Abstract: Disclosed is a spread spectrum clock generator which includes: a first delay control type oscillator that variably controls an oscillation period at a control period interval according to a control signal; a control circuit; a maximum modulation value determination circuit that determines a maximum modulation value from a predetermined value, a frequency control signal, and a given modulation degree setting signal; a modulation signal generation circuit that receives the maximum modulation value from the maximum modulation value determination circuit and generates a modulation control signal within the maximum modulation value; and a second delay control type oscillator that receives a value obtained by adding the modulation control signal from the modulation signal generation circuit to the frequency control signal as a control signal and variably controls the oscillation period of an output clock signal at the control period interval according to the control signal.

Abstract: Channel quality can be detected accurately in a wireless transmission system such as an HSDPA method. In the case of estimating a channel quality of a signal transmitted by a Code Division Multiple Access method and of estimating the channel quality in a system having a synchronization channel not orthogonal to a channel receiving data, a noise component of a desired channel is estimated; degree of a noise component caused by the synchronization channel is estimated with respect to the estimated noise; and a channel quality of a receiving channel is detected based on the estimated degree of the noise component.

Abstract: An apparatus and method for channel estimation and CP reconstruction in an OFDM-STBC mobile communication system are provided. An ISI canceller cancels ISI signal components from first and second received symbol sequences. A cyclicity restorer cancels ICI signal components from the ISI-cancelled first received symbol sequence and the ISI-cancelled second received symbol sequence. A recoverer acquires the recovered sequence estimates of the ICI-cancelled first received symbol sequence and the ICI-cancelled second received symbol sequence by decoding. The ICI cancellation of the ISI-cancelled first and second received symbol sequences and the ISI cancellation of the second received symbol sequence are iterated a predetermined number of times.

Abstract: A code division multiple access (CDMA) communication system using spread spectrum signaling over a communication bandwidth uses two different signal spectra generated using two different respective spreading code formats, such as NRZ code formatting and staggered Manchester code formatting, for respectively providing nonsplit spectra having a center peak and split spectra having a center null. The spectra are combined during transmission as a CDMA communication signal having a composite spectrum. The use of different code formats produces the composite spectrum of respective center peak and center null spectra that enables increased channel capacity.

Abstract: A method and a standard radio wave receiver for receiving a plurality of standard radio waves respectively having signal configurations in accordance with respective specifications which define carrier channels and formats and for decoding time code signals carried by the standard radio waves. The method extracts at least part of a bit waveform common to the specifications as a extracted signal from a waveform of each of the time code signals given by each of the carrier channels, synchronizes bits to each of the time code signals in accordance with the extracted signal, determines an evaluation index indicating good or bad of a reception condition for each of the carrier channels from the bit waveform, and selects a single channel from the carrier channels in accordance with the evaluation index.

Abstract: An ultra wideband (UWB) receiver system operable to process a high order Gaussian pulse includes an integrator group, a correlator circuit and a comparator circuit. The integrator group includes an input coupled to receive the high order Gaussian pulse and an output coupled to the correlator circuit, the integrator group having two or more successively coupled integration stages, each integration stage operable to integrate, over a predefined time period, the signal received thereby, the integrator group operable to output, in response, a lower order Gaussian pulse. The correlator circuit is coupled to receive the lower order Gaussian pulse, and is operable to output a correlated output signal corresponding to the correlation between the lower order Gaussian pulse and a predefined reference signal.

Abstract: The invention relates to a spread-signal multiplexing circuit for frequency-multiplexing a plurality of spread signals that were generated in parallel according to the SSMA scheme. An object of the invention is to adapt to various degrees of multiplicity and to keep the SN ratio and the power efficiency high. To this end, a spread-signal multiplexing circuit of the invention comprises an amplitude monitoring part for multiplexing a plurality of spread signals and determining amplitude of a resulting signal in time-series order; a delaying part for delaying the spread signals in parallel by a time that is equal to a propagation delay time of the amplitude monitoring part; and a multiplexing part for generating a multiplexed signal by multiplexing the delayed spread signals while weighting the delayed spread signals in parallel using weights that are smaller as an average value of the determined amplitude is larger.

Abstract: In the method of processing signals, multi-path signals are received, channel estimates for the received multi-path signals are determined, and a combining operation is applied to the multi-path signals, the combining operation being a function of a correlation matrix of the received multi-path signals, a correlation matrix of estimates for channels of the received multi-path signals, a cross-correlation matrix of the channels and channel estimates for the received multi-path signals, and the channel estimates.

Abstract: A method of generating a composite signal includes the steps of: (a) generating a plurality of sub-carriers, each sub-carrier having a different frequency position in a frequency spectrum; (b) generating a plurality of codes; and (c) forming a plurality of code combinations from the plurality of codes generated in step (b). The method also includes the steps of (d) first modulating each sub-carrier using a respective one of the code combinations formed in step (c) to form a plurality of modulated sub-carriers; and (e) second modulating in-phase and quadrature components of a base carrier using the plurality of modulated sub-carriers to form the composite signal having multiple carriers. The composite signal is a constant envelope signal, and a single sideband signal.

Abstract: A method and apparatus for utilizing a switched beam directional antenna in a wireless transmit/receive unit (WTRU) is disclosed. A wireless communication system includes a serving cell, a neighbor cell and a WTRU. The WTRU is configured to generate and steer a directional beam in a plurality of directions. Once the WTRU registers with the wireless communication system, the WTRU receives messages transmitted by the serving cell. The WTRU measures signal quality of messages received in each of a plurality of predetermined directions while steering the directional beam antenna. The WTRU selects a particular one of the directions having the best signal quality. As the WTRU constantly moves, the WTRU monitors signal quality in the selected direction, and switches to another direction when the signal quality in a current direction drops below a predetermined threshold.

Abstract: A power gated variable hop cycle beam laydown (700) manifests itself as first cells (C, D) supported by a first hop cycle, second cells (G, H) supported by a second hop cycle, and transition cells (E, F) supported by a transition hop cycle. The transition hop cycle uses power gating to transition the laydown (700) from cells (C, D) operating at the first hop cycle to cells (G, H) operating at the second hop cycle. To this end, the transition hop cycle power gates its downlink beam for a portion of time needed to reduce interference between nearby (e.g., adjacent) cells.

Abstract: A monopulse radar operating at low angles of elevation (LOE) receives returns from a target by a direct path and by a path including a reflection from that portion of the Earth's surface lying between the radar and the target. The surface-reflected signal tends to cause errors in the estimate of the elevation of the target. A radar system directs at least upper and lower overlapping beams at LOE toward the target for receiving returns. The upper and lower beams may be sequential or simultaneous. Real and imaginary portions of the sum (?) and difference (?) signals are generated for each beam. The monopulse estimates of elevation ê derived from the real portion of the ? and ? signals are processed to produce correction signals for upper and lower beams. Each correction signal is weighted and summed to correct the estimate of elevation.

Abstract: The number of times for averaging operation for averaging a correlation value of a received signal and a reference signal is properly controlled. When the correlation value is not averaged, since a lower limit value TH_A of a correlation level of a distribution of timings of which a path exists is larger than an upper limit value TH_B of a correlation level of a distribution of timings of which a path does not exist, the correlation value of a path is hidden by noise. Since the averaging operation is repeated until the relation of TH_A>TH_B is satisfied, the averaging operation is stopped when the relation is satisfied. The TH_A and TH_B are decided in accordance with RSCP and ISCP of a pilot channel and RSSI of a received base band signal.

Abstract: A method of Partial Parallel Interference Cancellation (PPIC) is provided for recursively eliminating the Multiple Access Interference from a received signal. Such method is to use a recursion way to eliminate all the Multiple Access Interference (MAI) one by one from the received signal. Moreover, the present invention is to take the output of the pre-stage as the input of the present stage with the recursion method so that we can use only one operating circuit to obtain the function the MAI eliminating.

Abstract: A beam-forming apparatus and method for improving system performance using a spatial interpolation and at least one Angle of Arrival (AoA) in a system based on regular spatial sampling is provided. The AoA is estimated using a carrier-to-interference ratio. Beam-forming angles are distributed and steered in a predefined scheme such that an identical process is applied in all directions. According to this steering, a linear system model is computed based on regular spatial sampling using regular spatial separation at beam angles. Beam-forming performance is improved by compensating for a difference between adaptive and sector-type arrays. Only the steps of computing a spatial interpolation and determining an angle range for beam-forming using at least one AoA are added. The precision of estimating an AoA and the precision of beam-forming increase without an additional antenna. Because the system is simpler than that of an adaptive beam-forming system, significant gain is obtained.

Abstract: An optical subscriber system according to the present invention has an adaptive antenna having a plurality of antenna elements, for controlling the weighting on the antenna elements thereby to radiate beams that are adapted to radio wave environments, a position estimator for estimating the position of a mobile unit, a beam combiner for weighting signals received from the mobile unit by the antenna elements and combining beams, and a weighting coefficient generator for correcting weighting coefficients adapted to radio wave environments, which give initial weights as weights to form nulls in bearings other than the mobile unit based on the position of the mobile unit which has been estimated by the position estimator, for thereby reducing a time required for convergence.

Abstract: The disclosed embodiments relate to a system and method for providing user specific beams in a fixed beam network. In one embodiment, there is provided a mobile transceiver comprising a first device configured to receive phase reference signal data from a base station, the phase reference signal data being indicative of a first phase reference signal and a second phase reference signal that may be used by the mobile transceiver during a communication session, and a second device configured to determine whether the second phase reference signal is likely to provide improved reception between the base station and the mobile transceiver with respect to the first phase reference signal, wherein the second device is configured to transmit data to the base station, the data being indicative of whether the first phase reference signal or the second phase reference signal is likely to provide improved reception between the base station and the mobile transceiver.

Abstract: A system for generating a pseudomonopulse tracking error includes an antenna system (401) that generates a sum antenna beam and a difference antenna beam. The sum antenna beam has a pattern with a peak gain on the boresight axis, and the difference antenna beam has a pattern that is circularly symmetric and forms a null about the boresight axis. The difference antenna beam has a relative phase that varies 360 degrees around the boresight axis. A differential phase dispersion is provided as between the sum and difference RF channels (405, 407) to providing a rotating scanning plane (702).

Abstract: A method and apparatus for generating accurate estimates of a radar target's azimuth and elevation angles for a phased-phased array rotating radar. Scan modulated coherently integrated (SMCI) monopulse curves are generated from a measured one-way transmit antenna pattern and three receive antenna patterns. The SMCI monopulse curves are calculated in advance for the expected beam steers. To utilize the SMCI monopulse curves, two-way Sum, Delta-Azimuth and Delta-Elevation target returns are coherently integrated, the target's monopulse ratios calculated, and the SMCI monopulse curves or polynomials used to calculate the target's U-offset and V-offset sine-space angles, which are added to the radar's beam steer to get an improved estimate of the target's sine-space angular position denoted as Utgt and Vtgt. A coordinate system transformation transforms Utgt and Vtgt to azimuth and elevation angles in a non-rotating coordinate system.

Abstract: An automotive radar system includes a beamformer circuit and a beamcombiner circuit. The beamformer circuit forms a plurality of antenna beams at a plurality of beam ports. The beam combiner circuit receives the beams provided thereto from the beamformer circuit and combines the beams to provide a desired number of beams, with each of the beams having a desired beam shape. In one embodiment, the beamcombiner provides first and second end beams having a beamwidth which is less than a beamwidth of middle beams.

Abstract: A method of controlling multiple antenna signal transmission is disclosed. The method includes adjusting signal parameters so that transmission signals from a plurality of antennas combine to form a directional beam. A time duration in which the transmission signals are directed is controlled so that an average EIRP does not exceed a predetermined threshold.

Abstract: An antenna steering algorithm for a smart antenna uses signal quality metrics and link quality metrics for selecting a preferred antenna beam. The link quality metrics supplement the signal quality metrics for improving the antenna steering decision. The link quality metrics are based on information available from existing counters operating in the media access control (MAC) layer. Separate estimates of the frame error rates in the receive links and in the transmit links are obtained. One estimate is the downlink quality metric (DLQM) and another estimate is the uplink quality metric (ULQM). Alternative link quality metrics are based on throughput and data rates of the exchanged data.

Abstract: A radar system with a radar sensor (10) which comprises a transmitting module (20), a receiving module (22) and a supply network (64), wherein the transmitting module (20) comprises a first plurality of partial antennas (26, 28, 30, 32, 34) and the receiving module (22) comprises a second plurality of partial antennas (46, 48, 50), and wherein the supply network (64) operates at least one partial antenna (30) of the transmitting module (20) together with at least one partial antenna (48) of the receiving module (22) in a first operating mode, to obtain a first, low angular resolution, and wherein the supply network operates one group of partial antennas (26, 28, 30, 32, 34) of the transmitting module (20) together with a group of partial antennas (46, 48, 50) of the receiving module (22) in a second operating mode to obtain a second high angular resolution.

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 method and apparatus for estimating elevation angle when using a broad search beam such as a cosecant-squared beam is provided. The range of a target detected during a search with a broad beam covering a broad angular search area is determined. Based on the determined range, consecutive beams are transmitted at increasing search elevation angles in the broad angular search area. Echo signals of the consecutive beams are used to determine an elevation angle estimate for the target.

Abstract: A method and apparatus for simultaneously transmitting, at a common frequency, a plurality of signals on a plurality of beams from a phased array antenna involves forming composite signals that contain the plurality of signals. The composite signals correspond to respective antenna elements in the antenna array and include at least a first signal for transmission via a first transmit beam and a second signal for transmission via a second transmit beam. The phases of the composite signals are a function of signal modulations of the first and second signals and phases of the respective antenna elements required to form the first and second transmit beams. By digitally forming the composite signals, taking into account the modulation phase and beam-forming phase of each signal at each antenna element, hardware requirements are reduced and efficient, saturated amplifier can be employed.

Abstract: A monopulse radar system for detecting an azimuth depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, includes: a transmitting array antenna and a receiving array antenna each including antenna elements forming an antenna train, at least one antenna switch disposed among the elements of the transmitting array antenna and/or the receiving array antenna, and a switch controller for turning ON/OFF the antenna switch to change an aperture length of the transmitting array antenna and/or the receiving array antenna thereby changing a beam shape thereof. The antenna elements of the transmitting array antenna and the receiving array antenna are formed on a dielectric substrate. A dielectric length between the antenna train formed by the antenna elements and the antenna switch is ½ dielectric wavelength.

Abstract: The present invention describes a communication system comprising a primary radio station (PS) and at least one secondary radio station (SS), intended to be in motion (MOT). The secondary radio station has at least one controllable structure (CS) for communicating with the primary radio station, and control means (CONT) for controlling the controllable structure depending on the movements of the secondary radio station. The control means of the controllable structure comprise magnetic field sensors (MFS) and gravitational field sensors (GFS) for providing measurements of the earth magnetic (H) and gravitational (G) fields, and computing means (COMP) for computing control information from these measurements. The computing means read the outputs of each sensor and make the calculations required to control the controllable structure at appropriate time intervals depending on the motion state of the secondary radio station.

Abstract: Disclosed is a control apparatus capable of more effectively utilizing radio resources. Mobile stations positioned close to each other are treated as one group, and a direction and width (radiation angle) of a beam radiated from an adaptive array antenna 11 is controlled for each group so that one beam capture one group. To be concrete, a plurality of mobile stations are classified into groups by a classification section 19, and an area to which each group moves is estimated by a directivity determination section 20. The adaptive array antenna 11 is controlled by the directivity control section 15 so that one beam can cover an area in which one group is positioned and the area to which this one group moves.

Abstract: To realize a monopulse radar system wherein the velocity of a mobile body, distance between an obstacle and the mobile body and relative velocity can be detected and simultaneously, the direction of the obstacle can be detected, in a monopulse radar system wherein an azimuth is detected depending upon amplitude difference or phase difference between signals respectively received by plural receiving antennas, an array antenna composed of plural antenna elements is used for each transmitting antenna and each receiving antenna, at least one of the transmitting antenna and the receiving antenna is provided with an antenna switch for switching an antenna beam shape to a short angle/long distance or a wide angle/short distance and a switch control device that controls the switching of the antenna switch is provided.

Abstract: Amplitude phase distortion adding sections are provided for the power amplifiers on the antenna arrays greater in amplitude weighting while amplitude distortion adding sections are provided for the power amplifiers on the antenna arrays smaller in amplitude weighting. Due to this, because a required amount of distortion compensation is made based on each antenna array, there is no bad effect upon the adjacent other antenna array, suppressing the deterioration in beam control accuracy. This, also, reduces the size of the apparatus and improves the power efficiency on the array antenna apparatus overall.

Abstract: A calibration method, which allows calibration with high precision and which can perform calibration normally even when a specific radio receiving portion has a problem, and an array antenna receiving apparatus using the method. The array antenna receiving apparatus multiplexes calibration signals having predetermined symbol patterns from a multiplexing circuit (103) to signals received by array antennas (101) and inputs the results to radio receiving portions (104). The calibration signals having passed through the radio receiving portions are extracted by a calibration signal extracting portion (110), and an SIR detecting portion (111) determines one of the radio receiving portions having the best receiving quality as a reference branch based on the calibration signals.

Abstract: The beam pattern associated with a multi-beam antenna array is adjusted if a first beam of the beam pattern is overloaded. A lobe of a second beam of the beam pattern can be steered away from a main lobe of the first beam. Also, if a user is located in an area covered by a second beam which is adjacent to the first beam, a third beam of the beam pattern can be selected for effectuating communication with the user. If a user is located in an area covered by the first beam, another beam of the beam pattern can be selected for effectuating communication with the user.

Abstract: A method and system for are provided for detecting one or more radar targets of interest in the presence of jamming signals. A plurality of sub-arrays are formed from an antenna array. Sub-array beams are adaptively formed so as to point one or more nulls in one or more respective directions corresponding to one or more jammers. A super-resolution technique is applied to determine a count of the one or more radar targets and to determine the corresponding direction of arrival.

Abstract: An antenna array system with dynamic signal routing to a set of receivers. A monopulse electronically scanned antenna (ESA) has a plurality of antenna elements divided into subarrays. ESA beam steering phase shifters are associated with the respective subarrays of antenna elements, such that the output signals from the respective antenna elements associated with the respective quadrants are phase shifted and summed to provide respective subarray signals. A monopulse network responsive to the subarray signals provides monopulse outputs to a set of receivers. A beam steering controller provides phase shift commands to the ESA phase shifters to set the phase shift associated with the respective phase shifters of the subarrays. The controller commands the ESA phase shifters to modulate the phase shift of selected quadrants.

Abstract: In a transmission antenna directivity control apparatus, a reception multi-beam generation section executes weights and combines reception signals from reception array antenna elements using a preset weight coefficient to generate reception multi-beams. A transmission weight coefficient generation section generates, in accordance with detection powers of the reception multi-beams, a transmission weight coefficient for transmission data in correspondence with each of transmission multi-beams corresponding to transmission array antenna elements. A transmission multi-beam generation section multiplies the transmission data by the transmission weight coefficient to generate the transmission multi-beams and supplies them to the corresponding transmission array antenna elements.

Abstract: A control device for the formation of plural simultaneous radar reception beams in an electronic scanning antenna. The electronic scanning antenna includes an array of detectors of a reception microwave signal arranged in n columns and m rows. The control device makes, in the microwave domain, a first partial combination of the signals received, the first combination being made according to each column. An optical device makes a second partial combination in the optical domain, the optical device including at least n optical sources each producing an optical signal modulated at the frequency of the reception microwave signal by an associated microwave combination signal. The optical signal is divided into r optical signals to obtain nxr optical signals.

Abstract: A near-field calibration arrangement for an antenna array determines the phase shifts or attenuation of the elemental control elements of the array. The calibration system includes a probe located in the near field, and a calibration tone generator. The tone generator is coupled to the probe in the case of calibration of a receive antenna, and to the signal port of the array in the case of calibration of a transmit antenna. A code generator generates sets of values, with each set being orthogonal to the others. The codes are applied to the control input port of the array antenna, so that the codes encode the tone passing through the antenna. The encoded tones are applied to a decoder and processor, which processes the signals to determine the phase shift or attenuation associated with each bit of the control signal. A transmit antenna attitude determination or pointing arrangement uses the calibration tone generator in conjunction with a plurality of remote sites.

Abstract: A method of operating a radar to track echo signals from a target in the presence of a barrage jammer is shown to comprise the steps of actively determining the apparent direction of the combination of echo signals from a target and jamming signals, passively determining the actual direction and average power of a barrage jammer, calculating, from the foregoing, the actual direction of the target and instituting range and angle tracking of the target when the target is clear of the jamming signals.

Abstract: A switch (10) having a beam-forming network (12) generates independently steerable beams (26). One or more of the independently steerable beams couple in radiating communication with selected ones of M beam ports (18). A feeder array (11) or second beam-former (13) provides signals to radiating elements 19 to form multiple antenna beams for communication.

Abstract: A digitally beam formed phased array antenna capable of both transmitting and receiving signals is constructed from a series of digitally controlled antenna elements. To transmit signals, a series of direct digital synthesizers is used to drive the antenna elements forming the phased array. Each direct digital synthesizer is programmed from a common digital processor with specific time and phase delay information such that the signals from the array combine to form a desired antenna pattern. To receive signals, signals from each antenna element in the phased array are processed by analog to digital converter. The digitized signals are then pre-processed in a time and phase delay preprocessor which receives time and phase delay information from a corresponding direct digital synthesizer prior to signal combining in a common digital processor.

Abstract: An array antenna radar apparatus has a single front end shared by a plurality of antennas, a first switch for cyclically connecting the antennas to the front end at a prescribed switching frequency, and a second switch for cyclically connecting the output of the front end to frequency converters corresponding to the antennas. The frequency converters frequency-convert intermediate-frequency signals of the respective antennas output by the front end to baseband signals at the switching frequency. Phase shifters and amplitude adjusting units apply a phase shift or amplitude adjustment to the outputs of the frequency converters and combine the resulting signals, thereby making it possible to detect a target in a desired direction.

Abstract: This radar with a wide instantaneous angular field and a high instantaneous angular resolution, in particular for a missile homing head, includes essentially:a transmitting antenna with a relatively wide radiation pattern, transmitting a quasi-continuous wave;a receiving antenna including a plurality of radiating elements;means for formation of beams associated with said receiving antenna, to achieve a linear combination of the signals from the various radiating elements of said receiving antenna, in order to obtain a group of simultaneous reception beams allowing the instantaneous scanning of the airspace covered by said transmitting antenna.

Abstract: The process and the corresponding phase or amplitude-single pulse radar device are used to locate a first and possibly a second target (TT1, TT2) detected by the radar beam from the direction x1, y1; x2, y2. The extended single-pulse aerial of the radar device has at least three partial aerials for a first measuring axis x (e.g. azimuth) which are arranged in such a way, have such directional characteristics and the signals of which are combined together and weighted in such a way that two mutually linearly independent, purely real or purely imaginary aerial functions which are independent of target displacements perpendicular to the first measuring axis are formed. The function course of these aerial functions F1(x) and F2(x) is measured for the individual case and the functional values dependent upon the target displacement x are stored in the storage unit (MEM). Measurements are found for the targets of the position x1 and x2 detected by the radar beam according to the aerial functions F1 and F2.

Abstract: In a phased array radar, simultaneous beam steering and single-sideband mlation is accomplished in the phase shifters in response to phase control signals produced by the beam steering controller and input to the phase shifters. The beam steering controller produces the phase control signals from a pre-selected beam steering angle, a pre-selected radar intermediate frequency and a voltage representing the frequency error from incomplete compensation of the target motion (doppler) of the previous cycle of the radar. Using the phase shifters thusly eliminates the need for an expensive separate component, the single sideband modulator.

Abstract: The disclosure relates to electronic scanning array antennas whose radiating elements are distributed within a volume instead of being distributed on a reflective surface that is plane or generated by revolution. It pertains to a method for broadening the beam of a volume antenna aimed in a direction without giving it asymmetrical deformation or substantially increasing the secondary lobes. This method consists of applying the following phase excitation law to the radiating elements of the volume antenna: ##EQU1## where .lambda. is the wavelength of the radiation transmitted or received and .rho..sub.n is the distance from the radiating element with an index n considered to a point I external to the volume antenna located on the axis of aiming direction on the side opposite the aiming direction.

Abstract: A digitally beam formed phased array antenna capable of both transmitting and receiving signals is constructed from a series of digitally controlled antenna elements. To transmit signals, a series of direct digital synthesizers is used to drive the antenna elements forming the phased array. Each direct digital synthesizer is programmed from a common digital processor with specific time and phase delay information such that the signals from the array combine to form a desired antenna pattern. To receive signals, signals from each antenna element in the phased array are processed by analog to digital converter. The digitized signals are then preprocessed in a time and phase delay preprocessor which receives time and phase delay information from a corresponding direct digital synthesizer prior to signal combining in a common digital processor.

Abstract: A four-port transmission line device that processes two incoming RF signals of arbitrary phase and amplitude to output two corresponding RF signals of equal phase and amplitude. Two sets each of two quarter-wave transmission line segments are connected in series between corresponding input and output ports. A short circuit interconnect shorts together the junctions of the two series connected line segments. A resistive element is connected across the two input ports, and another resistive element is connected across the two output ports. The short circuit interconnection forces the combination of the two input signals into one resultant signal at the short circuited junction. Out-of-phase components of the resultant signal are absorbed in the resistor across the input ports. The remaining in-phase components are divided into two outputs signals of equal phase and amplitude.

Abstract: An antenna for a base station comprising a plurality of antenna arrays (40; FIG. 6a) each capable of forming a multiplicity of separate overlapping narrow beams in azimuth, the arrays being positioned such that the beams formed by the arrays provide a coverage in azimuth wider than each array. Means are provided for splitting (58; FIGS. 14b,14c) the transmission output of a given transceiver into two signals prior to transmission power amplification and transmitting said signals in two adjacent narrow overlapping beams.

Abstract: A beam electronically steers, in real time, a multielement sensor array at radio frequencies. A sensor array is configured in one embodiment with orthogonal loops and orthogonal dipole elements. Each loop and dipole combination generates a polarized output signal which is routed, via a connection matrix, to an equal number of signal splitters. The resulting modal patterns are then routed to networks having quad hybrids and digitally user-controllable vector modulators. The signals outputted from the quad hybrids and the vector modulators of each of the networks are inputted to separate combiners. The signals outputted from the separate combiners of the networks are then recombined in combiners. The signals outputted from these combiners define the azimuth around the Z-axis, the elevation around the Y-axis, and the elevation around the X-axis, respectively.