, 23 July 2012 ( UTC)
34.
The antenna reflector was the same as Diyarbakir s initial FPS-17 antenna, but the feed horn numbers and configurations changed several times ( it is a curiosity that none of the three FPS-17 sites were exactly alike ).
35.
A disadvantage of the Cassegrain is that the feed horn ( s ) must have a narrower beamwidth ( higher gain ) to focus its radiation on the smaller secondary reflector, instead of the wider primary reflector as in front-fed dishes.
36.
The 7.5 Megawatt ( maximum power ) transmitter ran in normal operation at 5 Megawatt output pulse ( nearly 20 microseconds in duration ) and was conveyed from the transmitter to the antenna feed horn via a 9-inch diameter rigid coaxial connector.
37.
The antenna feed is usually considered to be all the components between the beam-shaping part of the antenna and the receiver's first amplifier ( called the RF front end, the feed horn, orthomode transducer, polarizer, frequency diplexer, waveguide, waveguide switches, rotary joint, etc.
38.
Such a device may be part of a VSAT antenna feed or a terrestrial microwave radio feed; for example, OMTs are often used with a feed horn to isolate orthogonal polarizations of a signal and to transfer transmit and receive signals to different ports.
39.
II only in the detail of the scanner antenna; IIA replaced the original dipole antenna at the scanner's focal point with a feed horn that sent the signal back to the receiver in a waveguide, eliminating the lossy coaxial cable of the earlier model.
40.
The asymmetric reflector allows the telescope's focal point and feed horn to be located at the side of the dish, so that it and its retractable support boom do not obstruct the incoming radio waves, as occurs in conventional radio telescope designs with the feed located on the telescope's beam axis.
