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. A multi-element phased array of receiving antennas and a multi-element phased array of transmitting antennas is also disclosed, wherein each element of each phased array is utilized for each individual one of a plurality of received or transmitted beams.

Mobile communication satellite payload

A displaced feed antenna, operating at UHF, microwave, millimetre wave and tetrahertz frequencies, of mostly spaced conducting plate construction that incorporates electronically selectable feed points with associated antenna beam positions, which displaced feed antenna comprises: (i) a set of one or more beamforming configurations means (6) composed of layered, interlinking spaced conducting plates (1 ) and conducting boundaries that are separated by cavities containing dielectric material or free space; (ii) a set of one or more internal focusing means for each beamforming configuration to route radio frequency energy to or from the displaced feed points on receive and transmit respectively; (iii) a linear or curved array of displaced feed means for each beamforming configuration for coupling radio frequency energy into, or from, the cavity between the plates (2); (iv) a selection means (4) to allow definable overlapping regions of the focussing means to be illuminated for each beamforming configuration, by routing radio frequency energy via either selectively reflective elements or adjacent elements, or combinations of both, to create a displaced feed, controllable in extent and position, within the array of displayed feeds; and (v) a radio frequency transition means (3, 5) for each beamforming configuration between spaced conducting plates to free space, allowing either single polarisations or dual polarisation operation.

Displaced feed parallel plate antenna

A phased array antenna system having low power amplifiers reduces power loss through several tens meters high frequency cables. The antenna system for transmitting a signal in a base station, comprising: a phased array unit for selecting an input signal through one of a plurality of beam ports, for dividing the input signal into a plurality of signals and for outputting the plurality of signals through a plurality of array ports, each of the signal having a linear phase difference according to difference of propagation path; a switch for receiving the input signal from a base station, for selecting one of the plurality of beam ports of said phased array and for transmitting the input signal to the selected beam port, responsive to a control signal transmitted from the base station; a plurality of low power amplifiers for low power amplifying the plurality of signals inputted from the plurality of array ports of said phased array; and phased array antennas for radiating the plurality of signals from said plurality of low power amplifiers, thereby providing a spatial power summation into a direction of equiphase plane allowing effective radiated power sufficiently enough to cover a cell into a steered direction selected by said switch.

Phased array base station antenna system having distributed low power amplifiers

This invention relates to a satellite signalling system, such as a satellite paging system, having signal coverage over a very wide area. The satellite signalling system comprises a satellite (24) to which is coupled an antenna (22) for providing a signal beam having a variable beam area. The satellite can control the position of the antenna such that the signal beam can be directed in a predetermined sequence to a plurality of locations (28) on earth. The antenna (22) is arranged to vary the signal beam's area in dependence on the location to which the signal beam is directed. The signal beam comprises a data signal having a data rate which can be varied by the antenna in dependence on the beam area.

Satellite signalling system having a signal beam with a variable beam area

An antenna including a lens that has an array of radiating elements located on a focal arc, each radiating element corresponding to a different transmission beam direction; and a beam launcher having a plurality of phased arrays and a plurality of internal probes, each of the plurality of internal probes being electrically coupled to a corresponding one of the radiating elements, the phased arrays for space feeding a selected one or more of the radiating elements with signals so as to generate corresponding transmission beams from the lens.

Shared aperture antenna for independently steered, multiple simultaneous beams

A beamforming system for a linear phased array antenna system which can besed in a monopulse transceiver, comprising a pair of series connected parallel plate constrained unfocused lenses which provide a suitable amplitude taper for the linear array to yield a low sidelobe radiation pattern. Digital phase shifters are used for beam steering purposes and the unfocused lenses decorrelate the quantization errors caused by the use of such phase shifters.

Joseph P. Kobus

Papers

Dual space fed parallel plate lens antenna beamforming system