89results about How to "Improve high frequency response" patented technology

Systems and methods for detecting the impedance of an output load coupled to a digital amplifier and compensating for changes in the response of the amplifier. One embodiment of the invention is implemented in a Class D pulse width modulated (PWM) amplifier. In this embodiment, a digital PCM test signal is generated. This test signal is processed by the amplifier to produce a corresponding analog audio output signal that is used to drive a speaker. A sense resistor placed in series with the speaker is used to generate a test voltage that is compared to a reference voltage. When the test voltage reaches the reference voltage, the current through the sense resistor (hence the speaker) is at a known level, so the value of the digital test signal is noted. The impedance of the speaker is then determined from the test signal value and the speaker current.

A VCSEL array device formed of a monolithic array of VCSELs and short circuited mesas is disclosed. The VCSELs can be spaced symmetrically or asymmetrical, in a manner to improve power or speed, or in phase and in parallel. The VCSELs are connected to a first metal contact pad formed on a heat-spreading substrate. The short-circuited mesas are formed alongside the VCSELs and are bonded to and form a short circuit to a second metal contact pad on the grounding substrate. Each VCSEL is encompassed by a thick metal heat sink to increase the height of VCSEL mesas. The structure of the heat sink, the VCSELs and the shorting mesas reduce parasitic impedance thereby increasing output power and high frequency response. The VCSELs and shorting mesas can be packaged as a coplanar waveguide in a ground-signal-ground configuration that improves signal modulation characteristics.

A multi-wire wire-bonding structure suitable for a high frequency signal comprises a first electronic device, a second electronic device, a chip pad and a plurality of metal wires. The first electronic device is attached to the second electronic device with the chip pad. As a result, the first electronic device and the second electronic device form a stair-like structure. A plurality of bonding pads comprises at least one signal bonding pad and grounded bonding pads. The signal bonding surface is surrounded by the ground bonding pads. All the bonding pads are located at the surface of the first electronic device. The chip pad carries the first electronic device and the exceeding part is a ring grounded bonding pad which surrounds the first electronic device. The second electronic device carries the chip pad and a margin of the second electronic device is exceeding the chip pad. There are several leads on the margin of the second electronic device in corresponding to the ground bonding pads and the signal bonding pad. Metal wires comprise a signal wire and grounding wires. The bonding pads of the first electronic device are classified as the first row bonding pads which is close to the ring ground bonding surface and the second row bonding pads which is away from the ring ground bonding surface. The signal wire electrically connects to the signal bonding pads and the corresponding lead. The ground wires electrically connect to the first row bonding pads and the ring ground bonding surface.

A ultrasonic probe formed by arranging a plurality of ultrasonic vibrators each including a piezoelectric layer (2) and a pair of electrodes (7-1, 7-2) provided to sandwich this piezoelectric layer, the piezoelectric layer (2) consisting of a first piezoelectric layer (2-1) disposed on the ultrasonic wave outputting side across a common electrode (8) and a second piezoelectric layer (2-2) disposed on the opposite side, each ultrasonic vibrator having a uniform low-frequency response distribution in a minor-axis direction perpendicular to the arranging direction of the ultrasonic vibrators and having a high high-frequency response distribution at the center in the minor-axis direction, characterized in that the characteristics of the minor-axis-direction frequency and sound pressure of the first piezoelectric layer are complemented by those of the second piezoelectric layer to thereby make uniform frequency characteristics for a minor-axis-direction low frequency.

The soft magnetic thin film has high saturation magnetic flux density and good soft magnetic characteristics. The soft magnetic thin film of the present invention is formed by electrolytic plating. The plated film is made of FeCo, whose composition is indicated as FexCo1-x (60≦x≦75 wt %), the FeCo film has a bcc crystal structure, and the crystal of the FeCo film is oriented to a crystal face of (110).

A multilayer structure including a first electron supply layer and a second electron supply layer is used for an electron supply layer. A multilayer structure including an SiN film and an SiO₂ film is used for an insulating film to be formed on the surface of a semiconductor. In forming an opening for exposing the electron supply layer in the insulating film, the SiN film that is in contact with the semiconductor is side-etched. Accordingly, it is possible to avoid a contact between a gate electrode and a portion, which is located on the side of the electron supply layer, of the inner peripheral surface of the opening, and further to expose only the second electron supply layer in the vicinity of the gate electrode.

The invention provides a direct drive global roof type loudspeaker, which includes a loudspeaker magnetic circuit structure which could generate a circle belt shaped radial permanent magnetic field, and a convex global roof shaped sound film and a corrugated rim connected therewith. The invention is characterized in that a wire-wound speech coil is directly formed on the sound film surface which is on the connection of the sound film global roof and the corrugated rim. Technically the speech coil is a lead for coating the insulating layer, and the speech coil can be directly coiled on the connection, or a pre-coiled coil which is directly fixed on the connection. Particularly, when the chose sound film is a textile sound film, the coil could be a lead for coating the insulating layer, which is weaved on the connection in the mode similar to sewing, thereby strengthening the integration of the sound film and the speech coil. The loudspeaker has the advantages of flat membrane type direct drive wide frequency response, free material-choosing of the global roof type sound film, graceful timbre, and wire-wound speech coil with small volume, high efficiency and uniform magnetic field or the like.

The present invention discloses a positioning device and positioning method of a partial discharge source of an electrical device. The positioning device comprises a pressure differential vector sensor, a high-frequency carrier communication module and an analysis device. The pressure differential vector sensor is arranged in the insulating oil of the electrical device and configured to collect discharge information; the high-frequency carrier communication module is configured to send the transmission information of the pressure differential vector sensor to the analysis device; and the analysis device is arranged in a control chamber and configured to perform analysis of information collected by the pressure differential vector sensor to obtain the concrete position of the partial discharge source. The positioning device and positioning method of a partial discharge source of an electrical device are used for positioning the partial discharge source in the insulating oil of the electrical device, with simple structure, convenient usage and accurate positioning.

A photocurable composition includes an acid-generating compound, a multifunctional epoxy resin, and an epoxysilane oligomer represented by the following Structure (I):

wherein R₁ is a substituted or unsubstituted alkyl group, R₂ is a substituted or unsubstituted linear, branched, or cyclic alkyl group or an alkyl ether residue substituted with an epoxide, R₃ is hydrogen or a substituted or unsubstituted alkyl, and x+y≧2. The photocurable composition can be provided as a photoresist layer on a substrate, and can then be imprinted to form a pattern of micro-channels. These micro-channels can be filled with a conductive composition (ink) and used to form an entrenched pattern of micro-wires to provide a transparent conductive electrode.

The invention discloses an in-well seismic data acquisition device and acquisition method based on an MEMS optical fiber detector, and the device comprises a ground artificial seismic source and a plurality of in-well three-component optical fiber seismic signal receiving and acquisition short circuits which are connected with a ground composite modulation and demodulation instrument through armored photoelectric composite cables. The armored photoelectric composite cable controls the depth position of the three-component optical fiber seismic signal receiving and collecting pup joint in the well and synchronously collects DASVSP data; a three-component optical fiber seismic signal sensor module and a three-component optical fiber attitude sensor are installed in each in-well three-component optical fiber seismic signal receiving and acquisition short circuit. The device is high in sensitivity, the acquisition device is very simple, the acquisition device descends into all high-temperature wells to acquire three-component seismic data or micro-seismic data in the high-quality wells, DAS-VSP data of the whole well section above a detector are synchronously acquired, and powerful technical support is provided for application of the oil reservoir geophysical technology.

The hook shockproof hammer of the invention relates to a protecting tool which absorbs the vibration energy of the aerial cable, and is especially suitable for the hook shockproof hammer used by the optical cable circuit. The structure of the hook shockproof hammer comprises a hook, a pre-twisted wire, a steel twisted wire, a bug hammerhead and a small hammerhead; the hook body at the upper part of the hook is sleeved on the cable, the upper part of the hook body of the hook is arranged with a through hole, the pre-twisted wire traverses the through hole at the upper part of the hook and is permanent-connected with the cable; the lower part of the hook is arranged with a through hole, the middle part of steel twisted wire is fixed in the through hole at the lower part of the hook, the two ends of the steel twisted wire respectively extend into the inner bottom of the large and small hammerheads and are permanent-connected with the connecting glue. The protecting tool of the invention has the advantages of being able to reduce the problem of large compression stress of the shockproof hammer to part of the cable, changing the rigid connection of the bolt connection to a flexible connection, strengthening the self-damping of the cable, effectively preventing the phenomenon of the shockproof hammer sliding because of the loosening of the screw, broader covering area of the frequency, better high-frequency response, being able to satisfy the special shock-proof request to power thereby ensuring the safe operation of the circuit.

The present invention provides a probe block, which comprises 1) a conductive base on which a first groove is formed, 2) a pair of signal transmitting probes which have dielectric covers and are placed parallel to each other in the first groove, and 3) a ground probe which is in contact with the conductive base, wherein front portions of the signal transmitting probes and the ground probe protrude from the conductive base to form signal transmitting probe needles and a ground probe needle, respectively. The probe block of the present invention has excellent high frequency responses characteristics and is easy for maintenance.

The invention discloses a laser gyro shaking stripping device which is used for adaptively stripping a laser gyroscope shaking signal by adopting an LMS (Least Mean Square) algorithm based on an adaptive compensation technology. The sampling frequency of the stripping device is integral multiples of shaking frequency. A sine and a cosine reference signals for stripping are obtained by using one path of sampling differential signals through simple and digital delay, system input and output response is unchangeable when approximating, and thus shaking stripping effect can be improved.

A method of modulating an optical signal passing through a waveguide structure with a plurality of sections including electrically biasing one or more of the sections with a bias voltage to achieve a predetermined level of chirp, modulation depth, or insertion loss. Preferably, two or more sections are biased with a reverse bias voltage, a zero bias voltage, or forward bias voltage.

The invention relates to an earthquake simulation vibrostand control method, which belongs to the technical field of structural experiment. According to the control method, a differential signal of anacceleration instruction signal and a differential signal of an acceleration feedback signal are obtained by virtue of differentiation, a difference between the displacement feedforward and feedbackis integrated to obtain a displacement error integral signal, summation is performed for the acceleration instruction differential signal, the acceleration feedback differential signal and the displacement error integral signal and the known three parameter instruction signal, thereby obtaining a composite multi-parameter control signal. Compared with the existing three-parameter control method, the acceleration feedback differential signal in the multi-parameter control algorithm can reduce the influence of system resonance frequency and can increase the system bandwidth; the acceleration instruction differential signal can increase the system frequency band and can improve the system high-frequency performance; and the displacement error integral signal can reduce a displacement static error of a multi-vibrostand system and can improve the low-frequency control performance of the system.

The invention relates to a submarine optical fiber four-component seismic instrument system and a data acquisition method thereof. Four-component node seismic instruments are connected in series to an armored photoelectric composite cable at certain intervals through a circular cable ring; the armored photoelectric composite cable is connected with a computer; an external close-range wireless transmission module, an external photoelectric conversion module and an external wireless charging module are arranged on the side face of each four-component node seismic instrument in a matched mode, and all the modules are fixed to the armored photoelectric composite cable through functional module sleeves; and the four-component node seismic instruments are connected with the computer through the external close-range wireless transmission modules and carries out communication and data transmission. The system has the advantages of high sensitivity, wide frequency band, good high-frequency response, flat frequency characteristic response, linear phase change and good technical parameter consistency; and since no electronic element is arranged at the front end, the device has the advantages of higher reliability, resistance to high temperature and high voltage, no need of power supply, water resistance, corrosion resistance, capability of being arranged for a long time, electromagnetic interference resistance and small channel cross-talk.

A semiconductor laser device includes a first semiconductor stack portion that includes a grating layer and an active layer provided on the grating layer. The grating layer has a first region and second region; a diffraction grating provided in the first region; a semiconductor ridge structure portion provided on the first semiconductor stack portion and extending in a first direction; and a pair of first trenches provided along both side faces of the semiconductor ridge structure portion with the first region of the grating layer being located between the trenches. The first trenches penetrate through the grating layer. The first region of the grating layer has an end extending in a second direction intersecting with the first direction. The end of the first region of the grating layer reaches a trench.

The invention discloses an array type in-well four-component optical fiber seismic data acquisition device and a data acquisition method. The system comprises a ground artificial seismic source and aplurality of in-well four-component optical fiber seismic signal receiving and acquiring short circuits, and the in-well four-component optical fiber seismic signal receiving and acquiring short circuits are connected with a data acquisition control and modulation-demodulation instrument through armored photoelectric composite cables; a four-component optical fiber seismic signal sensing unit, a three-component optical fiber attitude sensor and an optical fiber inertial navigation gyroscope are arranged in each well four-component optical fiber seismic signal receiving and acquiring short circuit. According to the invention, a high-temperature-resistant three-component optical fiber detector and an optical fiber hydrophone are adopted underground; the frequency band range is larger than the frequency band response of the seismic signals in the well, the sensitivity is high, the underground four-component optical fiber seismic data acquisition device is very simple, the acquisition device can go down to all high-temperature wells to acquire the seismic data in the well, and powerful technical support is provided for efficient development of oil and gas fields.

A microphone includes a polar piece contacting with a first magnetic pole of a first permanent magnet, a yoke body annularly arranged around the polar piece through a magnetic gap G with a predetermined width, a magnetic circuit unit including a tail yoke connected to the yoke body and contacting with a second magnetic pole of the first permanent magnet, and a diaphragm unit provided with a voice coil arranged to vibrate in the magnetic gap. The second magnetic pole of the first permanent magnet contacts with one side of the tail yoke, a first magnetic pole of the second permanent magnet is disposed to contact with other side of the tail yoke, a magnetic path is produced between the second magnetic pole of the second permanent magnet and the yoke body, and the first permanent magnet and the second permanent magnet are polarized in the same sense.