Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide worldwide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.

Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide world-wide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.

Abstract: A mobile communication terminal or telephone comprising a handheld main housing incorporating a digital keypad, a speaker and a microphone, and having a planar radiator antenna. The antenna is hingedly-attached to an extension arm element which, in turn, is hingedly-attached at the top of the main housing. During use, the antenna is pivoted above and away from the head of the user by a sufficient distance to significantly reduce or remove the exposure of the user to transmitted RF power of sufficient density to pose a health danger.

Abstract: A communications satellite payload provides for efficient communications between user devices, such as hand held cellular telephones, and terrestrial gateways that may be connected to world-wide public telephone and telegraph (PTTs) networks. The satellite payload simultaneously supports a plurality of independent antenna beams, for example 12 or 16 beams, on both the uplink and downlink for user devices employing full duplex communications. The satellite payload furthermore supports an identical number of full duplex channels between a terrestrial gateway and the satellite. The communications satellite payload is carried by one satellite of a plurality of such satellites in a low earth orbit (LEO) constellation to provide worldwide communications. Downlink beam forming occurs prior to final amplification of transmitted signals, thereby reducing losses within the beam forming equipment.

Abstract: An aperture coupled microwave antenna (10) for processing circularly polarized signals. The antenna (10) comprises a first planar dielectric layer (22) upon which a conductive radiating patch (12) is mounted. Attached to the radiating patch (12) are tuning means (20, 72) for converting linearly polarized signals into circularly polarized signals. The tuning means preferably takes the form of conductive tuning stubs (20). Abutting an opposite face (23) of the first dielectric layer (22) is a conductive ground plane (24) having two orthogonal elongated apertures (26, 28). The radiating patch (12) is electromagnetically coupled, through the two elongated apertures (26, 28), to two input/output ports (48, 56) by two conductive feeding circuits (38, 40). Each of the feeding circuits (38, 40) interacts with only one of the elongated apertures (26, 28, respectively). The two feeding circuits (38, 40) and the elongated apertures (26, 28) are designed to operate in isolation.

Abstract: A microstrip antenna including an orthogonal planar array (12) of patch radiators (10) with specially configured feed boards (16) provided for each column of array elements. Each such board includes a portion disposed parallel to the plane of the array and one or more portions bent or folded to extend in the direction of the array axis for a distance sufficient to accommodate necessary circuitry (36) and active devices (40). A metal supporting frame (18) serves both as a common ground for the assembly and as a heat sink for conducting some of the heat generated by the active devices mounted to the feed boards. An additional planar circuit board (22) is positioned beneath the supporting frame to accommodate the power combining circuit and to interconnect all of the elements. Connection between feed boards (16) and combiner board (22) is accomplished using via-connections or a coaxial cable network.

Abstract: A microwave-frequency microstrip antenna (10) simultaneously usable for both transmitting and receiving microwave-frequency signals that have dual orthogonally polarized components. The components may be either linearly or circularly polarized. A radiating patch (26) is mounted on a first dielectric (12). A ground plane (20) abuts the first dielectric (12) and has two elongated coupling apertures (32,31) at right angles to each other. A second dielectric (22) abuts the ground plane (20) and has embedded thereon two substantially identical conductive planar feed networks (52,51) that are disposed at right angles to each other. At least one additional optional dielectric layer (16,18) having a conductive patch (36,34) may be interposed between the first dielectric (12) and the ground plane (20) for purposes of broadening the bandwidth of the antenna (10). A meanderline polarizer (45) or a 3 dB 90.degree. hybrid coupler (40) may be used for converting from linear polarization to circular polarization.

Abstract: A wideband, aperture-coupled microstrip antenna comprising a multilayer structure and including a feed layer, a ground plane including an aperture therethrough, a plurality of tuning layers formed of dielectric material, at least one of the tuning layers including therein a tuning element in the form of an electrically-conductive material, herein called a tuning patch, and final radiating layer including a radiating patch. The multiple tuning layers serve to extend the operational bandwidth of the antenna as compared to other microstrip antennas. Aperture coupling allows realization of the antenna using integrated circuit fabication techniques without the shortcoming of direct physical connections between the feedline and the radiator, and thus providing simple, yet reliable coupling between the feedline and the antenna.

Abstract: A generally planar antenna for generating circularly polarized electromagnetic signals, particularly useful at microwave frequencies. Each antenna element comprises a single excitation aperture (7) cut in a planar conductive ground plane (9). Spaced apart from the ground plane (9) by means of a dielectric layer (11) and covering the excitation aperture (7) is a planar conductive radiating patch (5) having slightly different dimensions along each of two orthogonal axes. The radiating patch (5) may have the shape of a near square or an ellipse. Exciting the aperture (7) with linearly polarized electromagnetic energy causes the radiating patch (5) to generate a circularly polarized electromagnetic signal consisting of two orthogonal components that have substantially the same amplitude and are 90.degree. offset in phase from each other. Several antenna elements can be combined to form a large aperture array.