Abstract: This invention exploits the synchronization properties of coupled, nonlinear oscillators arrays to perform power combining, beam steering, and beam shaping. This architecture utilizes interactions between nonlinear active elements to generate beam patterns. A nonlinear array integrates the signal processing concurrently with the transduction of the signal. This architecture differs fundamentally from passive transducer arrays in three ways: 1) the unit cells are nonlinear, 2) the array purposely couples the unit cells together, and 3) the signal processing (beam steering and shaping) is done via dynamic interactions between unit cells. The architecture extends to both 1- and 2-dimensional arrays.

Abstract: A radio antenna of a radio base station is a directional antenna. The antenna searches for a peripheral radio base station by changing the directivity of the antenna. An operating channel and electric field intensity of the other base station are acquired by the searching and then stored as positional information. The operating channel of the base station, the directivity of the antenna, and a radio wave intensity communication area are set according to the acquired positional information. Further, the positional information is transmitted and received to and from the other base station to set the base station. When the base station was moved or when external noise occurred abruptly, channel change and change of a cell shape of the directional antenna are carried out. Consequently, interference between the base stations can be minimized and optimum setting of the channel and communicatable area can be realized.

Abstract: Disclosed is a phase calibration method for inserting a calibration signal (SC) into main signals (SM1 to SMn) of a plurality of branches in turn, estimating the phase characteristic of an analog circuit to which a respective one of the main signals is input and calibrating the phase of each main signal. The method includes steps of outputting a first combined signal obtained by combining output signals from the analog circuits (62a to 62n) in all branches, outputting a second combined signal obtained by combining the main signals in all branches, extracting the calibration signal by removing the second combined signal from the first combined signal in a calibration signal extracting unit (64), estimating the phase characteristics of the analog circuits, to which the main signals having the inserted calibration signal are input, based upon a change in phase of the calibration signal, and subjecting the main signals to phase adjustment having characteristics that are opposite the phase characteristics.

Abstract: Transmitting and receiving compensation coefficients of each antenna element relative to a calibration antenna element are obtained in the pre-calibration of a smart antenna. After the antenna array is installed, in transmitting calibration, amplitude and phase response of each transmitting link is computed according to the calibration signals received by the calibration link and, together with the transmitting compensation coefficient obtained in the pre-calibration, the compensation coefficient of each transmitting link is computed to compensate the downlink data of a base station. In receiving calibration, the amplitude and phase response of each receiving link is computed based on the signals received by the receiving links and, together with the receiving compensation coefficient obtained in pre-calibration, the compensation coefficient of each receiving link is computed to compensate the uplink data of the base station.

Abstract: A real-time calibration method for a smart antenna array. The method includes: before installation, a smart antenna array is pre-calibrated to obtain transmission-coefficient matrix between antenna units; after installation at site, the pre-calibrated transmission-coefficient matrix is loaded in a base station to which the smart antenna array connects; during running, every transmission link of the base station transmits a unit calibration signal in sequence in a time-slot, and all other links, except the transmitting link, are in a reception state to receive the unit calibration signal, and the received unit calibration signals are recorded; with the received unit calibration signals and pre-calibrated transmission-coefficient matrix, the smart antenna array is calibrated. The method does not need beacon antenna, coupled structure of the antenna array and a special calibration link.

Abstract: In a radio communication system, a beam is formed between subscriber stations and a base station which has an antenna device with several antenna elements. The antenna elements emit a downlink signal based on respective weighing with coefficients of a weighting vector. A plurality of weighting vectors are determined at the subscriber station in an initialization phase and transmitted to the base station. In a subsequent working phase, the subscriber station selects a dominant weighting vector from the weighting vectors and transmits a designation of the selected weighting vector to the base station.

Abstract: Disclosed are systems and methods which provide communication network antenna pattern configuration for optimized network operation. Preferably, a statistical smart antenna configuration is provided in which antenna patterns associated with various base stations of the communication network are configured to capitalize on the complex morphology and topology of the service area in providing optimized communications. Antenna patterns are preferably configured using merit based determinations, based upon link propagation conditions such as associated with the complex morphologies and topologies of the service area, to aggressively serve areas which are best served thereby while not serving areas which are best served by other network systems.

Abstract: A genetic processor is used to process a plurality of baseband signals in a communication system. Signals received at an antenna array are processed to form chromosomes based on signal-to-interference-and-noise ratios. The chromosomes are further processed to determine a fitness of the chromosomes, and a weight set corresponding to a determined best fitness level is used to selectively process each signal corresponding to each antennae of the array to increase the dynamic range of the receiver. In-phase, quadrature, amplitude and phase are signal characteristics that may be processed. In the transmit direction, the chromosomes are used to process the modulating signal supplied to each RF antenna, thus resulting in beamforming, the actual signal processing occurs digitally in the baseband spectrum. Chromosomes comprise a number of genes, or bits, based on the type of encoding scheme and the polarization, number and array grouping of antenna elements.

Abstract: A device and method for the calibration and equalization of reception chains of an antenna processing system comprises several RF chains, each associated with a radiating element, a set of sensors Ci formed out of the outputs of the preceding RF chains, a channel for the injection of a calibration signal, means to couple the calibration signal to the sensor signals and several reception-digitization chains. The device comprises at least one processor adapted to managing all the devices; a means used to adjust the value of the gain of an RF chain to a minimum value Gmin; a means for deflecting the sensors, adapted to minimizing their directivity toward the interference sources; a means adapted to adjusting the level of the injected calibration signal ST relative to the signal of the sensors, an RF chain having a gain adjusted to a minimum value Gmin.

Abstract: A method is provided for beam shaping in a radio communication system having subscriber stations and a base station, and an antenna device with a number of antenna elements that emit a downlink signal weighted with a coefficient of an actual weighting vector to a subscriber station, the actual weighting vector being updated via feedback information from the subscriber station. The subscriber station estimates the direction of a control vector in an M-dimensional vector space using measurements of the downlink signals, it detects a deviation of the estimated direction from the direction of a reference control vector and transmits information representative of the deviation to the base station. The base station then adapts the weighting vector using the representative information.

Abstract: An improved calibration device for an antenna array, or an improved antenna array, is of simple construction. If the total number of antenna elements which are provided for a column is N, where N is a natural number, only N/2 or less coupling devices and/or probes are provided, the number of couplers or probes which are provided are associated with only some of the antenna elements; and a combination network is also provided, via which the coupling devices and/or probes which are provided are connected.

Abstract: According to one embodiment, an antenna beam pattern is used to send a communication signal to a user. For example, the antenna beam pattern can be formed using adaptive antenna array technology on the forward link of a wireless communication system. A control signal from the user is used to determine a statistic. For example, the control signal can be a power control bit sent by the user on the return link. The statistic can be an average of the power control bit values over a specified time interval. The statistic is used to narrow the antenna beam pattern and direct it toward the user. For example, a dithering algorithm can be used to optimize the antenna beam pattern. After a call is completed, an optimized antenna beam pattern specific to each user can be stored for the next call to make the optimizing process faster and more efficient.

Abstract: The disclosed embodiments relate to a system and method for providing user specific beams in a fixed beam network, the fixed beam network comprising a plurality of fixed beams, each of the plurality of fixed beams being defined by a plurality of fixed beam correlation coefficients. The system may comprise a device that computes reception correlation data for a received signal, and a beamformer that is adapted to determine transmission weighting coefficients to be applied to a return signal based on the difference between the reception correlation data and the fixed beam weighting coefficients associated with at least one of the plurality of fixed beams.

Abstract: A phased array, phase-amplitude monopulse antenna arrangement for ground, shipboard or airborne radar systems. The phased array antenna is systematically warped and projects partially overlapping, separate beams from upper and lower regions of the array. A single set of phase-shifters is employed with a simplified feed structure to permit development of both azimuthal and elevation angle error signals in signal processing circuitry for target analysis.

Abstract: Methods and apparatus provide vibration-free steered-beam antennas using a module to accommodate segregated de and rf signals. A phase-shifter element is disposed within an interior of the module. A radiating element is provided, and an rf interface is adapted to couple energy between the phase-shifter element and the radiating element. The rf interface is disposed entirely within the interior of the module and is adapted to provide an rf interface with the module substantially only through the radiating element. A dc interface is adapted to couple energy between the phase-shifter element and an electrical connection element disposed exterior to the module.

Abstract: A communication method comprises dividing each of a plurality of optical carrier signals into a plurality of intermediate signals wherein each optical carrier signal carrying all of a plurality of wavelength division multiplexed initial data signals and each intermediate signal carrying all of the multiplexed initial data signals over a predetermined wavelength range, separating each intermediate signal into the respective data signals contained therein, and combining corresponding data signals separated from the intermediate signals into their respective initial data signals.

Abstract: A received signal vector (X(t)) from an array antenna (#1 to #4) is subjected to frequency offset correction by a frequency offset correction part (6) and thereafter subjected to adaptive array processing. An error signal (e(t)) is referred to on the basis of an output signal (y(t)) from the adaptive array and a reference signal (d(t)) held in a memory (30) in a reference signal section or a replica signal (d?(t)) output from a forced phase-locking processing part (20) in a section having no reference signal, so that a frequency offset quantity (??) is extracted therefrom by an offset extraction part (100).

Abstract: An apparatus (and corresponding methodology) for discovering beacon signals in a spread spectrum radio communication system is selectively operable in one of two modes. The first mode employs a local reference timing signal, while the second mode employs a GPS-derived reference timing signal. Preferably, the first mode identifies a baseline beacon signal that satisfies a constraint based upon time delays for detected beacon signals which are indicative of the relative distance of the transmitting base stations, thus providing selection of a baseline beacon signal that originates from a relatively close base station. The index of the baseline beacon signal is recovered and then used together with relative timing derived from the local reference timing signal to assign indices to other detected beacon signals.

Abstract: A radio receiver includes a plurality of antenna elements for receiving a radio signal from a radio transmitter; a setting part changing an impedance of at least one of the plurality of antenna elements according to an instruction signal; a measuring part measuring a change in throughput in a received signal caused due to the change in the impedance; and an instruction part providing the instruction signal which is changed in response to the measurement result.

Abstract: A radio communication system having a radio base station controller which is connected to a plurality of base stations, and assigns a fixed channel to each of the radio mobile stations. The radio base station controller also controls the beam patterns of the radio base stations to communicate with the radio mobile stations. The radio base station controller, when transmitting to and receiving from the different radio mobile stations to which the same channel is assigned, controls the beam patterns so that the channels do not interfere with each other.

Abstract: A wireless communication method includes the steps of: calculating a transmission block number-related condition necessary for enabling a receiving terminal to receive all the blocks of broadcast control channel information based on the total number of the blocks and a transmission block number; calculating a rotation angular velocity-related condition based on the foregoing condition, a block unit time, and a coverage angle; and controlling a first directional antenna to rotate a beam at a rotation angular velocity decided based on the condition relating to the rotation angular velocity of the beam.

Abstract: A method and apparatus are provided that allows beamforming to be used on a user-specific signal together with a sector-wide pilot signal in a communication system, such as a CDMA system. In one embodiment, the invention includes a plurality of elements in a defined order to transmit spatially directed signals to specific receiving radio terminals, and a single element, substantially in the center of the ordering to transmit a single pilot signal simultaneously to a plurality of receiving radio terminals.

Abstract: A signal processing unit carries out signal processings necessary for a receiving/transmission processing of an adaptive array antenna. The signal processing unit also carries out a signal processing necessary for determining phase errors in quadrature modulation and quadrature detection to be done by radio units, namely, for determining a rotation amount of an initial phase correction value. The radio units in a base station apparatus carry out frequency conversion processing, amplification processing, quadrature modulation processing, quadarture detection processing, A-D or D-A conversion processing and the like between the baseband signals and radio frequency signals. An initial phase correction value determining unit determines rotation amounts of initial phase correction values, based on power-measuring received signals inputted from the radio units, and outputs to the signal processing unit as initial phase correction value signals.

Abstract: System and method for improving the interference resistance of an radio frequency (RF) antenna system through passive prescreening of the RF energy incident upon the antenna. The invention physically partitions the RF environment into two or more sectors with respect to the direction of arrival of incident energy. The power level of the RF frequencies of interest incident upon each sector is determined such that whenever the power level exceeds a given threshold, the received signal from energy incident on that sector is modified.

Abstract: An antenna apparatus, which can increase capacity in a cellular communication system or Wireless Local Area Network (WLAN), such as an 802.11 network, operates in conjunction with a mobile subscriber unit or client station. At least one antenna element is active and located within multiple passive antenna elements. The passive antenna elements are coupled to selectable impedance components for phase control of re-radiated RF signals. Various techniques for determining the phase of each antenna element are supported to enable the antenna apparatus to direct an antenna beam pattern toward a base station or access point with maximum gain, and, consequently, maximum signal-to-noise ratio. By directionally receiving and transmitting signals, multipath fading is greatly reduced as well as intercell interference.

Abstract: A vertically integrated Ka-band active electronically scanned antenna including, among other things, a transitioning RF waveguide relocator panel located behind a radiator faceplate and an array of beam control tiles respectively coupled to one of a plurality of transceiver modules via an RF manifold. Each of the beam control tiles includes a respective plurality of high power transmit/receive (T/R) cells as well as dielectric waveguides, RF stripline and coaxial transmission line elements. The waveguide relocator panel is preferably fabricated by a diffusion bonded copper laminate stack up with dielectric filling. The beam control tiles are preferably fabricated by the use of multiple layers of low temperature co-fired ceramic (LTCC) material laminated together.

Abstract: A phased array antenna includes a transmission line network, e.g. optical or coaxial cable network, and a reference signal generator to provide a reference frequency signal to each of the antenna radiating elements. A phase calibrator generates a calibration signal. e.g. a swept frequency signal, on the transmission line network which is also reflected to create a reflected calibration signal. The phase calibrator determines a frequency difference between the calibration signal and the reflected calibration signal at each of a plurality of taps, and outputs a delay measurement signal to the antenna radiating elements, e.g. via an antenna controller, for adjusting a phase of the reference frequency signal.

Abstract: A phased array antenna includes a plurality of assemblies, each assembly including a plurality of elements and a plurality of digitally controlled centralized beam formers coupled to respective ones of the plurality of elements. The digitally controlled centralized beam formers may be disposed under the plurality of radiating elements and may be operable to provide a first signal to the respective ones of the plurality of radiating elements representative of a plurality of signals of a first polarization and a second signal representative of a plurality of signals of a second polarization. A method for distributing signals to a radiating element of a phased array antenna includes the steps of generating a first signal representative of a plurality of signals of a first polarization at a digitally controlled centralized beam former, and distributing the first signal to the radiating element.

Abstract: Techniques for simultaneous measurement of multiple array elements of an array antenna. The array is illuminated with a coherent signal source, and each array element phase shifter is cycled through a range of phase shifter settings at a unique rate. The phase shifted signals from each array element are combined to provide a composite signal. The composite signal is processed to extract the phase of the coherent source signal as received at each element. The phase information is used to determine the location of the elements relative to each other.

Abstract: A control technique for a communication system in which a microcell base station is co-located with a macrocell base station. The microcell base station tracks hot spots as they move within the macrocell. The microcell base station may utilize a two-dimensional (2-D) antenna array, which is co-located with the macro cell antenna. The two-dimensional antenna is steerable in both the horizontal and vertical directions. The size of the microcell coverage area depends upon the distance from the cell site antenna as well as the dimensionality of the array, which determines the angular spread of the beam. Filter tap weights may be adjusted to point the beam to any desired location in the macrocell. The orthogonality between the macrocell and the microcell may be obtained either in the frequency domain or in the code domain, depending upon the system in which it is implemented.

Abstract: A communication system including an antenna array with feed network coupled to communication electronics. In one example, a communication subsystem comprises a plurality of antennas each adapted to receive an information signal and a plurality of orthomode transducers coupled to corresponding ones of the plurality of antennas, each OMT is adapted to provide at a first component signal having a first polarization and a second component signal having a second polarization. The communication subsystem also comprises a feed network that receives the first component signal and the second component signal from each orthomode transducer and provides a first summed component signal at a first feed port and a second summed component signal at a second feed port, and a phase correction device coupled to the first and second feed ports and adapted to phase match the first summed component signal with the second summed component signal.

Abstract: A receiving array antenna with a variety of channels for converting received signals from receiving antenna elements (ANT) into an intermediate frequency signal (ZF) by using a circuit having one or several preamplifiers (LNA) and a mixer (MIX) connected in series, whereby a centrally generated local oscillator signal (LO) and calibration signal (CAL) are supplied to the circuit. A common distribution network (VNG) is available for the central oscillator signal (LO) and calibration signal (CAL), which is interconnected in such a way that the central local oscillator signal (LO) and calibration signal (CAL) is coupled into the circuit at the output of the receiving antenna element (ANT).

Abstract: Systems and methods provide intermodulation reduction techniques for multiple beam phased array antennas. For example, in accordance with an embodiment of the present invention, an optimization approach is employed to determine array element excitations that reduce IM interference.

Abstract: A method for calibrating a reception signal in a smart antenna system includes: locally generating a reference signal, converting the reference signal into an RF signal, and dividing the RF signal into as many signals as the number of antennas. Phase information of the divided RF signals is then detected. This is followed by outputting a plurality of reference signals having the same phases by performing phase shifting operation, converting an RF signal into a baseband signal, and calibrating the baseband signal by multiplying the baseband signal by a calibration vector. An apparatus for calibrating a reception signal in a smart antenna system includes a reference signal generating unit and an array antenna unit. The reference signal generating unit includes a local reference signal generator, an RF converter, a splitter, a phase detector, and a phase shifter. The array antenna unit includes an antenna, a front-end part, an RF transmitter, an RF receiver, and a baseband processor.

Abstract: Co-channel interference in a wireless network is identified and quantified. Rather that using color code identification, a more reliable identification property of each co-channel component of the received composite signal is used, namely, the time of arrival of a known part of a signal. Detection and timing measurement is performed even in presence of stronger signals by focusing selectively on bursts having fixed contents (e.g., the FCCH burst used in GSM for frequency correction). The repetitive measurements of the time-of-arrival of each of the interfering components of the signal during a drive test enables determination of the geographical location of the interfering co-channel base stations.

Abstract: Methods of scheduling optimization of communications used with Wireless Local Area Network (WLAN) equipment that employs steerable directional antennas. The methods may use and are compatible with Media Access Control (MAC) layers of IEEE 802.11 group of standards. The methods do not depend on any particular PHY layer standard.

Abstract: An antenna system and method for constructing said system from a plurality of antenna elements. An antenna system radiation pattern function is specified. The antenna elements are determined by measurement, simulation or calculation and parameterized according to interelement spacing within the array. The parameterized array elements are collected to form a set that is identified with a frame. A dual frame to the element frame is determined and antenna element weights are computed based on the dual frame and the specified system radiation pattern function. The antenna system is then constructed in accordance with the antenna element weights. The antenna element frame enables high-quality low SLL beams, irregular interelement spacing, arbitrary geometries of linear and planar arrays, time and space arrays, multi-band arrays and inclusion of element phase variations due to differences in element feeds in the constructed antenna system.

Abstract: A method and system for detecting a plurality of objects. The method includes steering a first beam-forming system to a first direction. The first direction is associated with a first object. Additionally, the method includes steering a second beam-forming system to a second direction. The second direction is associated with a second object. Moreover, the method includes receiving a first plurality of signals, and receiving a second plurality of signals. Also, the method includes generating a first combined signal, generating a second combined signal, dividing the first combined signal, and dividing the second combined signal. Additionally, the method includes generating a first output signal and generating a second output signal. The first output signal is associated with the first object, and the second output signal is associated with the second object.

Abstract: A radiating antenna capable of generating or receiving radiation using a plurality of feeds and a dielectric resonator is disclosed. The purpose of using multiple feeds with a single dielectric resonator antenna is to produce several beams each having a ‘boresight’ (that is, a direction of maximum radiation on transmit, or a direction of maximum sensitivity on receive) in a different direction. Several such beams may be excited simultaneously to form a new beam in any arbitrary direction. The new beam may be incrementally or continuously steerable and may be steered through a complete 360 degree circle. The invention may be combined with an internal or external monopole antenna so as to cancel out the antenna backlobe or otherwise resolve the front/back ambiguity that arises with this type of dielectric resonance antenna. When receiving radio signals, electronic processing of such multiple beams may be used to find the direction of those signals thus forming the basis of a radio direction finding device.

Abstract: A method for enhanced Capon beamforming includes the steps of providing a sensor array including a plurality of sensor elements where an array steering vector corresponding to a signal of interest (SOI) is unknown. A covariance matrix fitting relation is bounded for the unknown array steering vector by constraining the array steering vector using a constant norm and a spherical uncertainty set. The matrix fitting relation is then solved to provide an estimate of said array steering vector.

Abstract: A true-time delay feeder for multiple aperture beam steering devices. The feeder comprises a plurality of tunable time delay modules. The tunable time delay modules provide different delays to different beamlets without changing the spectrum of each beamlet. The tunable true-time delay modules provide for temporal synchronization and spatial coherence of the beam front.

Abstract: A wireless local area network and location system for locating objects within a monitored environment are disclosed. A plurality of access point stations receive and transmit communication signals within a wireless local area network. A processor is operatively connected to each of the access point stations and operative for processing communication signals received from the mobile station and, in one embodiment, determining which communication signals are first-to-arrive signals and conducting differentiation of the first-to-arrive signals to locate a mobile station. Delayed versions of at least one interference signal are weighted and the amplitude and phase controlled with weighted functions W1, W2 . . . Wn. The resultant weighted replicas are summed to determine an approximation of disbursed interference for cancelling interference. The location system can include a tag transmitter and spaced monitoring receivers and processor.

Abstract: A chirp-based method and apparatus measures phase variation through a reference frequency transport cable for a phased array antenna. A chirp is injected into the a signal transport path from a remote transmit/receive portion of the antenna, so that the chirp is conveyed over the signal path, reflected from an upstream bandpass filter at a local transmit/receive portion of the antenna, and returned to a remote transmit portion of the antenna. Energy in the returned chirp is extracted by a downstream bandpass filter and correlated in a delay lock loop with energy in an auxiliary chirp signal, that is delayed relative to the injected chirp. The delay of the auxiliary chirp is adjusted to maximize the correlation output and provide an indication of the delay through the signal path.

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: Substantial improvements in frequency reuse in microwave communications systems is achieved by canceling co-channel interference and transmitter leakage. Interferometric beam-narrowing reduces beamwidth without reducing preak magnitude of the beam pattern. Frequency-dependent beam-shaping compensates for frequency-dependent distortions of the beam pattern thereby improving bandwidth. A spatial demultiplexing technique utilizes spatial gain distributions of received signals to separate signals, even from co-located transmit sources, and uses microwave lensing to enhance received spatial gain distributions. Predetermined cross-polarization interference is used to separate differently polarized receive signals. A reference branch provides a cancellation signal to a receiver to cancel transmitter leakage signals. An error signal controls an impedance-compensation circuit that is responsive to changes in antenna impedance but not to receive signals.

Abstract: A receiver for a digital beamforming radar system includes a plurality of antenna elements, low-noise block converters, one or more analog-to-digital converters, and a processor. The antenna elements receive a radar signal and output a received signal. The low-noise block converters are modified commercially available components used in satellite television systems, respond to the received signal from a corresponding antenna element, and output an intermediate frequency signal. The low-noise block converters include at least one amplifier, a mixer, and a local oscillator input. The local oscillator input enables an external local oscillator signal to be inputted to the mixer. The analog-to-digital converters are responsive to the intermediate frequency signal of a corresponding low-noise block converter. The processor is responsive to the digital signals output by the analog-to-digital converters.

Abstract: A technique for suppressing interference with unknown phase shifts received by an array of sensor elements partitions the array into a plurality of subarrays. Each subarray is processed independently to suppress the interference. Next, the resulting data from each subarray are summed together. This summed data, which effectively represents data provided by the full array with interference suppressed, may be utilized to detect and/or localize a target of interest. Each subarray is processed independently of all other subarrays. No cross-subarray processing is required. This technique is applicable to linear arrays, multi-line arrays, planar arrays, cylindrical arrays, conformal arrays, and spherical arrays. Applicable sensors include acoustic sensors (e.g., sonar, ultrasonic), electromagnetic sensors (e.g. radar), and optical sensors (e.g., infrared, ultraviolet, visible light).

Abstract: A chirp-based arrangement derives a measure of phase variation through a reference frequency transport cable of a phased array antenna architecture, such as a spaceborne synthetic aperture radar system. A direct digital synthesized chirp signal is injected in an upstream direction into the transport cable from a downstream end thereof, so that the chirp signal is transmitted in an upstream direction, reflected from an upstream bandpass filter, and returned in a downstream direction. At each of a plurality of nodes that are distributed along the transport cable, the two chirp signals are extracted and frequency domain-processed to derive said measure of transport delay through the cable between the source of the reference frequency signal and each of the nodes.

Abstract: A power system for a phased-array radar system powers an antenna array with a single multiphase transformer. A plurality of AC/DC converters are connected in parallel between the single multiphase transformer and a common bus. The common bus is balanced with respect to chassis ground reducing noise and improving operating safety of the antenna. The AC/DC converters each has a multi-sloped characteristic which enables the converters to share power by modifying output impedance as a function of load without external control signals. The system also has several layers of fault detection.

Abstract: In the hardware-efficient demodulator for a CDMA adaptive antenna array mechanism of a mobile radio communication system, a correlators bank receives digital baseband signals received through an antenna array of a base station and computes correlation values with a local code sequence. A beamformer receives the digital baseband signals and the correlation values from the correlators bank and calculates beamforming weight vectors. A searchers bank receives the digital baseband signals and calculates an initial acquisition and reliable timing information for a multipath search by a common work with the beamformer, which uses a beamforming algorithm. A beamforming complex multiplier for a finger performs a complex multiplication for the beamforming weight vectors and the digital baseband signals, and sums up them.