134 results about "Log-periodic antenna" patented technology

There is disclosed an automobile hang tag for use in parking control and the like with an integral radio transponder, together with interrogator apparatus associated therewith in a system for parking control or other purposes. The detection range for the RFID interrogator and transponder is at least about six meters (20 feet) to enable rapid control monitoring of parking facilities from a moving vehicle through the back window or front windshield of parked vehicles. Reliable and trouble-free monitoring of the hang tags in a customary rear view mirror location is facilitated by employing directional antennas in the RFID hang tags, increasing the antenna gain while suppressing false signals and noise and improving the range-to-power ratio for the system. The RFID hang tags may be battery powered but are preferably unpowered RFID transponders. Suitable directional antennas employed may include Yagi antennas, log periodic antennas, stacked dipole antennas, spiral or slot antennas or other monodirectional or bidirectional antennas, preferably those suitable for selected frequencies within the 1,000 megahertz to 10,000 megahertz range.

The invention discloses a room-temperature adjustable sub-Terahertz wave detector and a preparation method. A graphene field effect transistor with high migration rate and adjustable carrier concentration is taken as a basic structure unit, and the field effect transistor is provided with a group of source and drain electrodes and cleavage grid electrodes of a sub-Terahertz wave coupled antenna. The detector is integrated with log-periodic antennas and corresponding feed electrodes on a sapphire substrate; the detector is provided with a graphene conducting channel transferred in an antenna distance; an aluminum oxide gate dielectric layer is arranged on the graphene conducting channel, and finally the cleavage grid electrodes and the corresponding lead electrodes are integrated on the aluminum oxide gate dielectric layer of the graphene conducting channel, so that adjustable sub-Terahertz wave detection is realized. The detector has the advantages that the detector is an adjustable lightguide-like and photovoltaic-like detector with high speed, wide band and high response; and the integration level, technical maturity and repeatability of the device lay the foundation of large-scale application of Terahertz detectors.

A CPW fed planar log-periodic antenna is provided. The antenna includes: an upper substrate; a planar log-periodic antenna structure formed beneath the upper substrate; a CPW-fed structure formed on the upper substrate for feeding energy into the planar log-periodic antenna structure; a lower substrate disposed beneath the upper substrate; and a wire structure formed beneath the lower substrate. The antenna of the present invention features efficient reduction of cross polarized radiation and thereby enhancing the performance.

A log-periodic antenna coupled to a channelizer is described in which matched scale constants for the antenna and the channelizer are used to achieve substantially identical coupling over each fractional bandwidth channel. Embodiments for simultaneous dual polarization operation are described as well as embodiments suited for planar lithographic fabrication.

The invention discloses a method for predicting electrical properties of deformed log-periodic antennae based on an electromechanical coupling model, aiming to mainly solve the problem of electromechanical separation in the log-periodic antennae. The method comprises the following steps: building a finite element model based on the structural design parameters of the log-periodic antennae, loading dead load, random wind and other environmental loads and carrying out finite element analysis to obtain the structure displacement field of the log-periodic antennae; utilizing the analysis results to obtain current distribution of oscillator units in the log-periodic antennae and phase difference caused by the positions and deflection of the oscillator units and computing the far field patternsof the log-periodic antennae according to the superposition theorem; and obtaining the electrical property parameters of the log-periodic antennae to realize electromechanical coupling analysis of the log-periodic antennae. The method can help the log-periodic antenna structural design personnel improve the antenna design and manufacturing quality.

An array of backward diodes of a cathode layer adjacent to a first side of a non-uniform doping profile and an Antimonide-based tunnel barrier layer adjacent to a second side of the spacer layer have a monolithically integrated antenna bonded to each backward diode. The Antimonide-based tunnel barrier may be doped with, for example, a non-uniform delta doping profile. An imaging/detection device includes a 2D focal plane array of an array of backward diodes, wherein each backward diode is monolithically bonded to an antenna, which array is located at the back of an extended hemispherical lens, and wherein certain of the arrays are tilted for correcting optics aberrations. The antennas may be a bow-tie antenna, a planar log-periodic antenna, a double-slot with microstrip feed antenna, a spiral antenna, a helical antenna, a ring antenna, a dielectric rod antenna, or a double slot antenna with co-planar waveguide feed antenna.

The invention discloses a graphene room temperature terahertz wave detector, and the detector comprises a sapphire substrate, log-periodic antennas formed on the sapphire substrate through evaporation, and lead electrodes. Moreover, two sides of the terahertz wave coupling log-periodic antennas are respectively connected with the corresponding lead electrode. A graphene conductive trench with adjustable carrier concentration and high migration rate is disposed in a gap of the log-periodic antennas in a transfer manner, thereby guaranteeing the interconnection between graphene and the log-periodic antenna at two sides. The detector is advantageous in that the detector is high in terahertz wave response, can achieve the detection of broadband, high speed, high sensitivity and high signal to noise ratio terahertz waves; the detector is good in integration and miniaturization, and lays a foundation for the large-scale application.

The invention discloses a short wave logarithm three-dimensional array antenna system which comprises an antenna main body system, an antenna bearing system and an antenna control system. The antenna main body system comprises an antenna array which is formed by a plurality of logarithm cycle antennas arrayed in an included-angle mode. The antenna bearing system comprises a supporting device used for bearing, rotating and turning the antenna array. The antenna control system comprises a rotating control device which controls a supporting unit to rotate and turn. Based on the great features of the logarithm cycle antennas, a logarithm cycle antenna vertical sector array is designed, so that structure is simple, functions are flexible, the performance index is high, occupied space is low, the frequency band is wide, power is high, gain is high, and 360-degree horizontal rotating and 180-degree vertical turning can be achieved.

A log periodic antenna includes first and second transmission lines parallel with each other; and a plurality of broadband radiation elements having first sides electrically connected to the first and second transmission lines, a predetermined angle being defined between the first sides of the broadband radiation elements and the first and second transmission lines, and second sides not electrically connected with the first and second transmission lines, the second sides having radiation surfaces larger than radiation surfaces of the first sides. A plurality of broadband radiation elements electrically connected with the first transmission line and a plurality of broadband radiation elements electrically connected with the second transmission line are positioned to face each other with reference to the first and second transmission lines.

The invention provides a printed unipolar folded oscillator log periodic antenna, relates to a log periodic antenna, particularly relates to the printed unipolar folded oscillator log periodic antenna, and aims at solving problems that a common printed log periodic antenna is oversized. The printed unipolar folded oscillator log periodic antenna comprises a dielectric substrate, a front surface first inverted U-shaped microstrip line, a front surface second inverted U-shaped microstrip line, a front surface third inverted U-shaped microstrip line, a front surface fourth inverted U-shaped microstrip line, a front surface fifth inverted U-shaped microstrip line, a front surface sixth inverted U-shaped microstrip line, a front surface seventh inverted U-shaped microstrip line, a front surface eighth inverted U-shaped microstrip line, a front surface ninth inverted U-shaped microstrip line, a front surface tenth inverted U-shaped microstrip line, a front surface strip-shaped microstrip line, a back surface first strip-shaped microstrip line and a back surface second strip-shaped microstrip line. The printed unipolar folded oscillator log periodic antenna is used for the field of wireless communication.

The invention belongs to the technical field of dual-circular-polarization antennas, and discloses a wide-beam UWB (ultra wide band) dual-circular-polarization log-periodic antenna. The antenna is provided with a UWB radiator and a reflection cavity. The UWB radiator is located at the upper part of the antenna. The reflection cavity is coaxial with the UWB radiator, and is located at the lower part of the antenna. The reflection cavity and the UWB radiator are arranged at an interval. The interior of the reflection cavity is provided with two UWB feed Baluns and one UWB 3dB bridge, and a wirepasses through a through hole on the upper surface of the reflection cavity to achieve the feed of the UWB radiator. Line impedance bandwidth reaches three frequency multiplications or more, and the broadband half-power wave beam width is greater than 110 degrees. The gain of the radiation main lobe of the antenna is 0dBic or more within 130 degrees. The antenna is compact in overall structure, isexcellent in performance, and is suitable for a high-performance wireless communication system.

A self-similar log-periodic antenna is described comprising a plurality of substantially triangular conductive elements, 4, symmetrically disposed in either planar or curved configurations about a central conductive boom to form an antenna arm. Two or more antenna arms are assembled into an antenna by symmetrically locating such antenna arms substantially in the shape of a pyramid (for planar arms) or in a conical shape (for curved arms). Some embodiments include a conductive fin, 5, to reduce cross-polarization coupling between antenna arms. Some embodiments include a grounded conductive shield on the interior of the antenna providing electromagnetic shielding for the interior region of the antenna while preserving the self-similar geometry of the antenna and shield combination.

The invention relates to a tree-shaped antenna, which comprises two feeding poles and more than three pairs of oscillators, wherein each pair of oscillators are in one step; the more than three pairs of oscillators are increased step by step from top to bottom; the upper ends of two feeding poles are connected to form a herringbone; each pair of oscillators are respectively and symmetrically installed on the two feeding poles; each pair of oscillators have the same structure but different sizes; the oscillators are one-stage fractons or two-stage fractons; each fracton comprises three fraction arms which are successively connected and are in the horizontal pole shape; the junction of adjacent fracton arms is provided with a vertically-upward fracton arm or a vertically-downward fracton arm; the lengths of the fracton arms are equal; one end of three successively-connected fracton arms is connected with one feeding pole, and the other end is connected with a one-stage loading metal bar. According to the tree-shaped antenna disclosed by the invention, the volume of the antenna is greatly reduced, the problem that the common metre wave log-periodic antenna can not be suitable to install on an airborne platform is solved, antenna cross coupling is lowered, and the electrical property can satisfy the system use requirement.

The invention discloses a wideband printed miniature log periodic antenna and relates to the ultra wideband antenna miniaturization technology. The wideband printed miniature log periodic antenna aims to solve the problem that an existing log periodic antenna is over large in size, and consequently a printed circuit board is large in size. The two sides of a feeder line of the antenna are provided with 14 arrays in total, wherein the seven arrays on one side are sequentially numbered from number one to number seven in the direction from the short arrays to the long arrays, and the seven arrays on the other side are sequentially numbered from number eight to number fourteen in the direction from the short arrays to the long arrays; the number one array, the number two array, the number three array, the number eight array, the number nine array and the number ten array are respectively in a line shape; the number four array, the number five array, the number eleven array, the number twelve array and the number thirteen array are respectively in a T shape; the number six array, the number seven array and the number fourteen array are respectively of an inverted-E shape. By means of optimizing the size of the antenna, the size can be reduced by over 50%, so that the size of the printed circuit board is greatly reduced. The wideband printed miniature log periodic antenna is suitable for wideband wireless transmission.

This invention discloses a UHF/VHF high gain and wide band directional antenna applying two same T shaped vibrator log-periodic antennas made of T shaped vibrators arrayed in two-element array structure of a cone and mounted on a metal earth plate connected by two metallic connecting strips at the top and feeding signals with a hard coaxial cable, in which, every antenna is composed of seven T shaped vibrators, a medium fixing plate, two metallic supporting frames and two medium supporting blocks.

The embodiment of the invention provides a system and method for testing the electromagnetic disturbance of a rail transit vehicle to an external environment. The system comprises a loop antenna which receives a magnetic field strength signal of the rail transit vehicle to the external environment and transmits the magnetic field strength signal to a receiver, a double cone antenna, a logarithmic antenna and the receiver. The double cone antenna and the logarithmic antenna receive an electric field strength signal of the rail transit vehicle to the external environment and transmit the electric field strength signal to the receiver. The receiver receives the magnetic field strength signal and the electric field strength signal in a quasi-peak detector mode, tests the electromagnetic disturbance of the rail transit vehicle under a static working condition to the external environment. In a spectrometer peak detector mode, the magnetic field strength signal and the electric field strength signal are received to test the electromagnetic disturbance of the rail transit vehicle under a dynamic working condition to the external environment. According to the invention, the static working condition test and the dynamic working condition test of the rail transit vehicle are realized through the receiver in the quasi-peak detector mode or the spectrometer peak detector mode.

The invention relates to the technical field of a polarization-sensitive array antenna, in particular to an active and passive combined polarization sensitive array antenna device with a compact structure. An installation platform is arranged, the active and passive combined polarization sensitive array antenna device with the compact structure is characterized in that an active radar antenna anda passive radar antenna are arranged, wherein the active radar antenna employs a coplanar waveguide (CPW) feeding-based dual-polarization square microstrip patch antenna, the passive radar antenna employs a miniature log periodic antenna LPDA, the LPDA of a printed circuit structure is employed, the active radar antenna is arranged at a central part of round aperture, a broadband passive antenna array is arranged at an edge part of the round aperture, a random layout mode in a circumferential direction is employed, and a metal grid mesh-type electromagnetic isolation device is also employed. The active and passive combined polarization sensitive array antenna device is applicable to satellite-borne, onboard, missile-borne and other relevant wireless direction finding systems, and has morecomprehensive parameter measurement function and platform adaptability.

The invention discloses an H-face array shortwave logarithm three-dimensional array antenna which comprises an antenna array and a supporting frame used for erecting the antenna array. The antenna array comprises multiple logarithm periodic antenna units which are arranged according to a preset included angle and are in fan-shaped distribution, the supporting frame comprises multiple horizontal trusses which are arranged correspondingly to the logarithm periodic antenna units and are in fan-shaped distribution, and vertical trusses used for fixing the horizontal trusses, the logarithm periodic antenna units are arranged on the corresponding horizontal trusses respectively, and each logarithm periodic antenna unit comprises an assembly line arranged along the corresponding horizontal truss and antenna oscillators sequentially arranged on the assembly line according a sequence from short to long. A system has the advantages of wide band, high power and high gain, and the antenna of the system is simple in structure and convenient to operate and has extremely excellent application prospect.

The invention discloses a logarithmic period antenna that can be automatically unfolded and stored, and relates to a high-gain directional vehicle-mounted or fixedly installed antenna device in the field of communication countermeasures. It consists of log-periodic antenna, electric antenna mast and other components. It uses a vibrator retractor to realize the expansion and storage of the antenna vibrator as the electric antenna mast is raised and lowered, so as to realize the automatic expansion and storage of the logarithmic period antenna. The invention has the characteristics of small storage height, simple structure, reliable performance, etc., and is especially suitable for use as a high-gain vehicle-mounted or fixed-installation antenna in the ultrashort-wave frequency band.

This disclosure relates to monolithic focal plane arrays including an antenna coupled to a backwards diode to make large scale arrays. The antennas may be, for example, a bow-tie antenna, a planar log-periodic antenna, a double-slot with microstrip feed antenna, a spiral antenna, a helical antenna, a ring antenna, a dielectric rod antenna, or a double slot antenna with co-planar waveguide feed antenna. There is no restriction on the type of antenna coupled with the backwards diodes to make monolithic large scale arrays.

Disclosed is a log periodic antenna and a manufacturing method thereof. In the log periodic antenna, antenna elements are attached to an antenna body to thereby simplify a structure of the antenna, the antenna can be manufactured in various designs without restriction to the configuration of the antenna, and the number of contacting points between the antenna element and a feeder is minimized to thereby simplify the manufacturing process. By the antenna, it is possible to produce the log periodic antenna of the simple structure and of various designs without the restriction to the antenna configuration by attaching the signal pattern and ground pattern to the pattern receiving surface.

The invention relates to an automatic arraying control device of a log-periodic antenna array and an arraying method thereof. The automatic arraying control device comprises an antenna lifting mechanism, the log-periodic antenna array, a plurality of plug pin driving mechanisms, a plurality of pin hole detection mechanisms, a plurality of antenna folding and unfolding mechanisms and a control module. The lifting mechanism comprises a supporting table and a lifting arm. The lifting arm comprises a plurality of arm shafts, every two adjacent arm shafts are movably connected and pin holes are formed in the arm shafts. The log-periodic antenna array comprises a plurality of layers of antennas, each layer of antenna is provided with a connecting part, the connecting part of each layer of antenna is provided with a plug pin and each layer of antenna is movably connected with one arm shaft. Each plug pin driving mechanism is arranged on one connecting part and is connected with the plug pin.The pin hole detection mechanisms are installed at the position close to the plug pins of the connecting parts. Each antenna folding and unfolding mechanism is installed on one layer of antenna. The control module is electrically connected with the pin hole detection mechanisms, the plug pin driving mechanisms, the antenna lifting mechanism and the antenna folding and unfolding mechanisms. Automatic and accurate array forming can be realized and safety and reliability can be achieved.