Abstract: An antenna apparatus 1 includes: an anechoic box 50 having the internal space 51 that is not influenced by the surrounding radio wave environment; a plurality of antennas 6 that use radio signals in a plurality of divided frequency bands set in advance; a reflector 7 that is housed in the internal space and has a predetermined paraboloid of revolution, radio signals transmitted or received by an antenna 110 of a DUT 100 being reflected through the paraboloid of revolution; and antenna arrangement means 60 for sequentially arranging the plurality of receiving antennas 6 at a focal position F, which is determined from the paraboloid of revolution, according to the divided frequency bands.

Abstract: A radar system for use in a vehicle moving in a first direction may include a plurality of antenna elements spaced apart in a second direction; and a controller operably connected to the plurality of antenna elements. The controller may be configured record signals received by each antenna element at each time instant of a plurality of time instants; calculate a position in the first direction of each antenna element for each time instant based on a velocity hypothesis; calculate a virtual two-dimensional antenna array response based on the signal received by each antenna element at each time instant and the position in the first direction of each antenna element at each time instant; calculate a beamforming spectrum based on the virtual two-dimensional antenna array response; and identify a peak in the beamforming spectrum to identify an elevation angle from the vehicle to a target relative to the first direction.

Abstract: An measurement apparatus (antenna apparatus) 1 includes: an OTA chamber 50 having an internal space 51 that is not influenced by the surrounding radio wave environment; a reflector 7 that is housed in the internal space 51, radio signals transmitted or received by an antenna 110 of a DUT 100 being reflected through a paraboloid of revolution; a plurality of test antennas 6 that use radio signals in a plurality of measurement target frequency bands for measuring the transmission and reception characteristics of the DUT 100; and automatic antenna arrangement means 60 for sequentially arranging each of the test antennas 6 at a focal position F, which is determined from the paraboloid of revolution, according to the measurement target frequency bands.

Abstract: An information processing method, performed by a computer, includes: acquiring a beacon signal from a radio circuit coupled to a processor of the computer and configured to receive the beacon signal from a transmission source; calculating a length of a monitoring period, based on time intervals at which the beacon signal is received in a period of duration of a stationary state of the computer; and determining as being out of an area in proximity to the transmission source of the beacon signal in a case where the beacon signal is not received during the monitoring period having the length.

Abstract: A radar surveillance system is described in which the radar beam re-visits each area of interest after a short period of time, by electronically reconfiguring a scanned beam to an offset position for an interleaved sub-dwell, within a scan period. This ‘look-back’ capability, where the area under test is re-visited after approximately 1 second, allows the natural de-correlation of sea clutter to take place between the initial and look-back samples of the surveillance area. The re-visit time can be adjusted to best exploit the de-correlation characteristics of the sea clutter return.

Abstract: Aspects of the subject disclosure may include, for example, a transmission device that includes a first coupler that guides a first electromagnetic wave to a first junction to form a second electromagnetic wave that is guided to propagate along the outer surface of the transmission medium via one or more guided-wave modes. These mode(s) have an envelope that varies as a function of angular deviation and/or longitudinal displacement. Other embodiments are disclosed.

Abstract: A radar tracking method and system is disclosed that improves radar resource utilization and increases Doppler resolution. The method includes tracking a primary target and a secondary target by directing a radar transmit signal main lobe at a primary target, the radar transmit signal main lobe having associated radar transmit signal side lobes, and receiving a main lobe radar return signal and side lobe radar return signals. A secondary target proximate to a first side lobe radar transmit signal is identified. Then, the primary target is tracked using the radar transmit signal main lobe and the main lobe radar return signal, and the secondary target is tracked using the first side lobe radar transmit signal proximate the secondary target and an independent side lobe return beam formed to align with the secondary target.

Abstract: There is provided a radar apparatus of an electronic scan type configured to transmit an electric wave and calculate an angle of a target based on a phase difference of respective reception signals, thereby detecting a target position. An antenna unit transmits and receives the electric wave and provided with two transmission antennae. A transmission unit alternately transmits an electric wave having a first beam pattern and an electric wave having a second beam pattern from the two transmission antennae. First and second reception units calculate arrival angles and reception levels of reflected waves calculated from respective reception signals which are obtained by receiving the reflected waves by the first and second beam patterns. A comparison unit compares the reception levels by combining the arrival angles of the reflected waves. A determination unit determines whether a target actually exists at the arrival angles in accordance a comparison result.

Abstract: Methods for disambiguating the location of a radar contact using an N×M dimensioned radar array are provided. In the horizontal plane, the method comprises transmitting a first radar energy pattern in a direction, collecting reflected energy of the first radar energy pattern from the contact, transmitting a second radar energy pattern in the direction and collecting reflected energy of the second radar energy pattern from the contact. The method further comprises comparing the collected energy of the first radar energy pattern and the collected energy of the second radar energy pattern and determining if the contact is located in a side lobe or a main lobe of the first and second radar energy pattern based on the comparison. In the vertical plane, other similar embodiments may be used to determine if the radar antenna(s) are blocked by an obstacle.

Abstract: Method of automatic target angle tracking by sum-and-difference monopulse radar covers radiolocation sphere and specifically monopulse direction finding systems. It can be used in order to increase guidance accuracy, for example, for anti aircraft missiles and of unmanned aerial vehicles to radar targets such as: radio beacons; aerial vehicles reflecting the radio signal that illuminates them; aerial vehicles and ground-based devices radiating radio signals and jamming signals. The aim of the method consists in the assurance of reliability and stability and in the enhancement of guidance accuracy of automatic target angle tracking due to elimination of automatic tracking losses and great errors arising during the influence of the signals of orthogonal polarization or polarization close to it. The proposed method provides full protection from polarization jamming for all types of monopulse radars.

Abstract: What is provided is a receiver-on-a-chip comprising a monolithic integrated circuit that reduces the receiver to a cigarette-pack-sized assembly mountable directly at an antenna element, with a much-increased operational bandwidth and instantaneous bandwidth, increased dynamic range and with a two-order-of-magnitude decrease in size and weight. Moreover, because of the elimination of all of the I/O drivers and attendant circuitry, power consumption is reduced by two-thirds, whereas the mean time before failure is increased to 10,000 hours due to the robustness of the monolithic integrated circuit and use of fiber optics.

Abstract: What is provided is a receiver-on-a-chip comprising a monolithic integrated circuit that reduces the receiver to a cigarette-pack-sized assembly mountable directly at an antenna element, with a much-increased operational bandwidth and instantaneous bandwidth, increased dynamic range and with a two-order-of-magnitude decrease in size and weight. Moreover, because of the elimination of all of the I/O drivers and attendant circuitry, power consumption is reduced by two-thirds, whereas the mean time before failure is increased to 10,000 hours due to the robustness of the monolithic integrated circuit and use of fiber optics.

Abstract: The present invention is directed to a system and method for the identification of a target object in PCL radar applications. The disclosed embodiments describe the systems and methods used in the identification of a target object from the collection of data representing specific target object features, such as velocity, altitude, fuselage length, wing length, or wing sweepback angle, and the comparison of selected target object features with a database of known aircraft features. The present invention also provides for the calculation of feature dimensions, such as the fuselage length, wing length, or wing sweepback angle from measurements associated with a peak signal lobe as a function of a bistatic aspect angle.

Abstract: A radio-frequency tag communication system including (a) a radio-frequency tag, (b) a radio-frequency tag communication device configured to transmit a transmitted signal toward the radio-frequency tag, and to receive a reply signal transmitted from the radio-frequency tag in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag, and (c) at least one reference tag disposed fixedly in an area of communication of the radio-frequency tag communication system and configured to transmit a reply signal in response to the transmitted signal, for thereby effecting radio communication with the radio-frequency tag communication device, and wherein the radio-frequency tag communication device includes a directivity control portion configured to control a directivity of communication with the radio-frequency tag, on the basis of a result of the radio communication of the radio-frequency tag communication device with the at least one reference tag.

Abstract: A height-finding 3D avian radar comprises an azimuthally scanning radar system with means of varying the elevation pointing angle of the antenna. The elevation angle can be varied by employing either an antenna with multiple beams, or an elevation scanner, or two radars pointed at different elevations. Heights of birds are determined by analyzing the received echo returns from detected bird targets illuminated with the different elevation pointing angles.

Abstract: One embodiment relates to a dual mode radar transceiver. The dual mode transceiver includes a plurality of transmit channels. Each of the plurality of transmit channels is adapted to switch between a first mode and a second mode. The first mode includes a first combination of the plurality of transmit channels adapted to concurrently transmit outgoing signals. The second mode includes a plurality of different combinations of the plurality of transmit channels. Each of the plurality of different combinations has fewer transmit channels than the first combination. Other methods and systems are also disclosed.

Abstract: A proposed spread spectrum signal receiver includes a radio front-end unit and a processing unit. The radio front-end unit, in turn, has an antenna, a digitizing circuit and a primary buffer unit. The antenna is adapted to receive radio signals (SHF) from a plurality of signal sources, and the digitizing circuit is adapted to downconvert and filter the received signals (SHF), and generate sample values (SBP-D) thereof. The primary buffer unit is adapted to temporarily store the sample values (SBP-D) from the digitizing circuit and allow the processing unit to read out a first set of stored sample values (SBP-D) contemporaneously with the storing of a second set of sample values (SBP-D) in the primary buffer unit. The processing unit is adapted to receive the sample values (SBP-D) from the primary buffer unit, and based thereon, produce position/time related data (DPT).

Abstract: A surface acoustic wave (SAW) expander based transmitter and correlator based receiver comprises SAW devices that perform expander or correlator functions based on the types of signals inputted to the SAW devices. The SAW devices incorporate chirp with adaptive interference and programmable coding capabilities. The SAW devices and method of operating the devices allow the implementation of very low power radios that overcome problems with temperature drift, lithography constraints and interference and jamming suffered by prior art implementations.

Abstract: A shared satellite gateway can be configured to process at least first and second communications signals associated with respective at least first and second space-based components. The at least first and second communications signals are provided to/from the shared satellite gateway by respective at least first and second service links and respective at least first and second feeder links of the respective at least first and second space-based components.

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: 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: The invention provides an adaptive frequency hopping spread-spectrum (FHSS) transmission system and method, which efficiently utilizes available transmission bandwidth, whilst providing robustness to jamming techniques in wireless communication systems. The proposed technique operates by transmitting a wide-band signal over multiple, single-carrier, parallel transmission subbands, which may occupy non-contiguous frequency regions. The proposed scheme exhibits significant gain in error rate performance, as compared to a data rate equivalent single-subband system in the presence of signal jamming and/or interference without a reduction in the transmission data rate nor an increase in transmitter power. In addition, the proposed system and method are adaptive and enable more efficient use of the available bandwidth for communicating, thus increasing the overall bandwidth utilization of the system.

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: What is provided is a receiver-on-a-chip comprising a monolithic integrated circuit that reduces the receiver to a cigarette-pack-sized assembly mountable directly at an antenna element, with a much-increased operational bandwidth and instantaneous bandwidth, increased dynamic range and with a two-order-of-magnitude decrease in size and weight. Moreover, because of the elimination of all of the I/O drivers and attendant circuitry, power consumption is reduced by two-thirds, whereas the mean time before failure is increased to 10,000 hours due to the robustness of the monolithic integrated circuit and use of fiber optics.

Abstract: A radio communication apparatus includes a received beam generating section 12 for generating received beams beam0 and beam1, which are perpendicular to each other and spatially separated, by assigning weights to received signals fed from receiving antennas 11 by using received beam weights; path search sections 13 and 14 each for outputting path information when the received beams beam0 or beam1 includes a spread signal spread by a known spreading code; a demodulating section 16 for outputting demodulation data by receiving the received beams beam0 and beam1 and by RAKE combining them in response to the path information; and a feedback control section 15 for outputting selection information 101 by selecting a transmission beam to be transmitted in response to the path information and the phase difference between the received beams beam0 and beam1 fed from the demodulating section 16.

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 for generating a multiresolution decomposition of an array signal by a bank of spatial bandpass filters is disclosed. The signal processing operation is implemented through the use of the directivities of the individual array elements and does not degrade the spatial or temporal resolution of the array.

Abstract: A communication system has a high altitude communication device that has an antenna for directing beams to a fixed cell pattern with a polarity of cells. A specific pattern of cells having the same communication resource is provided. Preferably, cells having the same resource are separated. The antenna is shaped to suppress interference with locations having the same resource. The areas not having the same resource are not suppressed to allow the system to have maximum capacity and allow a smaller antenna aperture.

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 weather radar antenna for radiating a desired beam formed by feeding quadrants of the antenna uses a dual-mode switched aperture antenna feed. The dual-mode switched antenna feed has an input divider that splits the input signal. A left switch switches the split input signal using a left first diode and a left second diode to top left and bottom right quadrants of the antenna. A right switch switches the split input signal using a right first diode and a right second diode to top right and bottom left quadrants of the antenna. The diodes are forward and reverse biased as required to feed top, bottom, left and right portions of the antenna to obtain the desired beam. When all the diodes are reversed biased the split signal is fed to all quadrants of the antenna.

Abstract: A radar apparatus is provided that can correctly extract the necessary point for a determination related to the safe travel of one's automotive vehicle among objects such as automotive vehicles moving at an angle in front and constructed objects. The radar apparatus of the present invention provides antennas that transmit beams in a plurality of directions and receive the reflected waves from objects as received signals. The objects that generated these reflected waves are detected.

Abstract: A slow speed pulse chase apparatus in a bistatic radar system, wherein the receive antenna follows the transmit pulse out in space. The receive beam comprises many parallel beams that overlap all the possible positions of the transmit pulse as it travels into space. Slow speed chase apparatus provides a small group of beams which are held in a fixed location as the transmit pulse travels by and then is jumped in one large step to continue to the next position to remain there until the transmit pulse travels by.

Abstract: Where two or more antenna beams may receive signals from the same cellular communication system user, post-reception beam channel gain variations may obscure choice of the channel providing the strongest user signal. Thermal atmospheric noise, assumed to equally enter each beam, is utilized as a standard signal level in order to calibrate the relative gain factor for each channel. Thermal noise level is measured by use of a single common receiver (32) sequentially coupled to each channel (22-25) to listen for lowest signal levels during inactive intervals, over periods of time which may extend for hours. Lowest signal levels provide thresholds for each channel from which gain correction factors are developed. When a user signal is received in two channels, the gain correction factors are employed to select the channel providing the best signal, on a substantially real time basis. A long-term lowest signal level monitoring algorithm is described.

Abstract: A radar system and method for use in collision avoidance systems. A radar system in accordance with the present invention may comprise a plurality of antennas, an RF power generator, a transmitting unit, a receiving unit, and a direction detector. Each of the antennas is arranged to radiate a beam having substantially the same pattern as the beams radiated by the other antennas. The beam of each antenna is radiated in a slightly different direction from the beams radiated by the other antennas. Each antenna is also arranged to receive return beams, wherein each of the return beams comprises a beam radiated from one of the beam radiating means and reflected by an object. The RF power generator generates RF power of nearly constant amplitude. The transmitting unit distributes the RF power to each of the antennas, and the RF power is radiated successively. The receiving unit generates amplitude detecting signals which are used to detect the amplitudes of the return beams received by the antennas.

Abstract: A fine tracking radio frequency sensor system capable of locating ground beacons within an angular field which is substantially larger than -3dB antennae beamwidth beams, to be used preferably on board artificial telecommunication satellites equipped with single or multiple beam antennae.

Abstract: A dual stacked beam radar in which, after listening to low stack beams, and waiting for their echoes to return, a transmitter signal is transmitted on high, the high stack beams being listened to during the longer dead times during variable interpulse periods of the low stack beams.

Abstract: In a tracking system for a stationary satellite, a phased array is used for an antenna mounted on an automobile. The phased array antenna has a sharp beam which is switched between two different directions in azimuth. The antenna beam is switched between the two directions periodically by control of phase constants in a feeding circuit of the antenna and comparison is made in strength between signals received before and after the beam switching to obtain an error signal as an azimuth error signal. Then, the antenna is mechanically moved in azimuth according to the azimuth error signal until the azimuth error signal becomes zero. In a case the antenna beam is also switched between two directions in elevation, the antenna beam is switched in elevation during an interval between successive two times of the beam switching operation in azimuth and detects a difference in strength of signals received before and after the switching in elevation to thereby produce the difference as an elevation error signal.

Abstract: A radar device radiates and receives radio frequency energy pulses using an antenna having two independently driven major lobes. The two major lobes aim in two separate directions, and a third direction halfway between the two directions exhibited by the two major lobes represents an aim line of the apparatus. The antenna selectively radiates both circularly and linearly polarized pulses. Reflections received from circularly and linearly polarized pulses are compared to prevent a false indication of an object's centroid.

Abstract: A mono-lobe tracker is described for tracking a target emitting radio signals incorporating an antenna, a circuit for sequential lobing, a radio frequency amplifier, a mixer, an intermediate frequency amplifier, an amplitude modulator detector, and integrators for storing the amplitude signals corresponding to predetermined off boresight positions, means for taking the difference of two integrators indicating the boresight error, a motor coupled to the error signal for driving the antenna in response to the error signal and a random number generator for generating at random a plurality of frequencies which are coupled as randomly selected to the sequential lobing circuit. A random number generator is also described incorporating a noise diode, an amplifier, a voltage comparator and a counter.

Abstract: A frequency agile radar system allows tracking of noncooperative targets with high accuracy. The system is particularly useful in an automatic landing system aboard an aircraft carrier. The radar employs an electronically steered planar array antenna system in which a symmetrical pencil beam of 1.degree. beamwidth is steered in 1/2.degree. steps in a raster scan. A space-stabilized acquisition window allows target acquisition, and target scanning modes are chosen as a function of target range. At far range, target scan is effected by those four beam raster positions which bracket the target whereas when the target is at near range where its cross section is larger than a single beamwidth, the raster is "ballooned" to paint or cover the target fully. The computed track of the target provides a continuing update of autopilot command signals radioed to the target to bring it to and hold it on a selected glideslope which effects the automatic landing.

Abstract: Discrimination between sidelobe and main beam reception of interference signals in a lobe on receive only radar is accomplished by a method of operation in which interference signals are stored and averaged for the radar receive beam positions of boresight, up, down, left and right. Interference signals received at boresight are compared with interference signals received at each off-boresight beam position. Interference signals received at boresight are also differenced with interference signals received at the off-boresight beam positions and the results are compared with beam width defining threshold factors. The determined values are applied to logic functions that indicate reception of interference signals outside of the main beam pattern.