A horn antenna with a cylindrical and an expanded (horn-shaped) waveguide for radiating or receiving polarized electromagnetic waves. The waveguide wall is partially or wholly covered with one or more grids (12) of electrical conducting material with dielectric layers between them. One possible design consists of a tapering (e.g., conical) core (10) of compact dielectric, which allows for the possibility of shaping the terminal surface (13) to a lens which curves the course of radiation in the aperture to the desired radiation graph. Another possible design where the horn wall consists of dielectric covered with metal grids has an especially light construction. The wall surfaces are developed with anisotrope and reactive impedance so that it mainly functions in the same way as a corrugated horn and thus gives low cross-polarizations across a large frequency area. This could be constructed with little weight and could easily be mass-produced. This will be easier to produce than corrugated horn, especially in the millimeter-wave area.

Hybrid mode horn antennas

A backfire feed antenna has a parabolic reflector with a ring-focus at the reflector focal point comprising a dielectric waveguide having a stem portion and a cap portion with a pointed end and most of the stem portion inside a conducting tube along the axis of the parabolic reflector. The outer surface of the cap portion is concave outward and convex inward and covered with a conducting layer. A curve between a parabola and hyperbola defines the surface. The cap portion has a conical surface extending between an annular surface at the junction between the stem portion and the cap portion and an axially extending circumferential surface surrounding the conducting layer. The inside end of the dielectric waveguide is pointed.

Backfire antenna feeding

A rear feed assembly for a microwave aerial, comprising a dielectric support member having an energy reflecting surface positioned against one face thereof. Waveguide means is connected with the support, the center of the waveguide aperture being the phase center of the assembly and the said face of the support being located in the far field region with respect to that center. The support is so shaped that energy emitted from the waveguide means is reflected from the reflecting surface and emerges through a second face of the support with a spherical wavefront centered on the image phase center.

Rear feed assemblies for aerials

Antennenanordnung, insbesondere cassegrain-antennenanordnung

An antenna has a waveguide horn extending from a main reflector. A dielectric tube extends from the distal end of the waveguide horn to support a sub-reflector in the focal region of the main reflector. An insert is placed into the dielectric tube to seat against the distal end of the dielectric tube. A fastener secures the insert to the sub-reflector, thereby securing the sub-reflector to the distal end of the dielectric tube. The surface of the insert serves as a continuation of the sub-reflector. The dielectric tube can be equipped with an inwardly-extending collar about its distal end to engage the insert.

Dish antenna having a self-supporting sub-reflector assembly

An end-fire antenna having a thick-wall dielectric tube concentrically positioned about the principal axis of a cassegrain antenna and seated on the main reflector functions as a guiding structure for focusing the antenna radiation.

Homer Eugene Bartlett

Papers

Cassegrain antenna with dielectric guiding structure