44 results about "Surface acoustic wave transducers" patented technology

An acoustic wave sensor array device is provided for the detection, identification, and quantification of chemicals and biological elements dispersed in fluids. The sensor array device is capable of the simultaneous characterization of a fluid for multiple analytes of interest. A substrate has a plurality of channels formed therein and a sensor material layer applied in a bottom of the channels. The sensor material layer has a shear acoustic wave speed lower than a shear acoustic wave speed in said substrate. The channels may have the same material in each channel or different materials in at least two of the channels. A surface acoustic wave transducer and at least one surface acoustic wave reflector, or at least two transducers is formed on a surface of the substrate opposite the channels at a portion of the substrate that is thinned by the channels, so that the acoustic tracks of the surface acoustic wave device extend along the channels. The response of the surface acoustic wave depends on the response of the sensor material to a sensed fluid supplied to the channels.

A system for tracking the position of multiple objects in three dimensional space by transmitting radar interrogation signals having predetermined wave shapes to surface acoustic wave transducers attached to each object. Each transducer includes a unique electrically conductive pattern on one surface of a piezoelectric substrate for selectively responding to the predetermined wave shape of one of the interrogation signals for inducing a surface acoustic wave in the substrate and for thereafter transforming the surface acoustic wave into an electromagnetic response signal having detectable properties that uniquely identify said transducer. The location of each transducer is estimated by measuring the time-of-flight or angle-of-arrival of the radar signals at several measurement stations and producing a position estimate by triangulation.

The invention discloses a surface acoustic wave transducer with a transverse mode suppression function and a preparation method thereof. The invention relates to the field of surface acoustic wave devices and manufacturing thereof. The structure comprises a piezoelectric substrate and an interdigital transducer arranged on the piezoelectric substrate. The interdigital transducer comprises a firstinterdigital electrode, a second interdigital electrode, a first bus bar and a second bus bar, wherein the first interdigital electrode and the second interdigital electrode are crossed. According tothe structure of the interdigital transducer, the interdigital transducer is further divided into an interdigital region, a first single-finger region and a second single-finger region; grooves are formed in interdigital gaps between adjacent interdigital electrodes in the interdigital region, and the grooves are located in the interdigital regions at the junctions of the interdigital region and the edges of the first single-finger region and the second single-finger region respectively; by forming the grooves, the sound velocity of the edge of the interdigital region of the surface acoustic wave transducer is lower than that of the center of the interdigital region, and the sound velocity of the first single-finger region and the second single-finger region is higher than that of the center of the interdigital region, so that the transverse wave mode of sound waves can be effectively inhibited; clutter response is inhibited; and the performance of the surface acoustic wave transduceris greatly improved.

The invention discloses a flexible-magnet-based electromagnetic surface acoustic wave transducer, and belongs to the field of electromagnetic ultrasonic nondestructive detection. The transducer comprises a flexible magnet and a flexible cambered meandered coil. Compared with a rigid magnet, the flexible magnet is flexible and can be bent into a certain angle to be attached to a steel rail, so that the transducer is unlikely to be abraded when being used. When the cambered meandered coil is charged with alternating current, eddy current is generated on the surface of a test piece, and a surface wave signal is generated in the steel rail on the basis of the principle of Lorentz force under the action of a bias magnetostatic field provided by the flexible magnet. The flexible cambered meandered coil has a convex direction and a concave direction, the convex and concave directions of the flexible cambered meandered coil are selected by taking a required signal propagation direction as a reference to focus the energy of the generated surface wave signal towards a direction, and signal propagation unidirectionality is verified by experiments.

The invention discloses a method for producing a sapphire surface acoustic wave transducer, belongs to the technical field of manufacture of surface acoustic wave devices. The method comprises the following steps of: firstly lithographing and developing a graph of the surface acoustic wave transducer on the surface of a sapphire, and then adopting the ion injection method to inject metal aluminum or copper element; then depositing a polycrystalline aluminum nitride piezoelectric thin film on the surface of the sapphire after ion injection; and finally removing a photoresist and obtaining the graph of the surface acoustic wave transducer. The method greatly reduces the surface resistivity of the sapphire by injecting the ions and greatly enhances the electric conductivity, thereby replacing the original deposition of a conductive thin film. The method does not need to deposit an Al or Au thin film and does not need the etching process either. Therefore, the operation is greatly simplified, and the anti-power bearing force of the device is also greatly enhanced.

The invention discloses an application circuit of a surface acoustic wave transducer. The application circuit comprises a first surface acoustic wave oscillator circuit, a second surface acoustic wave oscillator circuit, a mixer circuit and an LC passive low-pass filter circuit, wherein the output end of the first surface acoustic wave oscillator circuit and the output end of the second surface acoustic wave oscillator circuit are connected with the input end of the mixer circuit respectively, and the output end of the mixer circuit is connected with the input end of the LC passive low-pass filter circuit. According to the application circuit, a three-point capacitive negative feedback element is adopted as a frequency selection and feedback network, the feedback voltage of the capacitive negative feedback element is tapped from the two ends of a capacitor, higher harmonics can be effectively filtered out with small impedance, and stable waveform output is achieved; a high-frequency low-power tube amplifying circuit is a bias-emitter common-collector amplifying circuit, persistent oscillation is achieved, and therefore oscillation signals are more stable; two surface acoustic wave oscillators form a two-channel structure, interference caused by the external environment is avoided, and high-precision measurement of physical quantities to be measured is achieved.

The invention discloses a preparation method of a surface acoustic wave transducer with a temperature compensation function, and relates to the field of surface acoustic wave device manufacturing, and the method comprises the steps: preparing an interdigital transducer on a piezoelectric substrate, wherein the interdigital transducer comprises a first interdigital structure and a second interdigital structure which are oppositely crossed, the two interdigital structures are the same and each comprise a first-type interdigital electrode and a second-type interdigital electrode serving as a sacrificial layer; preparing a first temperature compensation dielectric film on a piezoelectric substrate, wherein the profile morphology of the first temperature compensation dielectric film has the characteristics that the upper part of an electrode protrudes and the upper part of a gap between adjacent electrode fingers is flat; reducing the film thickness of the first temperature compensation dielectric film to be close to the thickness of the first-type interdigital electrode to form a first temperature compensation dielectric layer; corroding and stripping the sacrificial layer; and preparing a second temperature compensation dielectric layer on the surfaces of the first-type interdigital electrode and the first temperature compensation dielectric layer. The surface appearance of the medium is controlled by using a sacrificial layer technology, and the insertion loss is reduced and the performance of the surface acoustic wave transducer is improved through the control over the double-layer medium.

The invention discloses a manufacturing method for a surface acoustic wave transducer, which belongs to the field of sensor production. The manufacturing method comprises the steps that: firstly, a titanium thin film, an aluminum and molybdenum alloy thin film, a titanium thin film, an aluminum and molybdenum alloy thin film are deposited on a piezoelectric substrate sequentially; secondly, photoresist is coated on the films and exposed to form graphics of the surface acoustic wave transducer, and a mixed gas of chlorine and boron trichloride etches away non-graphical areas that the photoresist does not cover; and finally, the photoresist is removed to obtain the graphics of the surface acoustic wave transducer. The four layers of films of the manufacturing method can inhibit the movement of aluminum atoms and improve the adhesive attraction of the films and the power-carrying capacity. The manufacturing method improves the performance of the aluminum film as well as the accuracy of the etching graphics of reactive ions, thereby improving the performance of the transducer and prolonging the service life of the device.

The present application describes embodiments of a radio-frequency identification (RFID) sensor based on a combination of a surface acoustic wave (SAW) transducer and two-dimensional electron gas (2DEG) or two-dimensional hole gas (2DHG) conducting structure, and its use in chemical detection and (bio) molecular diagnostics. The SAW RFID sensor chip contains a piezoelectric substrate, on which a multilayer heterojunction structure is deposited. The heterojunction structure comprises at least two layers, a buffer layer and a barrier layer, wherein both layers are grown from III-V single-crystalline or polycrystalline semiconductor materials, such as GaN/AlGaN. Interdigitated transducers (IDTs) transducing SAWs are installed on top of the barrier layer. A 2DEG or 2DHG conducting channel is formed at the interface between the buffer and barrier layers and provides electron or hole current in the system between the non-ohmic (capacitively-coupled) source and drain contacts connected to theformed channel.

The invention discloses an acoustic surface wave transducer with multi-order transverse mode suppression and a manufacturing method. The surface acoustic wave transducer comprises a wafer substrate, an interdigital metal layer and a temperature compensation layer which are sequentially arranged from bottom to top, the load layer adopts one of the following structures or a combination of the following structures; according to a first structure, a load layer is arranged on or in a temperature compensation layer, the load layer does not make contact with an interdigital metal layer, and the load layer covers all or part of finger strip ends in the interdigital metal layer; according to a second structure, the load layer is arranged in the wafer substrate, the load layer is located at the position corresponding to the finger strip end of the interdigital metal layer, and the load layer is made of a conductive material; and according to a third structure, the load layer is located between the interdigital metal layer and the temperature compensation layer, the load layer covers all or part of finger strip ends in the interdigital metal layer, and the load layer is made of a non-metal material. An end area of the finger strip is processed to block a transverse mode, and an electrical performance index and a quality Q value are improved; a load layer of the first structure is isolated from an interdigital metal layer through a temperature compensation layer and is not connected with the interdigital metal layer to be short-circuited.

The invention provides a surface acoustic wave transducer for detecting volatile organic pollutants. The central working frequency of the surface acoustic wave transducer is 200MHz, a lithium niobate material is adopted as a substrate, gold is adopted as an interpolation energy transducer material, and sol-gel silicon oxide is adopted as a sensitive membrane material; the effective area of a sensitive membrane is greater than 6mm<2>, and the sensitive membrane has a favorable adsorption effect on common volatile organic pollutants; after the sensitive membrane is saturated, alcohol is adopted for flushing so as to remove surface adsorption, and the sensitive membrane can be reused. The surface acoustic wave transducer for detecting volatile organic pollutants is high in measurement precision and convenient to use.

The invention discloses a method for manufacturing a surface acoustic wave transducer sensitive membrane. The method is characterized in that a sensitive membrane is formed on a delay line of a double delay line type oscillator through electron beam evaporation and photoresist stripping, wherein the sensitive membrane is a polymer sensitive membrane consisting of TiO2 and WO3. By utilizing the method provided by the invention, the TiO2 is added to the WO3 to manufacture the polymer sensitive membrane; compared with a pure WO3 transducer sensitive membrane, both the sensitivity and the detection quality of the doped WO3/TiO2 transducer sensitive membrane are improved to a certain extent, and WO3 is probably used for detecting NO2 gasat normal temperature.

The invention relates to a bridge type surface acoustic wave transducer in a micro-optical-electro-mechanical gyroscope. An embedded strip-shaped acoustic-optical waveguide region is produced on a substrate material, the bridge type surface acoustic wave transducer is further provided with a pressure welding electrode, interdigital electrodes and a bridging electrode, electrode structures of the interdigital electrodes are divided into two groups and respectively positioned on the upper side and the lower side of the acoustic-optical waveguide region with the interval of less than six sound wave wavelengths, and the two groups of the interdigital electrodes are connected through the bridging electrode and penetrate the acoustic-optical waveguide region. When a driving power supply is imposed between the upper group and the lower group of the surface acoustic wave interdigital electrodes for generating surface acoustic waves, an acoustic wave field of the acoustic-optical waveguide region and the region of the interdigital electrodes are completely uniform and consistent, thereby leading acoustic waveguide of the acoustic-optical waveguide region to have no sound field mutation. Thebridge type surface acoustic wave transducer adopts the bridging form for reducing the area of a metal electrode of acoustic-optical waveguide under the premise of keeping the acoustic wave field ofan acoustic-optical active region unchanged, thereby not only keeping the characters of the acoustic wave field, but also effectively reducing the absorption of optical waves of the metal electrode.

A substrate before an insulation process, which is provided with a protection film to prevent a part of a surface area, which has electrical conductivity from being insulated, the substrate comprises: a base including the surface area, which has electrical conductivity; a protection film covering over the part of the surface area, which has electrical conductivity, and being formed on the base; the protection film including; a first protection layer having a circumferential partition wall and a second protection layer placed and embedded in an area, which is surrounded by the circumferential partition wall.

The present invention relates to an acousto-optic device capable of extending the frequency band of SAWs being able to be generated by it, the acousto-optic device comprising: a light propagation unit for propagating light; a surface acoustic wave propagation unit capable of propagating a surface acoustic wave causing interaction with light which propagates in the light propagation unit; and a transducer electrode unit provided with a plurality of electrodes configured so as to correspond to a frequency band to be generated as the surface acoustic wave which propagates in the surface acoustic wave propagation unit.