Abstract: An ultra-wideband beamformer is provided by using conventional phase shifting techniques to impress data and antenna scan information onto a narrow band signal. A non-linear element then converts the narrow sine wave into ultra-wideband pulses. Phase shift key modulation impresses data information onto the sine wave in the form of a phase shift. The data-bearing sine wave is split into multiple transmission lines where each provides an additional antenna scanning phase shift. The non-linear element converts each phase of the sine wave into short pulses which are sent to radiating elements for transmission. In the far-field of the beam, the scan delays between the radiating elements are canceled out, such that the fields from each radiating element are summed and the pulse position modulated data recovered.

Abstract: A method for processing positioning signals in a ranging receiver in a geometric mode is provided. The method includes receiving timing information from a first set of satellites in a satellite constellation at the ranging receiver. The satellite constellation includes a plurality of satellites. A time of day is determined based on the received timing information. Approximate location data for the ranging receiver is determined. A frequency bias for the ranging receiver is determined. Ephemeris data is received from a second set of satellites in the satellite constellation. Superframe data for the satellite constellation is received from a third set of satellites in the satellite constellation at the ranging receiver. A pseudorange estimate is determined in the ranging receiver based on the time of day, the approximate location data, the frequency bias, the ephemeris data, and the superframe data.

Abstract: A system (20) and method (30) for estimating the location of a terrestrial-based user terminal (23) is provided. The user terminal (23) is capable of measuring the relative signal strengths of a plurality of spot beams pilot signal emitted from a geostationary satellite (22). The user terminal (23) then estimates its position based on the measured relative signal strengths. Using this approach, the user terminal (23) can quickly determine its location without prior knowledge of its position or delay time.

Abstract: An extensible short-range tracking system is disclosed. The tracking system disclosed is a multi-level tracking system. At the first level is an RF tag, which is a transmit-only unit that transmits information including minimally an identification number. The transmission from the RF tags are sporadic with timing depending upon the application at implementation. Generally, the transmission timing comprises a transmission, which is repeated periodically at random times. Transmissions from the RF tags are received in a series of relays. The relays may calculate the position of the tags by knowing the position of the relays and the time difference of arrival of the signals from the RF tags by several relays or may pass the information needed to calculate position to a base station. Alternately, the RF tags may generate position information and transmit that information along with the RF tag identifier to the relays.

Abstract: A system and method for beamforming signals received in sparse, irregular sensor arrays has a network of sensors organized into sensor clusters, a signal processing node for each sensor cluster for beamforming the signals received by the sensors in each sensor cluster and an aggregation node for combining the beamformed responses from each sensor cluster to form a composite response characterized by minimized side lobes and grating lobes.

Abstract: An adaptive antenna receiving apparatus includes (a) a plurality of antennas, (b) a plurality of adaptive receivers each of which receives signals received in the antennas, in an adaptive antenna pattern in an order in which the signals arrived at the antennas, (c) a plurality of initial receipt weight calculators each of which calculates an initial antenna pattern for each of the signals, and outputs the thus calculated initial antenna pattern to each of the adaptive receivers, (d) an adder which adds output signals transmitted from each of the adaptive receivers, to one another, and (e) a judge which symbol-judges an output signal transmitted from the adder, and transmits an output signal to each of the adaptive receivers.

Abstract: In an adaptive antenna device having directivity pattern generators operable in accordance with different algorithms, respectively, in a baseband modem, beam steering processing, null steering processing, and estimating processing of an arrival direction are executed in parallel to one another. Parameters resulting from the beam and the null steering processing are controlled by processing results of the estimating processing and are weighted and combined to individually generate directivity patterns based on the different algorithms.

Abstract: A radar tracking antenna system including: a parabolic-cylinder reflector; and, a subset of Flanking Beam Array Steered Technique (FAST) line feeds coupled to the reflector as a feed assembly.

Abstract: A method for beamforming signals for an array of receiving or transmitting elements includes the steps of selecting a beam elevation and azimuth and grouping elements of an antenna array into element ensembles that are substantially aligned with a wavefront projection on the antenna array corresponding to the selected beam elevation and azimuth.

Abstract: A pointing system and method for directing a first satellite system instrument to a first target is disclosed. The method comprises the steps of computing the orientation of a first satellite system instrument; computing a position of the satellite using measured orbital data; computing a target line of sight (LOS) vector direction from the satellite to the target using the computed orientation and the computed satellite position, and directing the first instrument to the first target according to the computed target LOS vector. The apparatus comprises at least one attitude sensor for the first instrument and a communicatively coupled satellite navigation system. The satellite navigation system determines the satellite position using measured satellite orbital data. The satellite navigation system computes the orientation of the first instrument using the attitude measurements, and computes the satellite position using measured satellite orbital data.

Abstract: The antenna system comprises a reflector which can be motionless, a source device and a device for treating the signals received by the source device. The system comprises means for automatically tracking the satellite that deviates from its initial position to an inclined orbital path.

Abstract: A first pair of antennas are mounted on a satellite spaced along a first axis and a second pair of antennas are spaced along a second axis for receiving signals from another satellite in orbit with the satellite, the first and second axes being orthogonal to a yaw axis that points toward the centroid of the celestial body about which the satellite orbits. Each pair of antennas are used to derive phase angle and signal strength differences, and these differences are used for deducing a yaw orientation of the satellite about the yaw axis.

Abstract: A system for directing an antenna for transmission over a two-way satellite network is disclosed. A transceiver is coupled to the antenna; the transceiver transmits and receives signals over the two-way satellite network. A user terminal is coupled to the transceiver and executes an antenna pointing program. The program instructs a user to initially point the antenna to a beacon satellite using predefined pointing values based upon the location of the antenna. The program receives new antenna pointing parameters that are downloaded from a hub over a temporary channel that is established via the beacon satellite. The program displays the new antenna pointing parameters and instructs the user to selectively re-point the antenna based upon the downloaded new antenna pointing parameters.

Abstract: The satellite navigational system integrated with the tilt measurement system capable of precise measurement of the actual coordinates of the mobile unit that moves along a track with variable tilt is disclosed. Using the integrated satellite/tilt measurement system, a plurality of 3 dimensional lines separated by optimal swathing offset vector can be formed and followed in order to provide field guidance during a precision farming operation across variably inclined terrain.

Abstract: An air traffic control system in which an airborne GPS receiver on a trans-oceanic flight is provided pseudo range correction data and satellite integrity information from a group of terrestrial HF transmitters, transmitting on a common set of frequencies and using a time division multiplexing scheme.

Abstract: An adaptive receiver includes an adaptive array unit and an equalizer unit. In the adaptive array unit, receiving signals of an array antenna are demodulated, weighted by multiplying with a complex weight calculated by an adaptive arithmetic unit, and adaptively combined. In the equalizer unit, propagation path estimation values are calculated from the receiving signals by a propagation path estimating unit, weighted with the complex weight by a complex weight adjusting unit, and adaptively combined. The combined demodulation signal is divided by the combined propagation path estimation value. Thereby, not only the unwanted signal wave of low correlation but also the unwanted signal wave of high correlation can be controlled effectively using an adaptive array antenna.

Abstract: A phased array antenna may include a substrate and a plurality of controllable phased array antenna elements carried thereby, a central controller for generating a mode selection signal and beam control signals, and at least one multi-mode element controller connected to at least one of the controllable phased array antenna elements and the central controller. The at least one multi-mode element controller may be operable in a desired operating mode from among a plurality of operating modes based upon the mode selection signal from the central controller. Furthermore, the at least one multi-mode element controller may also generate output signals for the at least one controllable phased array antenna element based upon the beam control signals from the central controller.

Abstract: A phased-array antenna apparatus used in a microwave or milliwave band and having a high gain includes a multilayer structure. The multilayer structure is constituted by M radiating elements, M phase shifters, phase shifting control circuits, and a feeding unit. The phase shifters are respectively coupled to the radiating elements to shift the phase of a feeding signal supplied to each of the radiating elements in units of N (M and N are integers equal to or larger than two) bits. The phase shifting control circuits control phase shifting of the phase shifters. The feeding unit is arranged to be coupled to each of the radiating elements.

Abstract: In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit.

Abstract: Signals received by antenna elements are respectively converted to lower frequency signals by the frequency converters. The lower frequency signals are then converted to the digital signals by A/D converters and supplied to a digital signal processing unit. The digital signal processing unit weights the digitized signals on the amplitude and the phase for each signal for optimally controlling the directivity. The weighted signals from the digital signal processing unit are converted to the analog signals by D/A converters and added by an adder. The added signal is then converted by a frequency converter to an original frequency of the received signals by the antenna elements.