69 results about "Surface wave propagation" patented technology

A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

A surface acoustic wave device that is small, lightweight and highly reliable, and protects its functional portion. The surface acoustic wave device has surface acoustic wave elements mounted on a circuit substrate. Each surface acoustic wave element includes a frame-like first insulating film furnished to surround functional portions on a chip, and a lid-like second insulating film deposited on the first insulating film so as to cover driving electrodes and surface wave propagation paths of the functional portions, while securing a hollow portion over the functional portions.

A communication system includes the following elements: a transmitter including a transmission circuit unit configured to generate an RF signal for transmitting data and an electric-field-coupling antenna configured to transmit the RF signal as an electrostatic field; a receiver including an electric-field-coupling antenna and a reception circuit unit configured to receive and process the RF signal received by the electric-field-coupling antenna; and a surface-wave propagation medium configured to provide a surface-wave transmission line to transmit a surface wave emanating from the electric-field-coupling antenna of the transmitter with low propagation loss.

The invention relates to a low-cross coupling groove array antenna which has the basic principle that a pair of surface groove structures is symmetrically loaded at both sides of adjacent array unitsto modulate the surface wave propagation, and the distribution of surface electromagnetic energy is changed, thereby enabling the energy disturbance among array elements to be quickly reduced. In addition, partial surface electromagnetic energy is radiated to free space with the dispersion of an SPs groove structure, thus increasing the antenna gain, and compressing the wave beam width of the antenna, and therefore, the radiation performance of the antenna is obviously improved. Compared with a structure traditionally restraining surface wave, the novel groove wave-guide gap SP antenna has simple structure and low cost, and the radiation performance such as antenna gain and the like is increased when the surface wave is restrained at the same time. The invention can be widely applied to linear array antenna, area array antenna, phased array antenna and the like.

An antenna apparatus includes a patch antenna unit in which a radiation conductor and a ground conductor plate are arranged so as to face each other with an insulating material disposed therebetween, a power-feed point is provided at a position slightly offset from the center of the radiation conductor, and a high-frequency electric field is supplied between the radiation conductor and the ground conductor plate; a surface-wave propagation suppression area in which a surface-wave propagation suppression mechanism for suppressing surface-wave propagation is mounted in an outer surrounding area in the offset direction of the power-feed point in which an electric-field intensity is generally maximum within the end portion of the radiation conductor plate; and an insulating area in which an electric-field intensity between the radiation conductor plate and the ground conductor plate is relatively low and the surface-wave propagation suppression mechanism is not arranged.

A surface acoustic wave resonator has a quartz crystal substrate having Euler angles of (φ=0°, 110°≦θ≦150°, 88°≦ψ≦92°) and an IDT having a plurality of electrode fingers disposed on the quartz crystal substrate, and using a surface acoustic wave as an excitation wave, a plurality of grooves arranged in a propagation direction of the surface acoustic wave to form stripes is disposed on the quartz crystal substrate, and the electrode fingers are disposed one of between the grooves and inside the grooves.

The invention discloses a dual-polarization base station antenna based on photonic crystals. The dual-polarization base station antenna comprises a dielectric substrate. A grounded plate is arranged on the back of the dielectric substrate. Two antenna arrays are arranged side by side at the center of the front through a balun. A photonic crystal reflection panel extends along the vertical direction on the edge of the front of the dielectric substrate. A photonic crystal separation plate extends along the vertical direction on the dielectric substrate between the antenna arrays. Guide plates are arranged on the outer side of the photonic crystal reflection panel and the back of the photonic crystal separation plate. A number of metal patches which are periodically arranged are respectively arranged on the inner side of the photonic crystal reflection panel and positions corresponding to the guide plates on the front of the photonic crystal separation plate. Conductive through holes are arranged between the metal patches and the guide plates. According to the antenna provided by the invention, a broadband effect is realized; through the photonic crystal reflection panel and the photonic crystal separation plate, surface wave propagation can be reduced; coupling between the antenna arrays is reduced; and the total weight of the antenna is greatly reduced.

The invention relates to the roll quality detection field, in particular to a nondestructive detection method for a roll fatigue hardening layer. The ultrasonic surface wave nonlinear detection method for the roll fatigue hardening layer includes: firstly preparing series of standard test blocks with different fatigue hardening layer thicknesses, conducting surface acoustic wave second harmonic detection on the known series of standard test blocks with different fatigue hardening layer thicknesses to obtain a monotonous corresponding relation between the second harmonic strength and the hardening layer thickness, employing acoustic surface wave to detect a test roll, and comparing the result with the corresponding relation to obtain a corresponding thickness value of the fatigue hardening layer. By adopting nonlinear second harmonic generation effects in an ultrasonic surface wave propagation process, the method provided by the invention realizes detection of the roll fatigue hardening layer, and provides an effective nondestructive detection means for quantitative evaluation of the roll fatigue hardening layer. With accurate and reliable detection results, the method can well cooperate with the grinding optimization work of a roll at a steel production spot, saves the production cost and ensures production safety.

The invention discloses a nondestructive detecting method for surface defects of plate structures. The nondestructive detecting method for surface defects of plate structures comprises the following steps: building a sensor array by specially-made surface wave sensors to perform defect detecting and imaging on a region to be detected of the surface of a plate structure; arranging eight surface wave sensors according a linear array, and mounting the eight surface wave sensors on the surface of the plate structure by smearing coupling agents; exciting the first surface wave sensor, and receivingand acquiring eight defect echo signals by all the sensors; successively exciting the various sensors in the array, and repeating the acquiring process to acquire 64 defect echo signals; uploading the 64 echo data to a computer, and carrying out defect imaging processing on the 64 echo data by using a full-focusing imaging algorithm so as to judge whether the surface defects exist or not. The nondestructive detecting method has the advantages that the problem that the detection requirements of a plurality of collinear defects existing on a surface wave propagation path cannot be satisfied bya single surface wave sensor under special working conditions is solved; the nondestructive detecting method is high in detection sensitivity, does not need mobile sensors and saves a large number ofmanpower and material resources.

The invention, which belongs to the technical field of the radar and wireless communication, discloses an electromagnetic-bandgap-structure-based large-unit interval wide-angle scanning phased array antenna. Antenna units are distributed in a triangular grid manner. An upper dielectric plate, an intermediate dielectric plate, and a lower metal floor are arranged. The intermediate dielectric platewith the upper surface printed with a micro-strip feeder line is in contact with the metal floor having the upper surface with a connection groove. A coaxial line inner core is connected with a feed point of the micro-strip feeder line; the other end of the micro-strip feeder line is arranged above the connection groove to carry out coupled feeding. A metal strip line is printed on the upper surface of the upper dielectric plate. Besides, an electromagnetic bandgap structure for suppressing surface waves is arranged between the upper dielectric plate and the metal floor. On the basis of the electromagnetic bandgap structure, a scanning blind point is eliminated effectively by means of suppressing surface wave propagation, so that the wide angle and wideband characteristics are realized. The phased array antenna has advantages of large unit dimension and simple structural mode; and the manufacturing cost of the large phased array antenna in actual application can be reduced substantially.

The invention provides a surface wave yagi antenna, which is characterized in that the excitation electromagnetic energy is TM surface waves, the surface wave yagi antenna comprises a dielectric layer, a surface wave transmitter, a surface wave director and a surface wave reflector, wherein the dielectric layer is used for supporting surface wave propagation, the surface wave transmitter is used for directionally transmitting surface waves, the surface wave director is used for directionally guiding and enhancing the surface waves, the surface wave reflector is used for directionally reflecting and suppressing the surface waves, one side of the dielectric layer is grounded, the surface wave transmitter, the surface wave director and the surface wave reflector are located on the other sideof the dielectric layer, the surface wave director and the surface wave reflector are respectively located at two sides of the surface wave transmitter. The compact surface wave antenna with a V-shaped surface wave director or a surface wave reflector is respectively designed based on the printed-monopole surface wave transmitter, so that the antenna structure is enabled to be more compact. The surface wave yagi antenna can also add a graphene layer to serve as a surface wave absorbing material at the side where surface waves need to be suppressed so as to reduce the backward and lateral radiation.

Disclosed is a single crystal substrate and a cutting method thereof. A single crystal substrate includes a langasite substrate with a SAW propagation surface; and input and output IDTs having electrodes on the surface for launching and/or detecting surface acoustic waves, wherein a direction of surface wave propagation is parallel to an X'axis, and the substrate further has an Z'axis perpendicular to the surface and a Y'axis parallel to the surface and perpendicular to the X'axis, the langasite substrate having a crystal orientation defined by modified axes X, Y and Z, the relative orientation of axes X', Y' and Z' being defined by Euler angles phi, theta and psi; wherein, phi is equal to or greater than 5 DEG C below zero and equal to or less than 5 DEG C; theta is equal to or greater than 60 DEG C and equal to or less than 80 DEG C; psi is equal to or greater than 5 DEG C below zero and equal to or less than 5 DEG C; or phi is zero DEG C; theta is equal to or greater than 17 DEG C and equal to or less than 23 DEG C; psi is equal to or greater than 10 DEG C below zero and equal to or less than 20 DEG C.

An acoustic wave filter device includes a piezoelectric substrate and a longitudinally coupled resonator surface acoustic wave filter unit provided on the piezoelectric substrate. The surface acoustic wave filter unit includes first to fifth IDTs arranged in a surface wave propagation direction. The first, third, and fifth IDTs are connected to an unbalanced terminal, while the second and fourth IDTs are connected to first and second balanced terminals, respectively. The second IDT includes first and second sub-IDT portions obtained by dividing the second IDT and arranged in a crossing width direction, and the fourth IDT includes first and second sub-IDT portions obtained by dividing the fourth IDT and arranged in the crossing width direction. The first and second sub-IDT portions are connected in series. The first and second sub-IDT portions are also connected in series.

The invention discloses a novel choking coil center feed double-frequency circularly polarized GPS antenna. The antenna comprises a center feed double-frequency circularly polarized GPS antenna and anovel choking coil. Compared with an existing choking coil structure with coaxial corrugated grooves only placed in the horizontal direction, the antenna employs the novel choking coil structure; thetwo layers of longitudinal radial corrugated grooves are additionally formed in the vertical direction, the two layers of longitudinal radial corrugated grooves are placed below the two layers of horizontal coaxial corrugated grooves, and therefore the diameter of the whole choking coil is effectively reduced; the surface wave propagation on the grounding plate on the back of the antenna can be effectively inhibited, and the back lobe of the antenna is reduced, so that the front-to-back ratio and the back lobe of the antenna are improved, and the antenna is very suitable for high-precision satellite navigation and positioning systems.

Various embodiments are provided for site specification for directional guided surface wave transmission in a lossy media. In one embodiment, a probe site includes a propagation interface including first and second regions comprising different lossy conducting mediums; and a guided surface waveguide probe which is positioned adjacent to the first and second regions and can generate at least one electric field to launch a guided surface wave along the propagation interface in a radial direction defined by the first region and restricted by the second region. The propagation interface can also include additional regions comprising the same or different lossy conducting mediums. One or more of the regions can be prepared regions. In some cases, the regions can correspond to a terrestrial medium (e.g., a shoreline) and water (e.g., seawater along the shoreline).

The invention provides a surface acoustic wave filter with a discontinuous substrate structure. The surface acoustic wave filter comprises the following structures: 1) a substrate layer 1; 2) a piezoelectric film layer 2 arranged on the substrate layer, and an acoustic impedance discontinuous layer 3 contained in the piezoelectric film layer 2; and 3) an interdigital transducer 4 arranged on the piezoelectric film layer. Through the surface acoustic wave filter of the invention, the acoustic impedance condition can be changed or periodic design can be carried out on the propagation path of the surface acoustic wave device (SAW), and the propagation characteristic of the surface acoustic wave is modulated, so that the improvement of the performance indexes such as the quality factor (Q value), the bandwidth and the insertion loss of the surface acoustic wave filter is finally realized. Compared with a traditional single crystal material, the piezoelectric film is adopted, the price is lower, and a gap space with discontinuous acoustic impedance can be easily prepared no matter a stripping process or an etching process is adopted.

The invention discloses a high electromechanical coupling coefficient acoustic surface wave device based on a double-layer electrode and a preparation method thereof. The acoustic surface wave deviceis structurally characterized in that a copper electrode, a piezoelectric film and an aluminum electrode are sequentially arranged on a substrate, a signal terminal of the copper electrode correspondsto a grounded terminal of the aluminum electrode, and the piezoelectric film is a zinc oxide film. Due to the fact that the adopted Sezawa wave mode is formed by coupling film thickness vibration andtransverse vibration, the acoustic surface wave device has the characteristics of changing the coupling mode of electric fields and the piezoelectric film by exciting a longitudinal electric field (in the film thickness direction) and a transverse electric field ( in the acoustic surface wave propagation direction) through the double-layer electrode, thereby raising the electromechanical couplingcoefficient of the acoustic surface wave device.

The invention discloses an equipment conformal slot coupled antenna based on a liquid crystal adjustable material. The antenna adopts a Minkowski fractal microstrip structure, so the electric length of the radiation patch is increased, the size of the antenna unit is reduced, the influence of curved surface curvature change on antenna radiation is reduced, the bandwidth of the antenna unit is improved by adopting a strip line slot coupling feed structure, the surface wave loss of the antenna unit is reduced, and a radiation element and a feed network are better isolated; by designing the rectangular slot gap in the floor layer, surface wave propagation between antennas can be suppressed, and coupling between conformal array antenna units is effectively reduced; by designing the liquid crystal tuning circuit, the liquid crystal is applied to the antenna unit, electric tuning is carried out to change the equivalent dielectric constant of the liquid crystal, frequency reconfiguration is realized, and the anti-interference capability of the equipment conformal antenna is improved, so the bandwidth and gain of the existing antenna are improved, and the radiation influence is reduced.