222 results about "Antenna polarization" patented technology

A radio-over-fiber (RoF) optical fiber cable system with transponder diversity for a RoF wireless picocellular system that includes at least one optical fiber cable. The at least one optical fiber cable supports one or more groups of two or more transponders, wherein the transponders in a given group are arranged to form substantially co-located picocells. The transponders in each transponder group may also have one of two orthogonal antenna polarizations. A diversity combiner optically coupled to each transponder determines respective signal strengths from each transponder in each transponder group. The transponder with the greatest signal strength in a given transponder group is selected to form the picocell for the given group. This allows for the optical fiber cable system to adjust to changes in the signal strength of each picocell, such as caused by a transponder obstruction or failure.

In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously. Furthermore, the antenna polarization may be static or dynamically controlled at the subarray or radiating element level.

The invention discloses an automatic measuring system in the center of an antenna phase, which comprises an antenna receiving rotary table subsystem, an emission polarizer subsystem, an emission and reception subsystem, a servo drive digital display subsystem and a computer subsystem. The antenna receiving rotary table subsystem and the emission polarizer subsystem are both connected with the emission and reception subsystem, the servo drive digital display subsystem and the computer subsystem; wherein, the antenna receiving rotary table subsystem consists of a direction rotary table (1), a two-dimensional translation device (2), a bracket (3) and an antenna polarizer (4). The two-dimensional translation device (2) is positioned between the direction rotary table (1) and the antenna polarizer (4) and used for automatically adjusting the positions of an antenna and the rotating axis of the direction rotary table, thereby making the phase center of the antenna near the axle center of the rotary table and ensuring the stable positions of the rotating axis of the direction rotary table and the rotating axis of the antenna polarizer when the direction rotary table is rotating. The automatic measuring system provided by the invention has the advantage of high measuring automation and can be used to accurately mark the phase centers of antennas.

The present invention includes a wireless communication system. The wireless communication system includes a plurality of transceiver antennae. Each transceiver is spatially separate from at least one other transceiver antenna. Each transceiver antenna includes a transceiver antenna polarization. At least one transceiver antenna has a polarization that is different than at least one other transceiver antenna. Each transceiver antenna transmits a corresponding data stream. The wireless communication system further includes a plurality of receiver antennae. The receiver antennae receive at least one data stream. The transceiver antenna polarization of each transceiver antenna is pre-set to optimize separability of the received data streams. A transmission channel between the transceiver antennae and the receiver antennae can be estimated with a channel matrix. The pre-set transceiver antenna polarization of each transceiver antenna can be determined by minimizing a singular value spread of the channel matrix. A pre-set receiver antenna polarization of each receiver antenna can also be determined by minimizing a singular value spread of the channel matrix.

A networked radio frequency identification system includes a plurality of radio frequency identification (RFID) tag readers, a computer in signal communication with the RFID tag readers over a network, and a software module for storage on and operable by the computer that localizes RFID tags based on information received from the RFID tag readers using a network model having endpoints and oriented links. In an additional example, at least one of the RFID tag readers includes an adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation. In a further aspect, the system localizes RFID tags based on hierarchical threshold limit calculations. In an additional aspect, the system controls a locking device associated with an access point based on localization of an authorized RFID tag at the access point and reception of additional authorizing information from an input device.

The invention discloses an automatic compensation system and a compensation method of gesture of a portable satellite antenna. The system comprises an antenna controller used for calculating theoretical azimuth angle, pitch angle and polarizing angle of the antenna and controlling other devices to work, a polarization transmission device used for driving the antenna to rotate in polarization mode, a polarization potentiometer used for feeding back polarization sampling, an azimuth transmission device used for driving the antenna to rotate in azimuth mode, a pitch transmission device used for driving antenna to rotate in pitching mode, a tilt angle sensor used for measuring tilt angle parameter of the antenna in real time and feeding the parameter back to the antenna controller and a global position system (GPS) used for providing satellite tracking parameter. By means of the system and the method, the pitching angle of the antenna keeps actual working direction all the time in the star finding process, polarization errors caused by terrain shapes are compensated in real time, antenna star finding speed and polarization adjustment accuracy are greatly improved, and interference to satellite communication caused by polarization errors is reduced.

A wireless communication device and a wireless communication method. The wireless communication device participates in wireless communication involving an antenna array, includes: a communication unit, configured to receive a signal including antenna array geometric information about a target communication device from the target communication device of the wireless communication device; and an antenna array geometric information parsing unit, configured to determine an antenna array geometric configuration of the target communication device according to the signal, wherein the antenna array geometric information indicates at least one of a geometric arrangement way of antenna elements in the antenna array, an antenna element interval and an antenna polarization direction.

The invention relates to a phased array radar transmitting channel far-field calibration method and system. Two antennas are erected in a far field, the polarization manners of the two antennas are vertical to each other, an auxiliary antenna is mounted beside a radar array surface, the polarization manner of the auxiliary antenna is vertical to the radar array surface, and the auxiliary antenna is used for receiving signals transmitted by the second antenna in the far field. A radar signal processing machine performs phase testing on a signal transmitted by an auxiliary receiving channel, the phase of the signal transmitted by the auxiliary receiving channel is regarded as a transmitting reference phase, the phase of each channel transmitting signal of the radar array surface is compared with the transmitting reference phase, the required phase correction is acquired by subtraction, the phase shifter of a transmitting component is controlled to perform shifting according to the obtained phase correction, and transmitting channel far-field calibration is achieved. Compared with traditional methods, the calibration method and system has the advantages that signal measuring equipment such as a spectrometer and an oscilloscope which are erected at a far end is omitted, and reference clock transmitting to the far end is omitted.

The invention provides an on-chip antenna test device. An adjusting mechanism is arranged on a probe bench pedestal and is formed by X, Y, and Z mobile platforms. Antennas on an antenna chip-bearing bench are precisely positioned via a CCD telescope and the adjusting mechanism. A probe support performs feeding for the on-chip antennas. Via the rotation of a low-position axis and a polarization axis, matching for polarization of a receiving antenna and an emission antenna is performed. If the polarization of the receiving and emission antennas is matched, full-directional data acquisition in 0-360 DEG is performed via a rotation shaft. In the low-direction axis, a direct-current servo motor drives a synchronous tooth belt wheel which drives a turbine worm. The turbine worm drives a straight gear which drives a sliding guide rail. According to the invention, a feeding problem of the antennas is solved; the test device is provided with front and back testing ability of the antenna; effects of interference on antennas of a traditional bench body are reduced; and testing functions of holographic stereoscopic directional diagram of a to-be-tested antenna is achieved.

The invention discloses a broadband multi-polarized reconfigurable slot antenna and a polarization method therefor. The broadband multi-polarized reconfigurable slot antenna comprises four layers of dielectric substrates, wherein an elliptical metal patch is arranged on the lower surface of the first layer of dielectric substrate; a first feed structure is arranged on the upper surface of the second layer of dielectric substrate; a metal layer is arranged on the upper surface of the third layer of dielectric substrate; a quasi-cross-shaped slot is formed in the metal layer; a second feed structure is arranged on the upper surface of the fourth layer of dielectric substrate; and a reconfigurable wilkinson power divider is arranged on the lower surface of the fourth layer of dielectric substrate. The linear polarization radiation state with ultrahigh port isolation in two vertical directions can be achieved through a quasi-cross-shaped slot antenna fed through the first feed structure and the second feed structure; the wilkinson power divider conducts different paths through pin diodes and is connected with the first feed structure and the second feed structure through a plated through hole, so that five different antenna polarization modes of -45-degree linear polarization, 45-degree linear polarization, +/-45-degree dual-linear polarization, left-hand circular polarization andright-hand circular polarization can be achieved, the relative bandwidth is close to 20%, and the broadband multi-polarized reconfigurable slot antenna fully adapts to different work requirements.

The invention provides a polarization reconfigurable high-gain panel antenna. 21dBi gain can be achieved and aperture efficiency can achieve 70% by only one feed antenna; and furthermore, by switching control, the polarization state of the antenna can be converted between left-hand circular polarization and right-hand circular polarization, a complex feed network and a control circuit are eliminated, and the polarization reconfigurable high-gain panel antenna has the advantages of simple feed, low loss, high efficiency, easiness in control and high polarization purity.

Systems and techniques for reading radio frequency identification (RFID) tags and determining the distance between a reader and a tag being read. A plurality of interrogation signals are transmitted to an RFID tag, with signals at a first frequency being transmitted at a plurality of antenna polarizations and signals at a second frequency being transmitted at a plurality of antenna polarizations. The antenna polarizations are chosen such that return signals resulting from the signals and traveling along reflective paths will sum to zero. Return signals received from the tag are averaged, and phase shift information exhibited by the return signals is determined. The phase shift information for the return signals and frequency information for the interrogation signals is used to compute the distance between the reader and the tag.

The invention provides a POLSAR image unsupervised classification method based on target scattering identification. The POLSAR image unsupervised classification method comprises the steps of: 1, calculating a POLSAR image polarization scattering entropy and similarity parameters of surface scattering, even time scattering and volume scattering and initially dividing classes of POLSAR images by using the parameters; 2, selecting the minimum antenna receiving power characteristic polarization of surface features mainly referring to surface scattering, and with the minimum antenna receiving power characteristic polarization as an antenna polarization state, calculating an antenna receiving power of each pixel; 3, calculating the center of each class; 4, calculating a polarization scattering difference measurement of each pixel, judging the pixel as a class with the minimum difference measurement; and 5, checking whether the ending condition is reached, and if not, returning the step 4. According to the POLSAR image unsupervised classification method based on target scattering identification, the scattering of the ground features can be more accurately described and can well correspond to the actual scattering condition of the ground features, thus the operation time of class regulation is reduced.

The invention relates to a reflect array antenna, which comprises a feed source pyramidal horn and a reflecting surface array, wherein the reflecting surface array is formed by periodically arranging a plurality of antenna units in a mirror symmetry manner in sequence; each antenna unit comprises a micro-strip patch and a bottom plate; the micro-strip patch is located on the bottom plate and further comprises nested three circular rings and two phase delay lines; two gaps which are centrally symmetrical relatively are formed in each of three circular rings; each of the two phase delay lines is in an arc form, and is connected with a micro-strip stub on the outer circular ring of the micro-strip patch; and the connecting line of the micro-strip stubs is parallel to a polarization direction of the antenna. According to the reflect array antenna, the reflect array antenna with a relatively high bandwidth can be achieved by combining the advantages of different structures.

A networked radio frequency identification system includes a plurality of radio frequency identification (RFID) tag readers, a computer in signal communication with the RFID tag readers over a network, and a software module for storage on and operable by the computer that localizes RFID tags based on information received from the RFID tag readers using a network model having endpoints and oriented links. In an additional example, at least one of the RFID tag readers includes an adjustable configuration setting selected from RF signal strength, antenna gain, antenna polarization, and antenna orientation. In a further aspect, the system localizes RFID tags based on hierarchical threshold limit calculations. In an additional aspect, the system controls a locking device associated with an access point based on localization of an authorized RFID tag at the access point and reception of additional authorizing information from an input device.

The invention belongs to the field of planar transmitting array antennas, and discloses a low-profile and high-efficient polarization transformation transmitting array antenna. The low-profile and high-efficient polarization transformation transmitting array antenna comprises: a pyramidal horn antenna used as a feed of the transmitting array antenna, and double-layer and three-dimensional portion symmetrical cross oscillators of different sizes used as transmitting array cells. The double-layer and three-dimensional portion symmetrical cross units proposed by the invention have the capability of transforming among multiple polarization modes and small transmission loss. The transmitting array antenna formed by the proposed three-dimensional portion symmetrical cross oscillator units overcomes the shortage of a single polarization mode of the conventional transmitting array antenna, and can realize various polarization modes (including linear polarization and circular polarization). The aperture using efficiency of the antenna in various polarization modes is up to 54% or more, and the longitudinal section height thereof is also reduced significantly compared with that of the conventional transmitting array antenna, so that the development and application of the transmitting array antenna technology are effectively promoted.

The invention discloses an automatic measuring system and an automatic measuring method of a fuze antenna far field. The system comprises an antenna receiving turntable subsystem, a transmitting polarizer subsystem, a transmitting and receiving subsystem, a servo drive digital display subsystem and a computer subsystem, wherein the antenna receiving turntable subsystem is respectively connected with the transmitting and receiving subsystem and the servo drive digital display subsystem, the transmitting polarizer subsystem is respectively connected with the transmitting and receiving subsystem and the servo drive digital display subsystem, and the computer subsystem is respectively connected with the transmitting and receiving subsystem and the servo drive digital display subsystem. The antenna receiving turntable subsystem comprises an azimuth turntable, a one-dimensional translation device which is arranged above the azimuth turntable, a support which is fixedly connected to the top of the one-dimensional translation device and an antenna polarizer which is installed on the top end of the support. With the adoption of the system, the automatic measurement and control of a fuze antenna can be realized, the long-time manual operation can be avoided, and the test efficiency is greatly improved.

The present disclosure provides a rotating-polarization reflector-backed Radio Frequency Identification (RFID) loop antenna apparatus and method. The loop antenna apparatus and method provides high gain (i.e., maximizing read distances at lowest power), directionality (i.e., ability to focus on specific areas), orientation insensitivity (i.e., ability to read RFID tags in any direction or orientation) while occupying minimal volume in overhead configurations. In an exemplary embodiment, the loop antenna apparatus includes a reflector and a loop element with the reflector configured to reflect downward RF energy from the loop element. Antenna polarization is controlled by a feed location on the loop element and antenna pattern is controlled by the reflector. Thus, orientation insensitivity may be achieved without changing the antenna pattern by rotating the feed location and not the reflector.

The invention provides a polarization tracking method and tracking system for a mobile satellite communication antenna. The system comprises the satellite communication antenna comprising a receiving antenna and a transmitting antenna which are used for receiving and transmitting orthogonal polarization satellite signals respectively; a polarization isolation degree measurement portion which is used for obtaining and measuring signal levels of the pair of orthogonal polarization signals, calculating the ratio of the obtained signal levels and making a comparison between the ratio and the predetermined threshold value; and a tracking control portion which is used for controlling the antenna to emit and receive polarization angle adjustment synchronously according to the comparison result output from polarization isolation degree measurement portion. The polarization isolation degree measurement portion comprises an orthogonal polarization signal decomposition portion which is used for carrying out decomposing processing to generate a pair of mutually-orthogonal polarization signals according to satellite signals received from the receiving antenna.

The invention, which belongs to the field of radio technology, provides a broadband low-profile vertical polarization omnidirectional antenna with characteristics of antenna polarization size reduction and good broadband performance. The broadband low-profile vertical polarization omnidirectional antenna comprises a metal floor, a metal circular-truncated-cone-shaped sleeve, a round loading plateand a feeding coaxial line. The circular bottom surface of the metal circular-truncated-cone-shaped sleeve is fixed in the middle of the metal floor; an outer coaxial part of the feeding coaxial linepasses through the bottom of the metal floor and then is connected with the metal circular-truncated-cone-shaped sleeve; and the top of an inner coaxial part of the feeding coaxial line is connected with the round loading plate. In addition, the broadband low-profile vertical polarization omnidirectional antenna also includes short-circuit metal posts and open-circuit metal posts; the short-circuit metal posts enable currents of the round loading plate to be led to the metal floor in a short-circuit manner; and the open-circuit metal posts arranged on the metal floor are used for realizing opening circuit of the current of the metal floor. Because of loading processing on the top of the monopole antenna of the metal circular-truncated-cone-shaped sleeve, the broadband low-profile effect isrealized, so that the antenna has the good broadband performance.

An active polarized tracker in a high-accuracy low-noise Ku frequency band enables the antenna polarization tracking function in a movement state to be achieved. The active polarized tracker comprises a low-noise amplifying circuit, a polarization control circuit, a power supply circuit and a phase shifter control circuit. The receiving and amplifying function of antenna signals can be achieved through the low-noise amplifying circuit, the phase correction and polarization tracking function can be achieved by the polarization control circuit, power is supplied to the low-noise amplifying circuit, a digital phase shifter and other devices by the power supply circuit, and a phase shifting state of the digital phase shifter is controlled through the phase shifter control circuit. Cross polarization interference of a communication-in-moving receiving antenna is adjusted and eliminated, so that the communication quality of a mobile satellite is improved.