Abstract: A reflex feed system for a dual frequency antenna which may be, for example, one which transmits and receives both S and X-band signals, uses, in place of the dichroic plate normally employed for directing X-band radiation away from the X-band horn a flange about the opening of the X-band horn.

Abstract: A broadband antenna system of small dimensions and composed of at least one antenna having an associated design operating frequency, and a plurality of reflectors operatively associated with the antenna and disposed at respectively different distances therefrom, each reflector being spaced from the antenna and having a reflection characteristic to be optimally matched with the antenna for operation at a respective partial frequency band, each reflector being associated with a different partial band such that the total operating frequency range of the system is divided into a plurality of partial bands equal in number to the number of reflectors and covering the design operating frequency range and a further frequency range below the lower limit of the design range, whereby the antenna characteristics are improved, and in particular the operative bandwidth of the system is increased in the low frequency direction.

Abstract: An antenna apparatus comprising a primary radiator having an axially symmetric field pattern, and a main reflector and a subreflector coupled to the primary radiator through a beam wave-guide path. The antenna rotating axis is aligned with the axis of the primary radiator but a little deviated from the polar axis or the earth. At least one movable beam waveguide reflector or electromagnetic lens is provided in a radio wave path between the primary radiator and the subreflector. The antenna rotating axis is adapted to be rotatable only within a small angular range. The beam wave-guide reflector or electromagnetic lens is moved to thereby deflect the antenna beam.

Abstract: An antenna for "frequency-re-use" that is provided with more than two parabolic cylinder surfaces (as reflectors), having in pairs common line foci, which foci intersect or cross each other, and having in pairs common symmetry planes.

Abstract: A reflector antenna used for radar, etc, has a subreflector so as to give a relatively large aperture diameter for a primary radiator, and to decrease the effect of the outer atmosphere.A subreflector having a different curvature in a vertical plane than a curvature in a horizontal plane is provided whereby an antenna having a different beam width in the vertical plane to that in the horizontal plane is provided even though a primary radiator having a rotationally symmetrical beam is employed.

Abstract: Control of the directivity, reflectivity, transparency and tuning of R.F. antenna array is accomplished by building antenna with short dipole segments with a switch between each two segments. The elements are properly connected to exhibit these electrical characteristics by remotely controlling the closing and opening of selected switches. The means for controlling the switches is isolated from the R.F. working frequencies of the antenna.

Abstract: A compact offset Cassegrainian antenna having a paraboloidal main reflector and a convex subreflector brings microwave beams to a focus. A small flat reflector placed in one of the beams at the focus deflects it for interception by a concave reflector and horn. Another beam passing by the flat reflector is intercepted by a second concave reflector and horn. The flat reflector is smaller than a focally located horn, allowing more closely-spaced beams to be accommodated. The flat reflector may be replaced by a curved reflector, a prism, or a microwave lens. Another flat reflector is added for each additional beam. Polarized beams are accommodated by adding a polarization screen.

Abstract: An antenna system for single or plural beams providing continuously variable beamwidth selectively in one or both of two orthogonal senses, i.e., azimuth and elevation, for either communications or angle-tracking. The system includes two parabolic cylindrical reflectors, which are respectively a main reflector and a sub-reflector; the reflectors are positioned with the focal axes thereof orthogonally. A point or multibeam (e.g., monopulse) feed is mounted adjacent the main reflector on the focal axis of the sub-reflector in the Airy disc of the system. Beamwidth is controlled using telescoping sections on the main and sub-reflectors to control the size of the surface areas thereof. Simultaneous operation of the telescoping sections of the reflector and sub-reflector provides bidirectional zooming of the beam without distortion while individual operation of the sections of the reflectors permits unidirectional zooming.