Cassegrain antenna

About: Cassegrain antenna is a research topic. Over the lifetime, 3207 publications have been published within this topic receiving 28278 citations.

Efficiency measurement techniques for calibration of a prototype 34-meter-diameter beam-waveguide antenna at 8.45 and 32 GHz

Abstract: Efficiency measurements at 8.45 and 32 GHz (X- and Ka-bands) have been carried out on a new 34-m-diameter beam-waveguide antenna now in use at the NASA/JPL Goldstone Deep Space Communications Complex. The use of portable test packages enabled measurements at both the Cassegrain and the beam-waveguide focal points. Radio sources (quasars and Venus) were used as calibrators, and updated determinations of flux and source size correction were made during the period of the measurements. Gain and efficiency determinations as a function of elevation angle are presented, and the effects of the beam-waveguide system and antenna structure are clearly seen. At the beam-waveguide focus, an 8.45-GHz peak efficiency of 72.38% was measured; at 32 GHz, 44.89% was measured. >

Antenna with reflector

Abstract: An antenna which includes a monoconical antenna feed assembly, where the feed assembly has a base and an apex, a ground plane adjacent to the monoconical antenna feed assembly near the apex, and an antenna reflector coupled to the ground plane, where the antenna reflector at least partially surrounds the monoconical antenna feed assembly. The monoconical feed point is used to drive a reflector antenna. The broadband characteristics of the monoconical image vertical antenna (typical ground plane geometry) are used as the feed point for the reflector to give modest amount of gain while maintaining larger than previously developed bandwidths.

Focal field analyses for front-fed and offset reflector antenna

Abstract: In this paper, we present results of focal field analyses carried out for front-fed and offset parabolic antennas. Such analyses are needed and especially important for hybrid antenna configurations with arrays in the focal zone. The front-fed configuration relates to work carried out for radio telescope applications within the FARADAY project. The offset geometry relates to potential applications for instance for Earth observation or telecommunication satellites. The focal field analysis is necessary as an intermediate step, before focal field matching procedures are applied, to derive suitable excitations for a focal array. But also such an analysis gives insight from another point of view for antenna operations in the generic sense.

Dismountable and air-transportable antenna for two-way telecommunications with a satellite

Abstract: The antenna is preferably of the offset type and comprises plural thin and separable parabolic elements jointed into a parabolic reflector, and several substantially rectangular separable panels assembled into a prismatic lattice frame for supporting the reflector. The panels are substantially perpendicular to the lower base of the lattice and have curved upper edges formed in a duplicate mould according to the reflector and separable from the reflector elements. The antenna also comprises a telescopic elevation angle lifting mast and a circular aximuth positioner, both jointed to the frame and dismountable. The dismounted antenna is transportable in the form of standardized packages in the hold of long-distance airliner.

Dual reflector microwave directional antenna

Abstract: The catchment reflector (2), provided for an offset supplied Gregory or Cassegrain antenna is not a section of a rotation ellipsoid or rotation hyperboloid, but of a general ellipsoid (4) or hyperboloid having three half axes (a, b, c) of different sizes. The invention is intended to be used for directional radio and satellite radio antennas.