208 results about "Reference antenna" patented technology

The invention relates to a navigation system receiver comprising at least two antennas, one of which is a "reference" antenna. A multiplexer multiplexes the signals from the antennas, and a first processor situated downstream from the multiplexer delivers at least one navigation parameter on the basis of the signals from the multiplexer. The receiver includes a second processor having an input receiving in continuous manner signals from the reference antenna to deliver at least one reference signal representative of a position parameter of the reference antenna. Processor means process the signals from the multiplexer while taking account of at least one said reference signal.

A carrier phase-based relative positioning apparatus comprises a plurality of antennas of which at least one is installed on a mobile unit. The apparatus determines the position of each antenna other than one antenna used as a reference antenna relative to the reference antenna by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase. The apparatus judges that the integer ambiguity has been incorrectly determined if the position of any of the antennas relative to the reference antenna (or the angle of a flat plane formed by those two antennas) falls out of a preset range in which the relative position (the angle of the flat plane) falls under normal conditions.

Beamforming methods and systems are described in which differential channel estimation can be computed based on measured power at receiver. Simultaneous activation of antennas in separate pairs can be used to determine relative phases of antennas with respect to a reference antenna based on the power measurements. In turn, the beam forming signals can be weighted in accordance with the relative phases to adapt the signals to a multipath environment. Existing power measurement capabilities of conventional receivers can be employed to achieve approximate channel estimates.

Provided is a mobile cellular communication system or, more particularly, a transmission diversity communication system in which when the number of transmitting antennas is increased, antennas can be calibrated readily and efficiently with power saved without degradation of the characteristic concerning fading. The transmission diversity communication system is a closed-loop transmission diversity communication system. In the transmission diversity communication system, a base station transmits common pilot signals via a plurality of antennas, and a mobile station receives the common pilot signals. The mobile station transmits feedback signals, which are produced through analysis of the common pilot signals, to the base station. The base station controls a downward transmission signal on the basis of the pieces of feedback information. Herein, the plurality of antennas is divided into a plurality of groups. The common pilot signal is transmitted via a reference antenna included in each of the groups. The common pilot signal is alternately transmitted at a low frequency via the other antennas.

The invention relates to a benchmark testing system and a method for RFID label operating level. The benchmark testing system comprises a support for labels to be tested, a transceiver and reference antenna support, wherein a transceiver and reference antenna is placed in a standard testing environment. A circulator, a spectrum analyzer, an RFID signal generator and a power meter are placed outside the standard testing environment. The method is that an RFID label chip and the antenna are viewed as a whole body, the input level and the output level of an RFID label system are measured throughthe transceiver and reference antenna by adopting the transmission formula of electromagnetic waves in a free space, the minimum level capable of activating the operation of an RFID label is calculated and the theoretical reading distance of the RFID label is estimated. Through the scientific, repetitive and comparable non-contact measurement of the RFID label power consumption which is one of important indicators determining the performance of the RFID label, the problems that the existing technical indicators are ambiguous and the error of the testing results is great, and assistant decision basis is provided for users to select RFID label products according to the different application requirements.

A positioning system for radio frequency devices includes a two-way radio antenna, for vehicles, having a transmitting and a receiving element. Reference antennas have retro-directive arrays which can shape the signal beams in elevation; polarize transmission and reception signals according to a circular or a linear polarization, the polarized transmission retro-directively reflecting signals having the same polarization as the incident ones in the case of circular polarisation, or retro-directively reflecting signals having orthogonal polarisation in the case of linear polarisation. An encoder is included for transmitting an identification code of the reference antenna. A controller processes the spatial and temporal data resulting from communication through the radio waves transmitted and received by the vehicle antennas and reflected by the reference antennas. The controller calculates the distance of the vehicle from the reference antennas that have reflected the signal transmitted by the antennas.

The invention relates to a transceiver antenna calibration error-based multipoint coordinated robust pre-coding method, which belongs to the field of wireless communication technology, and comprises the following steps that: a coordinated base station obtains the statistical characteristics of a downlink channel between the coordinated base station and the served user according to the coordinated base station, a relationship between the uplink / downlink channels of the served user and the uplink channel, calculates the pre-coding vectors of all served users according to the statistical characteristics of the downlink channel, constructs an initial pre-coding matrix so as to obtain a final pre-coding matrix, and maps the original signals sent to all served users as transmitted signals according to the final pre-coding matrix. The method has the advantages of recovering the loss in system performance resulting from unsatisfactory antenna calibration, effectively reducing the system cost by reducing the requirement on calibration precision, and providing high system performance.

The invention discloses a method and a device for calibrating antennae, which are used for calibrating n antennae, wherein n is more than or equal to 2. The method comprises the following steps: selecting the ith antenna from the n antennae as a reference antenna, and determining the calibration coefficient of the reference antenna as a preset value; sending the same calibrating signals between the ith antenna and the rest antennae, and determining the calibration coefficients of the rest antennae according to the received values of the calibration signals; and using the calibration coefficients to calibrate antenna signals. The method and the device need no calibration networks, in short, connections are unnecessary to be established between the antennae, namely a unified calibration portis not needed for receiving and sending the calibration signals, thereby avoiding the problems that the prior scheme has high cost and large implementation difficulties caused by the calibration networks.

The invention discloses an antenna phase center calibration system based on site insertion loss measurement, which comprises an open site, a reference antenna, an antenna phase center calibration processor, a GPIB (General Purpose Interface Bus) card, a vector network analyzer and an antenna lifting component. When a to-be-measured antenna is subjected to phase center calibration, site insertion loss between the to-be-measured antenna and the reference antenna under the antenna heights is used twice, and an offset of an antenna phase center of the to-be-measured antenna relative to a reference point is acquired by a reflection wave path-reflection coefficient invariant strategy and an antenna phase center mean convergence criterion. The system aims at providing a calibration method for an open site antenna phase center. According to the system and the method, the antenna with the precise and known antenna phase center serves as the reference antenna, so that phase center calibration of the to-be-measured antenna is achieved; a phase center calibration mode depending on the reference antenna facilitates quantity value transmission of an antenna phase center parameter; and quantity value unification of the antenna parameter is achieved.

The invention discloses an antenna calibrating method and an antenna calibrating device used in a time division duplex coordinated multiple point system. The antenna calibrating method comprises a step of calibrating antennas among cells by a network side: selecting a standard antenna, taking the standard antenna as the standard, and calibrating reference antennas in all the cells; and a step of calibrating the antennas in the cells by the network side again: taking the reference antenna of the cell as the standard in each cell, and calibrating other antennas in the cell, excepting the reference antenna, wherein one of the antennas of the cell is selected as the reference antenna of the cell in each cell respectively. By using the protocol of calibrating the antennas among the cells firstly and then calibrating antennas in the cell on the basis of calibration among the cells, the reciprocity of an uplink and a downlink in the calibrated cell cannot be damaged; the channel reciprocity performance of the time division duplex (TDD) coordinated multiple point (CoMP) system is improved, so that the transmission performance of the CoMP system is also improved.

Provided are an apparatus for correcting a phase of a phased array antenna and a method thereof. The apparatus for correcting a phase of a phased array antenna for receiving a radio signal, includes a phased array antenna for receiving radio signals from a reference antenna and combining power of the received radio signals, a power dividing unit for dividing the combined power of the received radio signals, a voltage detecting unit for detecting voltage values of the divided radio signals, and a phase controlling unit for estimating a phase error that makes the detected voltage value maximum and controlling a phase of each radiation element of the phased array antenna using the estimated phase error.

In an apparatus for measuring a specific absorption rate (SAR), a first near magnetic field distribution of a radio wave radiated from an array antenna of a reference antenna including a plurality of minute antennas is measured, and an SAR distribution with respect to the radio wave radiated from the array antenna is measured with a predetermined phantom. Then a distribution of a transformation coefficient α is calculated by dividing the measured SAR distribution by a square of the measured first near magnetic field distribution, a second near magnetic field distribution of a radio wave radiated from a measured radio communication apparatus is measured, and an SAR distribution with respect to the radio wave radiated from the radio communication apparatus is calculated by multiplying a square of the measured second near magnetic field distribution by the calculated distribution of the transformation coefficient α.

The invention discloses a single channel dual base station ultra-short wave signal spatial positioning method and belongs to the technical field of ultra-short wave radio position finding. According to the method, a dual base station positioning system is constituted of a single channel Doppler antenna array and a reference antenna; phase positions are extracted directly from simulation signals to act as data base; two-dimensional information of azimuth angle and pitch angle is converted to one-dimensional information by use of space included angles, match searching is performed to data base and measured phase positions by use of a similarity measurement function to obtain azimuth angle of a target source. By use of the method, aerial ultra-short wave radio-frequency signals can be accurately positioned, the real-time performance of a direction-finding system is increased, system cost and complexity are reduced, and labor and economic investment are saved; the method is of great practical importance.

The invention relates to a millimeter-wave\submillimeter-wave near-field amplitude and phase measuring method, and the base technical principle of the method is as follows: a same source-excited signal is distributed in a to-be-measured antenna and a reference antenna by a directional coupler and sent out, the spatial interference fields of the two in a scanning area are received by a scanning probe, and the amplitudes of the spatial interference fields are measured by a measuring system. Through carrying out virtual signal processing on the amplitudes of the spatial interference fields, the near-field amplitude and phase of the to-be-measured antenna are calculated and reconstructed, and if necessary, a far-field directional diagram can be obtained through far and near field transformation processing.

A radio measurement apparatus comprising: an array antennal selection unit selecting array antennas corresponding to received signals; a reference path selection unit selecting a reference array antenna; a signal processing unit selecting a reference antenna channel through analysis of signal characteristics measured through two reception channels; a sequential channel multiplex unit determining sequentially inputting received signals of remaining array antennas to output the sequentially input signals to a receiver; and a correction signal input unit compensating amplitude and phase characteristics of the respective reception channels.

The invention discloses an antenna calibration method based on time division duplex (TDD) coordinated multi-point transmission, comprising: during the TDD coordinated multi-point transmission process, the base station to which a cell belongs determines that multiple antennas of the cell need to be calibrated, then The base station selects a reference antenna from multiple antennas in the cell; the base station adjusts the gain and / or phase of the radio frequency link corresponding to the antenna according to the gain and / or phase of the radio frequency link corresponding to the reference antenna Adjustment is performed, and the antenna to be adjusted is one or more of the other antennas in the cell antenna except the reference antenna. The present invention also correspondingly discloses an antenna correction system based on TDD multi-point coordinated transmission. The present invention corrects multiple antennas in the same cooperative cell by selecting a reference antenna, so that the uplink and downlink signal channels maintain reciprocity, Therefore, the validity of the SRS feedback can be guaranteed, the accuracy of the feedback can be improved, and additional resources can be saved.

A phase array antenna includes an oscillator, a plurality of antenna elements, a phase shifter, a distributor, a receiving unit, and a control processor. The control processor performs a calibration process to select, from the antenna elements, a reference and target antenna elements to allow the radio waves generated by the oscillator to be provided for the reference and target antenna elements via the distributer, obtain a pattern of a change in a received power of radio waves received at the receiving unit, when a phase of the phase shifter for the reference antenna element is fixed and a phase of the phase shifter for the target antenna element is changed, extract, from the pattern obtained, the phase of the phase shifter for the target antenna element at which the received power becomes a local minimal value, and add the phase extracted to 180° to set its resultant value to a calibration value for the phase of the phase shifter for the target antenna element.

A positioning system for radio frequency devices includes a two-way radio antenna, for vehicles, having a transmitting and a receiving element. Reference antennas have retro-directive arrays which can shape the signal beams in elevation; polarize transmission and reception signals according to a circular or a linear polarization, the polarized transmission retro-directively reflecting signals having the same polarization as the incident ones in the case of circular polarization, or retro-directively reflecting signals having orthogonal polarization in the case of linear polarization. An encoder is included for transmitting an identification code of the reference antenna. A controller processes the spatial and temporal data resulting from communication through the radio waves transmitted and received by the vehicle antennas and reflected by the reference antennas. The controller calculates the distance of the vehicle from the reference antennas that have reflected the signal transmitted by the antennas.

The antenna testing process includes the following steps: 1) selecting one network analyzer with the first port and the second port, one reference antenna, one non-metal box and one antenna to be tested; 2) setting on the non-metal box the first holding part and the second holding part; 3) setting the reference antennan and the tested antenna separately inside the first holding part and the second holding part; 4) connecting the reference antennan and the tested antenna separately to the first port and the second port of the network analyzer; and 5) transmitting reference signal via the first port to the reference antenna for emitting outwards, receiving the signal with the tested antennan and transmitting the signal to the second port, and obtaining the measurement result of the tested antennan in the network analyzer. The present invention has high antenna testing quality and efficiency.

A carrier phase-based relative positioning apparatus comprises a plurality of antennas of which at least one is installed on a mobile unit. The apparatus determines the position of each antenna other than one antenna used as a reference antenna relative to the reference antenna by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase. The apparatus judges that the integer ambiguity has been incorrectly determined if the position of any of the antennas relative to the reference antenna (or the angle of a flat plane formed by those two antennas) falls out of a preset range in which the relative position (the angle of the flat plane) falls under normal conditions.

Provided is a system and method for measuring an antenna radiation pattern in a Fresnel region based on a phi-variation method. The system includes a rotator for changing angles of a reference antenna and a target antenna; a vector network analyzer for obtaining radiation pattern data in accordance with transmission / reception radio frequency (RF) signals between the reference antenna and the target antenna; a measurement unit for calculating a far-field radiation pattern based on the radiation pattern data received from the vector network analyzer; and a controller for controlling the rotator according to a measurement angle transmitted from the measurement unit.

In a passive radar system a space-borne transmitter broadcasts wide-band digitally modulated signals over a region and illuminates the region. A receiver antenna is oriented to receive radiation from at least one portion of the region. The portion is an area viewed by the receiver antenna. A reference antenna is oriented toward the transmitter, the reference antenna receives a portion of the wide-band digitally modulated signal. A coherent processing time duration is selected based on: a radar cross-section of a target within the viewed area, a bandwidth of the wide-band digitally modulated signal, and the viewing angle of the receiver antenna. The received signal from the receiver antenna is coherently processed with a reference signal from the reference antenna, over a time interval greater than the coherent processing time duration.

The invention belongs to the radar technology field and discloses an outer radiation source radar cofrequency interference elimination method. The method comprises steps that a reference signal received by a reference antenna and M echo signals received by an array element antenna are acquired; direct wave signals and multi-path signals of the M echo signals are eliminated by utilizing the reference signal to acquire M first echo signals, and an echo signal matrix is constructed; independent component analysis on the echo signal matrix is carried out to acquire three independent component signals; the three independent component signals are utilized to carry out three times of time domain interference elimination for the echo signal matrix to acquire three second echo signals; distance-Doppler two-dimensional correlation for each second echo signal and the reference signal is carried out to acquire three correlation matrixes, target detection is carried out by utilizing the correlation matrixes, second echo signals corresponding to the correlation matrixes of the target information can be acquired, namely echo signals after cofrequency interference elimination. The method is advantaged in that cofrequency interference in a main lobe can be effectively eliminated, and a relatively good target detection result is acquired.

In one embodiment, a RF sensor comprising a sensing antenna and a reference antenna, wherein a sensing material is disposed upon said sensing antenna and wherein the sensing antenna is configured to test for specific analyte by measurement of the resonant impedance spectra, and the reference antenna is configured to mitigate and correct for environmental parameters and positionn. In a further embodiment, a method for sensing comprising; utilizing an RF sensor, wherein the RF sensor comprises a sensing antenna and a reference antenna, wherein said RF sensor is configured to test for a specific analyte; and, measuring a resonant impedance spectra of the sensing antenna and reference antennaat multiple frequencies to provide a subsequent multivariate analysis of a signal response from the RF sensor.

The invention discloses a method for calibrating a reference antenna between two base stations in a CoMP (Coordinated Multi-Point) system, a device for implementing the method and a base station comprising the calibrating device. The method comprises the following steps: determining a coordinated calibration node in a network; acquiring an average SINR (signal-to-interference-and-noise-ratio) by a base station to be calibrated and the coordinated calibration node; feeding average channel quality information back to a home base station by the coordinated calibration node; selecting a calibration path between two base stations by a centre scheduler; on the calibration path, choosing a node as an initial node of calibration and starting to calibrating an antenna selected by two neighboring nodes on the calibration path. By adopting the method provided by the invention, the reference antenna between two base stations can be calibrated by utilizing an air interface to feed back less information, and calibration between base stations can be better realized.

The invention discloses an antenna radiation pattern reconstructible method, an antenna device and wireless communication equipment. The method comprises the steps of selecting one antenna as a reference antenna, and arranging a second antenna at a position which is separated from the reference antenna by a distance of lambda / 8; determining strength arrangement of an electromagnetic signal in a space; and adjusting a phase difference between the second antenna and the reference antenna so that a maximal radiation direction of an antenna system which is formed by the second antenna and the reference antenna is aligned to or next to a direction with highest electromagnetic strength in the space. According to the antenna radiation pattern reconstructible method, the antenna device and the wireless communication equipment, through arranging a plurality of antennae in the wireless communication equipment, the phase difference among the plurality of antennae is automatically adjusted according to change of a communication environment in which the wireless communication equipment exists, thereby realizing intelligent switching of the radiation pattern of the antenna device from omnidirectional to directional; through adjusting the maximal radiation direction of the antenna radiation pattern for being aligned to or next to the direction with best communication signal in the communication environment, optimal signal exchange between sets of equipment can be realized, and furthermore communication performance of the wireless communication equipment is remarkably improved.

A phased array antenna includes an oscillator, a plurality of antenna elements, a phase shifter, a distributor, a receiver, and a control processor. The control processor performs a first calibration process to calibrate a phase of the phase shifter connected to a pair of antenna elements that is selected from the antenna elements and are located at a pair of positions symmetric with respect to a central axis of an array formed by the phased array antenna, and a second calibration process to calibrate a phase of the phase shifter connected to a pair of target antenna elements with respect to a phase of the phase shifter connected to a reference antenna elements located at a central portion of the array. The pair of target antenna elements are located at a pair of positions that are symmetric with respect to the central axis of the array.