Abstract: A low cost and low profile antenna for commercial use, either in a fixed or mobile condition is disclosed. The antenna has a generally flat circular plate that rotates to seam the azimuth direction. A plurality of radiation elements are positioned on the surface of the circular plate. The received signals are multiplexed, digitally converted, digitally beamformed, and then transferred to a digital receiver.

Abstract: A method for communicating and a communications system apparatus are disclosed. The apparatus comprises a communications platform and a gateway communicatively coupleable with a terrestrially-based network. The communications platform is disposed in a stratospheric location and transponds information between at least one of a plurality of user terminals and the gateway in essentially a bent pipe fashion. The method comprises the steps of receiving a first signal from the user terminal having an antenna in a stratospherically-based communication platform that maintains an apparent position relative to the user terminal within a beamwidth of a user terminal antenna and transponding the first signal from the stratospherically based communications platform to a gateway ground station.

Abstract: A terrestrial communication system using satellite uplink and downlink frequencies is disclosed. A terrestrial cell site produces a signal at a satellite uplink frequency that is transmitted to a terrestrial user terminal. The terrestrial cell site receives a signal at a satellite downlink frequency that was transmitted by a terrestrial user terminal. The terrestrial cell site may include a signal nulling means in the direction of a satellite producing signals at the uplink and downlink frequencies.

Abstract: A novel method and apparatus is described for reducing the number of CDMA codes for a constellation of multiple trasponder platforms serving a number of subscribers in the same service area. A coherent processing technique synchronizes the phase of CDMA signals arriving at a subscriber from multiple trasponder platforms to increase the code capacity and thus the number of possible subscribers for most of the multiple transponder platform systems in current use.

Abstract: A signal processing circuit for satellite communications signal includes a first one dimensional digital beam forming circuit for forming a beam signal in a first direction and a second one dimensional digital beam forming circuit for forming a beam in a second direction. A direction filtering circuit is coupled between the first one dimensional digital beam forming circuit and the second one dimensional digital beam forming circuit. The filtering circuit determining a communications signal direction of the satellite communications signal and tunes the filter to reduce a filter bandwidth and a frequency range of said beam signal prior to processing through the second one dimensional digital beam forming circuit.

Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.

Abstract: A modular mobile terminal for a satellite system is disclosed in which the satellite system has a ground station and a network such as a telephone network coupled to the ground station. Each of the mobile terminals has a radome layer and a support layer having a plurality of circuit traces formed thereon. An element module is coupled between the support layer and the radome layer. Each element module comprises a housing and a radiating patch having a feed therethrough. A dielectric layer is coupled adjacent to the radiating patch. A ground plane is disposed adjacent to the dielectric layer on the opposite side of the dielectric layer as the radiating patch. A plurality of circuit chips is coupled to the ground plane. The support layer of the array has a plurality of circuit traces formed thereon. A plurality of interconnections between the circuit chips and the plurality of traces connect the traces and the circuit chips.

Abstract: A terrestrial communication system using satellite uplink and downlink frequencies is disclosed. A terrestrial cell site produces a signal at a satellite uplink frequency that is transmitted to a terrestrial user terminal. The terrestrial cell site receives a signal at a satellite downlink frequency that was transmitted by a terrestrial user terminal. The terrestrial cell site may include a signal nulling means in the direction of a satellite producing signals at the uplink and downlink frequencies.

Abstract: A signal processing circuit for satellite communications signal includes a first one dimensional digital beam forming circuit for forming a beam signal in a first direction and a second one dimensional digital beam forming circuit for forming a beam in a second direction. A direction filtering circuit is coupled between the first one dimensional digital beam forming circuit and the second one dimensional digital beam forming circuit. The filtering circuit determining a communications signal direction of the satellite communications signal and tunes the filter to reduce a filter bandwidth and a frequency range of said beam signal prior to processing through the second one dimensional digital beam forming circuit.

Abstract: Methods for operating a satellite constellation are disclosed that utilize spatial diversity and directional gain antennas at ground terminal locations to provide multiple data rate services on a single frequency channel. One method comprises receiving a signal at a first and second satellite in the satellite constellation from a first communications device. A communications channel at a first frequency from the first satellite is used to communicate with the first communications device. A signal from a second communications device is received only at the second satellite at the first frequency, and the second satellite is used to communicate with the second communications device at the first frequency without substantially interfering with the communications with the first communications device.

Abstract: A method and system for determining a position of an object utilizes two-way ranging and polystatic techniques. A first communication transceiver at a first known location provides a bidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the first communication transceiver in response to the first ranging signal. The first communication transceiver further provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object.

Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.

Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.

Abstract: A modular mobile terminal for a satellite system is disclosed in which the satellite system has a ground station and a network such as a telephone network coupled to the ground station. Each of the mobile terminals has a radome layer and a support layer having a plurality of circuit traces formed thereon. An element module is coupled between the support layer and the radome layer. Each element module comprises a housing and a radiating patch having a feed therethrough. A dielectric layer is coupled adjacent to the radiating patch. A ground plane is disposed adjacent to the dielectric layer on the opposite side of the dielectric layer as the radiating patch. A plurality of circuit chips is coupled to the ground plane. The support layer of the array has a plurality of circuit traces formed thereon. A plurality of interconnections between the circuit chips and the plurality of traces connect the traces and the circuit chips.

Abstract: A low cost and low profile antenna for commercial use, either in a fixed or mobile condition is disclosed. The antenna has a generally flat circular plate that rotates to seam the azimuth direction. A plurality of radiation elements are positioned on the surface of the circular plate. The received signals are multiplexed, digitally converted, digitally beamformed, and then transferred to a digital receiver.

Abstract: A method and system for determining a position of an object utilizes two-way ranging and polystatic techniques. A first communication transceiver at a first known location provides a bidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the first communication transceiver in response to the first ranging signal. The first communication transceiver further provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a fourth ranging signal from the object.

Abstract: A method and system for determining the position of an object, such as an aircraft, utilizes two-way ranging with a polystatic satellite configuration and ground radar. A ground transceiver at a first known location provides a bidirectional communication path between the ground transceiver and the object wherein the ground transceiver transmits a first ranging signal to the object and the object transmits a second ranging signal to the ground transceiver in response to the first ranging signal. A first communication transceiver at a second known location provides a first unidirectional communication path between the first communication transceiver and the object wherein the first communication transceiver performs one of transmitting a third ranging signal to the object and receiving a third ranging signal from the object in response to the first ranging signal.

Abstract: A novel mobile satellite communications technique for hand-held terminals includes a satellite system having a plurality of individual satellites all in communication with a ground telecommunications hub. A signal processed by the ground telecommunications hub is radiated through multiple paths to a plurality of the individual satellites in the satellite constellation simultaneously. The radiated signal is then re-radiated by the plurality of individual satellites to a mobile satellite terminal that receives the re-radiated signal from the plurality of individual satellites simultaneously such that the same frequency spectrum may be re-used by another mobile user.

Abstract: A novel mobile satellite communications technique for hand-held terminals includes a satellite system having a plurality of individual satellites all in communication with a ground telecommunications hub. A signal processed by the ground telecommunications hub is radiated through multiple paths to a plurality of the individual satellites in the satellite constellation simultaneously. The radiated signal is then re-radiated by the plurality of individual satellites to a mobile satellite terminal that receives the re-radiated signal from the plurality of individual satellites simultaneously such that the same frequency spectrum may be re-used by another mobile user.