The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarised systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.

Antenna feed and a reflector antenna system and a low noise (lnb) receiver, both with such an antenna feed

A chassis-excited antenna apparatus, and methods of tuning and utilizing the same. In one embodiment, a distributed loop antenna configuration is used within a handheld mobile device (e.g., cellular telephone). The antenna comprises two radiating elements: one configured to operate in a high-frequency band, and the other in a low-frequency band. The two antenna elements are disposed on different side surfaces of the metal chassis of the portable device; e.g., on the opposing sides of the device enclosure. Each antenna component comprises a radiator and an insulating cover. The radiator is coupled to a device feed via a feed conductor and a ground point. A portion of the feed conductor is disposed with the radiator to facilitate forming of the coupled loop resonator structure.

Chassis-excited antenna apparatus and methods

An adjustable multi-band planar antenna especially applicable in mobile terminals. In one embodiment, the feed of the antenna is connected by a multiple-way switch to at least two alternative points of the radiator element. When the feed point is changed, the resonance frequencies and thus the operating bands of the antenna change. In addition to varying the basic dimensions of the antenna, the distance between one feed point to another and a possible short-circuit point in the radiator, the value of the series capacitance produced by a reactive circuit that is formed between the feed point and switch, and the distance between the ground plane and the radiator, are parameters that may affect the antenna design.

Adjustable multi-band antenna and methods

A multi-band reflector antenna has a main reflector (12) defining a prime focus (11) and a frequency selective surface sub-reflector (50) defining an image focus (40). One or more transmitter or receiver feeds (32, 48) are provided at each of the prime focus and image focus. In one application as a ground satellite terminal, the antenna supports ka-band two-way broadband Internet access bundled with multi-satellite Ku-band direct broadcast television service.

Multi-band antenna for bundled broadband satellite internet access and DBS television service

An antenna component (and antenna) with a dielectric substrate and a plurality of radiating antenna elements on the surface of the substrate. In one embodiment, the plurality comprises two (2) elements, each of them covering one of the opposite heads and part of the upper surface of the device. The upper surface between the elements comprises a slot. The lower edge of one of the antenna elements is galvanically coupled to the antenna feed conductor on a circuit board, and at another point to the ground plane, while the lower edge of the opposite antenna element, or the parasitic element, is galvanically coupled only to the ground plane. The parasitic element obtains its feed through the electromagnetic coupling over the slot, and both elements resonate at the operating frequency. Omni-directionality is also achieved. Losses associated with the substrate are low due to the simple field image in the substrate.

Antenna, component and methods

An antenna has one feed (28) for an S-band electromagnetic signal, and a second feed (30) constructed as an array of radiators to service two C-band signal channels. A subreflector (26) having a microwave frequency selective surface (FSS) is placed in front of a main reflector (24). The C-band feed is constructed of an array of square aperture horns joined by separate transmit and receive barline beam-forming networks, and a meanderline polarizer to produce circularly polarized radiation patterns. Tapered ridges extend longitudinally along inner wall surfaces of each of the horns to provide increased bandwidth to the C-band feed. The frequency selective surface is constructed, typically, of a generally planar substrate of material transparent to electromagnetic radiation, and numerous metallic, generally annular, radiating elements, or resonators, arranged on the substrate in an array of repeating nested sets of the radiating elements. The lower frequency S-band feed is located behind and to the side of the subreflector for transmission of radiation via a folded optical path to the main reflector. The C-band feed is located in front of and to the side of the subreflector for transmission of radiation along a straight path through the FSS to the main reflector. The locating of the two feeds to the side of the subreflector permits the subreflector to be stowed by folding down upon the C-band feed, and the main reflector to be stowed by folding down upon both the S-band feed and the stowed subreflector.

Multiple band folding antenna

An antenna system having a front reflector and a rear reflector arranged in tandem, a front feed for illuminating the front reflector, and a rear feed for illuminating the rear reflector. Each of the reflectors has a generally dish-shaped configuration, and the feeds are located in positions offset from axes of the respective reflectors. The front reflector is reflective to a first radiation, while being substantially transparent to a second radiation except for a fraction of the power of the second radiation. The fractional part of the second radiation is reflected from the first reflector as an interfering beam, the interfering beam being scanned away from a coverage region of a beam of the first radiation by an offset between the feeds. The radiations may differ in polarization or in frequency. There may be a complete shading of the rear reflector by the front reflector from the radiation of the rear feed to produce uniform illumination of the rear reflector for greater accuracy in a formation of a beam from the rear reflector. Six degrees of freedom in positioning and orientation of the reflectors and their feeds provides maximum design flexibility for obtaining a compact antenna.

Antenna system with plural reflectors

PROBLEM TO BE SOLVED: To irradiate a grounding surface with two beams which do not interfere mutually by using two sets of feeds and reflectors arranged in the front and behind. SOLUTION: This antenna system 10 consists of two parabolic reflectors 12 and 14 and two feeds 16 and 18 which are supported and positioned by a supporting body 20. The feeds 16 and 18 are connected to transmitting and receiving equipment 22. Beams 28 and 30 of the reflectors 12 and 14 form beam footmarks 32 and 34 on the ground 26. Although radiation of the feed 18 is reflected by the reflector 14, the reflector 12 permeates the greater part of the radiation. An interference pattern due to a part of the reflection is so designed as to come outside the footmarks 32 and 34.

Sina Barkeshli

Papers

Multiple band folding antenna

Antenna system with plural reflectors

Antenna system provided with plural reflectors