192results about How to "Improve frequency response" patented technology

Digital filters for processing an input audio signal for extending the audio capabilities and reducing distortion of a loudspeaker. Such extension may include a general sound pressure level (SPL) extension or a more targeted low frequency (LF) extension. This may be accomplished by modifying an original frequency response of the loudspeaker to achieve a particular extension, and applying a digital linear filter based on the modified frequency response to the audio signal. A nonlinear digital filter may also be applied to the audio signal reduce nonlinear distortions of the loudspeaker. The nonlinear digital filter may be based on an inverse of an electro-mechanical model of the loudspeaker. In this manner, a loudspeaker may be driven close to its maximum theoretical power capability without increasing distortion in the loudspeaker output.

A micromachined design and method with inherent disturbance-rejection capabilities is based on increasing the degrees-of-freedom (DOF) of the oscillatory system by the use of two independently oscillating proof masses. Utilizing dynamical amplification in the 4-degrees-of-freedom system, inherent disturbance rejection is achieved, providing reduced sensitivity to structural and thermal parameter fluctuations and damping changes over the operating time of the device. In the proposed system, the first mass is forced to oscillate in the drive direction, and the response of the second mass in the orthogonal direction is sensed. The response has two resonant peaks and a flat region between peaks. Operation is in the flat region, where the gain is insensitive to frequency fluctuations. An over 15 times increase in the bandwidth of the system is achieved due to the use of the proposed architecture. In addition, the gain in the operation region has low sensitivity to damping changes. Consequently, by utilizing the disturbance-rejection capability of the dynamical system, improved robustness is achieved, which can relax tight fabrication tolerances and packaging requirements and thus result in reducing production cost of micromachined methods.

The invention discloses a voice enhancement method employing a combination of nesting-subarray-based post filtering and spectrum-subtraction and is suitable for indoor environment, comprising the enhancement of multi-channel voice signal in vehicle environment; as the problems of unstable the broadband of the voice signals, the inconsistent frequency response of the microphone-array-based multi-channel voice-enhancement method to the voice signal and the correlation among all-channel noise in actual noise-field environment are considered, by utilizing the microphone array nested by the subarrays with different spacing, the voice signals are collected; and the voice signals formed by subarray beams are divided into a high-frequency section and a low-frequency section, different voice-enhancement algorism are adopted for carrying out the treatment; all the advantages are complementary with each other, thus improving the effect of voice enhancement.

An area-efficient capacitor-free low-dropout regulator based on a current-feedback frequency compensation technique is disclosed. An implementation of a current feedback block with a single compensation capacitor is used to enable capacitance reduction. The resultant low-dropout regulator does not generally require an off-chip capacitor for stability and is particularly useful for system-on-chip applications.

A speaker apparatus for producing sound comprising of a housing, a plurality of covers, a speaker driver, a radiator, a resonator and a resonator stand which in combination provide an enhanced low frequency sound output.

A sensor unit is configured as a single body, removably mounted in its entirety to a test point location on a machine so machine vibrations propagate into the single body. Within are an accelerometer, circuit board, wireless interface, signal processor, and battery. The sensor unit transmits sensor data wirelessly in real time to a data collection unit. A technician with data collection unit in hand goes from machine to machine, along a route of multiple test point locations on multiple machines, mounting and dismounting the sensor unit and collecting machine vibration data. The sensor unit is configured to reduce frequency response impacts of the mass and volume of the circuit board, wireless interface, signal processor, and battery on dynamic behavior of the sensor unit with respect to machine vibrations to achieve a frequency response rating comparable to a wired sensor.

The present invention consists of the particular geometry of the reflectors or dispersers which constitute the anti-radar chaff cloud. Instead of using conventional rectilinear forms, in the present invention multilevel and space-filling forms are introduced. Due to this geometric design, the properties of the radar chaff clouds improve mainly in two aspects: radar cross-section (RCS) and mean time of suspension.

A safe in-ear earphone for radiation protection, comprises earplug heads (1A, 1B), sound cavities (2A, 2B), acoustic wave transmission channels (3A, 3B), a main body (4), a conductor (8) and a plug (9), the channels (3A, 3B) are set between the sound cavities (2A, 2B) and loudspeakers (5A, 5B), the acoustic wave concentrated orifices (10A, 10B) are between the loudspeakers (5A, 5B) and the acoustic wave transmission channels (3A, 3B), assembly of the loudspeakers (5A, 5B), the acoustic wave concentrated orifices (10A, 10B) and the acoustic wave transmission channels (3A, 3B) are sealed to form a sealed small boxes (11A, 11B) in the main body (4). the shape of acoustic wave concentrated orifices (10A, 10B) is inversely conical. The acoustic wave is transmitted to the two acoustic wave channels (3A, 3B) via the acoustic wave concentrated orifices (10A, 10B) and then is provided to the ears plugged by two earplugs to listen. The safe in-ear earphone is used for high frequency magnetic field and intense radiation communication device such as mobile phone.

The invention discloses an ultra-wideband high-bandwidth radio frequency two-way transceiving integrated integration module, belonging to the technical field of wireless information transmission. Themodule comprises a main control unit, a power supply unit, a microwave frequency synthesis unit, a radio frequency transmission unit, a radio frequency receiving unit, a digital signal processing unitand a radio frequency transceiving control unit, wherein the main control unit is mainly used to complete bus driving, data interaction, signal processing and other functions; the power supply unit is used to provide a high-stability and low-noise power supply; the microwave frequency synthesis unit, the radio frequency transmission unit, the radio frequency receiving unit and the digital signalprocessing unit adopt a microwave frequency synthesis technology, a wideband frequency conversion technology, a signal conditioning technology, a wideband modulation and demodulation technology and adigital signal processing technology to achieve the maximum one-way 8*8 or two-way 4*4 radio frequency transceiving; and the radio frequency transceiving control unit is used to achieve radio frequency transceiving control. The radio frequency two-way transceiving integrated integration module disclosed by the invention is easy to integrate, can be expanded, and can meet the requirements of large-scale MIMO radio frequency multi-channel transceiving.

The invention relates to a hydroacoustic transducer, in particular to a micro-electromechanical vector hydrophone which solves the problem that the enhancement of the overall performance is affected by the encapsulating structure of the existing vector hydrophone. The micro-electromechanical vector hydrophone comprises a sensitivity-conversion micro-structure, a support for fixing the sensitivity-conversion micro-structure, and an encapsulating housing covering the sensitivity-conversion micro-structure and hermetically fixing the support, wherein, the sensitivity-conversion micro-structure comprises a cross-shaped cantilever beam structure and a miniature cylindrical body vertically fixed in the center of the cross-shaped cantilever beam structure; conversion elements are arranged at the ends of the four beams of the cross-shaped cantilever beam structure; the encapsulating housing is a sound-transparent rubber cap made of polyurethane encapsulating materials; and polyurethane for fixing the top end of the miniature cylindrical body and the sound-transparent rubber cap is encapsulated at the top of the sound-transparent rubber cap. The invention increases the sensitivity of the hydrophone, improves the frequency response thereof and ensures the high signal-to-noise ratio at low frequencies by improving the encapsulating structure and replacing the conversion elements of the sensitivity-conversion structure, so that the hydrophone can show excellent performance.

There is provided a variable directional microphone including dynamic microphone units that is small in size and has good directional frequency response. In a variable directional microphone 1A in which a unidirectional first dynamic microphone unit (front-side unit) 1F and a second dynamic microphone unit (rear-side unit) 1R, which has substantially the same configuration as that of the front-side unit 1F and is provided with an output adjusting means of sound signal, are provided as a pair; the front-side unit 1F and the rear-side unit 1R are arranged coaxially so that the directivity axes thereof are directed to the directions 180° opposite to each other; and the output signals of the front-side unit 1F and the rear-side unit 1R are generated via a signal synthesis circuit, one rear air chamber 1b is used in common by the front-side unit 1F and the rear-side unit 1R.

Band reject filters are disclosed. A band reject filter includes a first acoustic resonator and a second acoustic resonator, each of which has either shunt resonators adapted to resonate substantially at respective resonance frequencies defining a rejection frequency band or series resonators adapted to anti-resonate substantially at respective anti-resonance frequencies defining the rejection frequency band. These resonators are connected through a phase shifter which imparts an impedance phase shift of approximately 45° to 135°. Exemplary applications of the band reject filters disclosed herein include implementation as an inter-stage band reject filter for a base station power amplifier for a wireless communication system, as a radio frequency band reject filter in a duplexer for a wireless communication terminal, and in a low noise amplifier input stage.

In electrostatic inkjet recording in which an ink droplet is ejected by acting electrostatic force on ink that contains colorant particles, the electric conductivity of the colorant particles in the ink is saturated. Thus, variations in ink dot diameter caused by the ejection delay and a decrease in frequency responsivity are avoided, so that high-quality image recording with good frequency responsivity can be realized.

The invention relates to an optical fiber vibrating sensor and a power transmission line aeolian vibration monitoring system applying the same. The optical fiber vibrating sensor comprises a fixed body, a constant-strength beam and a contact body arranged on a lead wire, wherein the fixed body, the constant-strength beam and the contact body are connected in sequence. The fixed body is connected with the lead wire through a clamp arranged on the lead wire, and the upper and lower surfaces perpendicular to the axis of the constant-strength beam are symmetrically provided with fiber bragg gratings. The sensor is installed by adopting an upright method of hull section construction, and an installing point is a fatigue dangerous point of a ground conductive wire. The monitoring system comprises the optical fiber vibrating sensor, an optical fiber composite overhead ground wire, a wave-length adjusting device and a host machine which are connected in sequence. The sensor and the monitoring system have the advantages of being high in measuring accuracy, high in speed, good in frequency response, stable in long-term performance and the like, the problem that the prior art susceptible to influence of complicated electromagnetic environment, measuring accuracy, poor flexible, large size and poor system stability, cannot achieve field information transfer in real time and the like is solved, and the stability and reliability of the system are improved.

An electroacoustic transducer includes a driver, a diaphragm 13 driven to vibrate by the driver and emitting sound, a baffle 22 holding the driver and the diaphragm 13, first openings 25 extending through the baffle 22, an acoustic resistor 23 disposed on the back side of the baffle 22, and second openings 26 extending from the front side to the back side of the acoustic resistor 23. The baffle 22 is provided on the back side of the diaphragm 13. The first openings 25 are provided in the baffle 22. The second openings 26 are each disposed above one of the first openings 25 in the acoustic resistor 23. The electroacoustic transducer exhibits an excellent frequency response even if a sufficient volume of a space is not provided on the back side of the diaphragm 13.

The invention discloses a sensor installing device which comprises an installing seat (2) for fixing a sensor (1). The sensor installing device further comprises a permanent magnetic sucker (3) for fixing the installing seat (2). Due to the technical scheme, when the sensor installing device is in use, magnetism of the permanent magnetic sucker is closed first, the permanent magnetic sucker is attached to a measured structure, then the magnetism of the permanent magnetic sucker is opened, and the sensor can be firmly installed on the measured structure. After the sensor installing device is used, users only need to close the magnetism of the permanent magnetic sucker, and the sensor can be dismantled easily. Therefore, the sensor installing device has the advantages of being good in universality, firm to install, good in frequency response performance and easy to dismantle and avoiding causing damage to the measured structure and the like.

Circuits and methods for compensating for an input-dependent gain error in a buffer and/or amplifier circuit, including applying a dynamic current to the input transistor. Circuits generally include a dynamic current supply coupled to a terminal of the input transistor, the dynamic current supply providing a compensating current. The compensating current can have a magnitude equal to the output impedance of the input transistor times a magnitude of the output voltage. The compensating current can be provided via a current mirror, or directly to a terminal of the input transistor. Methods generally include regulating variations in the current through the input transistor by sinking or sourcing a static current and a dynamic current at a terminal of the input transistor. The dynamic current can be regulated in response to a variation in the input signal.

The invention provides a non-load-sharing piezoelectric thrust test device, belongs to the technical field of sensors and measuring and control technology, and particularly relates to the test technology of the pulse thrust of attitude control rocket engine. The test device comprises an outer shell, an inner shell, four piezoelectric quartz sensors, four square press plates, four support rods, an engine installation flange, pre-fastening bolts and connection bolts. Piezoelectric quartz sensors made of four YO cut type quartz chip resemble a diamond shape and are located between the inner shell and the outer shell. Four pre-fastening bolts and square press plates are used for pressing all the piezoelectric quartz sensors tightly. Rocket thrust force generated by fuel ejection is transmitted to the piezoelectric sensors through the installation flange, the four support rods and the inner shell, thus eliminating the load division phenomenon in the traditional piezoelectric test system caused by bolts connection or an elastic ring clamping which are adopted by the piezoelectric quartz sensors for pre-fastening, and enhancing the sensitivity and the dynamic measurement accuracy of the test system. The device has the advantages of having high sensitivity, good frequency response performance, being high in dynamic measurement accuracy, therefore can be adopted for testing the pulse thrust of the attitude control rocket engine.

A digitally controllable resistor includes a substrate and at least one digitally controllable resistance stage formed on the substrate. Each of the stage(s) can include a first resistor connected inseries with a switch and a second resistor connected in parallel with the first resistor and the switch. Each stage can also include a control line connected to the switch for opening and closing theswitch in response to a control bit associated therewith. Multiple resistance stages can be connected in series and the digitally controllable variable resistor can be integrated onto a substrate.