40results about How to "Reduce frequency difference" patented technology

An ion trap includes an electrode structure, including a first and a second opposed mirror electrodes and a central lens therebetween, that produces an electrostatic potential in which ions are confined to trajectories at natural oscillation frequencies, the confining potential being anharmonic. The ion trap also includes an AC excitation source having an excitation frequency f that excites confined ions at a frequency of about twice the natural oscillation frequency of the ions, the AC excitation frequency source preferably being connected to the central lens. In one embodiment, the ion trap includes a scan control that mass selectively reduces a frequency difference between the AC excitation frequency and about twice the natural oscillation frequency of the ions.

A clock recovery circuit through NFC active load modulation based on a digital phase-locked loop is formed by a digital phase-locked loop and a digital delay locking loop. The digital phase-locked loop works under a tracking carrier frequency mode and a fixed oscillation frequency mode. Under the fixed oscillation frequency mode, oscillation frequency is formed and locked in the period of tracking a carrier wave, the digital phase-locked loop is an all-digital structure phase-locked loop, and the digital delay locking loop receives a split phase clock of the phase-locked loop, and fast locks a clock which is closest to a carrier phase through comparison with a phase of the carrier wave. The digital delay locking loop works under a phase tracking mode and a fixed phase mode, under the fixed phase mode, the digital delay locking loop constantly outputs the same split phase clock, and the clock is obtained under a tracking mode. The clock recovery circuit reduces frequency difference caused by injecting noise in the time of conversion from a closed loop to an open loop, enables bandwidth of the phase-locked loop to be reduced to further lower phase noise, and can avoid the situation that the phase difference cannot be corrected due to the fact that the bandwidth is reduced.

A surface acoustic wave device, includes: an interdigital transducer serving as an electrode pattern to excite a Rayleigh surface acoustic wave, the interdigital transducer including a comb-tooth-shaped electrode having a plurality of electrode fingers; a piezoelectric substrate on which the interdigital transducer is formed, the piezoelectric substrate being made of a quartz substrate that is cut out at a cut angle represented by an Euler angle representation (φ, θ, Ψ) of (0°, 95°≦θ≦155°, 33°≦|Ψ|≦46°); electrode finger grooves formed between the electrode fingers of the comb-tooth-shaped electrode; and electrode finger bases being quartz portions sandwiched between the electrode finger grooves and having upper surfaces on which the electrode fingers are positioned The surface acoustic wave device provides an excitation in an upper limit mode of a stop band of the surface acoustic wave.

A surface acoustic wave device includes a piezoelectric substrate having a first surface on which comb-like electrodes are formed, and a second surface, and a support substrate joined to the second surface of the piezoelectric substrate. The piezoelectric substrate is made of lithium, tantalate, and the support substrate is made of sapphire. The following expressions being satisfied:

T/t<⅓  (1)

T/λ>10  (2)

where T is a thickness of the piezoelectric substrate, t is a thickness of the support substrate, and λ is a wavelength of a surface acoustic filter, propagated along the first surface of the piezoelectric substrate.

The invention relates to the field of coalfield geophysical prospecting, and discloses a three-dimensional seismic data processing method and system. The three-dimensional seismic data processing method comprises the steps that three-dimensional seismic data are processed in a coordinated by using multiple static correction methods so that the weak reflection signals of the three-dimensional seismic data are enabled to be superposed in an in-phase way; and/or surface wave suppression is performed on the three-dimensional seismic data after static correction by using three-dimensional conical filtering based on a frequency-wavenumber domain. The imaging problem of the shallow depth coal seam can be effectively solved by the three-dimensional seismic data processing method and system.

A frequency tracking circuit is disclosed. The frequency tracking circuit includes an edge selector, a phase-frequency processor and a digital controlled oscillator. The edge selector receives a data signal and feedback clock signal and sequentially outputs a data edge signal and a feedback-clock-edge signal. The phase-frequency processor receives the data edge signal and the feedback-clock-edge signal and outputs a frequency adjusting digital signal after executing differential operation according to a first phase difference and a second phase difference. The digital controlled oscillator receives the frequency adjusting digital signal so as to adjust frequency of the feedback clock signal. The phase-frequency processor outputs a frequency tracking signal to the edge selector, wherein the edge selector utilizes the frequency tracking signal for acquiring the data edge signal and utilizes the data edge signal for acquiring the feedback-clock-edge signal.

The invention discloses a regular dodecagonal annular resonant micro-mechanical gyroscope structure, and belongs to the field of micro-sensors. According to the regular dodecagonal annular resonant micro-mechanical gyroscope structure, the advantages of an annular resonant gyroscope are completely reserved, and the problems that the resonance frequency of the annular gyroscope is relatively high and deviation angles between a main damping direction in a working mode that n is equal to 3, and driving and sensitive axes are relatively large are solved; and meanwhile, the detection capacitance isexpanded, so that the sensitivity can be improved. The gyroscope structure sequentially comprises a base silicon body, an anchor point and a device layer; the gyroscope structure is characterized inthat the device layer comprises a regular dodecagonal annular structure, spokes, a center support and electrodes; and the device layer is suspended on the base silicon body through the center support.

An ultrasound sensor includes: a diaphragm; a plurality of first electrodes; a plurality of second electrodes; and a plurality of piezoelectric layers which is provided between the first electrode and the second electrode, in which, in a Z-direction, a portion in which the first electrode, the piezoelectric layer and the second electrode are overlapped is referred to as an active portion, and a range to the extent that the diaphragm is oscillatable by driving the active portion is referred to as a movable portion, when a unit including one movable portion and the active portion which is provided within the one movable portion is referred to as one ultrasound element in plan view, two or more types of ultrasound elements in which a dimension of the active portion with respect to a dimension of the movable portion is different from each other in plan view are provided.

An audio and video communications apparatus eliminates a system clock frequency difference, freeing a user from unconformable feeling of audio and video. The audio and video communications apparatus includes: a transmitting unit and a receiving unit (106/108) transmitting and receiving audio and video via a network; a PTS correction timing determining unit (111) determining timing to update a correction amount of a PTS according to information of the audio or the video to be transmitted and received, the PTS being given to the received audio or the received video; a PTS correcting unit (112) correcting the PTS by updating the correction amount at the timing determined by the PTS correction timing determining unit (111); and an audio and video output unit (113) outputting the received audio and the received video corresponding to the corrected PTS found at a current time indicated by the audio and video communications apparatus.

The invention relates to a frequency control circuit and an ultrasonic transducer system. A first signal processing module is used for outputting a first to-be-detected signal through a signal collected by a voltage collecting module; a second signal processing module is used for outputting a second to-be-detected signal through electric current collected by an electric current module; according to the output detection results of the first to-be-detected signal and the second to-be-detected signal, a phase detection module enables a processor to change the frequency of a stimulus signal in a stimulus signal source according to the detection results; and the phase of the first to-be-detected signal is the same as the phase of the voltage, and the phase of the second to-be-detected signal isthe same as the phase of the electric current, so that the detection results are related to the phase of the voltage and the phase of the electric current. When the voltage is ahead of the electric current or the electric current is ahead of the voltage, the frequency of the stimulus signal is changed according to the corresponding detection results, so that the difference between a natural frequency and the frequency of the stimulus signal is reduced, and it is ensured that an ultrasonic transducer works under a working condition with the highest efficiency.

A frequency adjustment method of a piezoelectric resonance component. When an energy beam is irradiated from above to etch the electrodes to adjust the frequency, it is difficult to cause a decrease in insulation resistance, short-circuit defects, and migration between electrodes. It has a piezoelectric body (14) with side surfaces (14a, 14b) and an upper surface, and an electrode (15) designed on the piezoelectric body. A piezoelectric resonance member having side surfaces (14a, 14b) as inclined surfaces so that the lower portion is located on the center side of the piezoelectric body (14) than the upper end. A frequency adjustment method in which a shield layer (22) including an opening (22a) is arranged on the upper surface of the piezoelectric resonant member, and the frequency is adjusted by irradiating an ion beam from above.

Methods and a receiver of positioning a spurious signal for reducing the impact of the spurious signal on a received Orthogonal Frequency Division Multiplexing, OFDM signal, are presented. The method comprises determining the frequency of a spurious signal (steps 102, 204, 404), determining the frequency for the respective sub-carrier of the OFDM signal and the difference between the frequency of a sub-carrier and the frequency of a spurious signal (steps 104, 206, 406), and adjusting at least one of: the frequency of the first oscillator (step 208) and a parameter related to the frequency of a second oscillator, to decrease the frequency difference between a sub-carrier and a spurious signal (steps 106, 212, 408). By positioning a spurious signal at or near a sub-carrier frequency, the performance impact of the spurious signal is reduced, and the receiver performance improved.

A frequency discriminating method for AFC circuit in diversity mode includes such steps as deleting the head data of a first frame, filling zero to frame head and tail to generate continuous frequency difference detecting pairs, cross-multiplying the input signals of cross-multiplier, sending the said detecting pairs to the frequency discriminator to obtain frequency difference, and over sampling to obtain 2x samples for output. Its advantages are simple equipment and high speed.

The invention relates to a voltage-controlled active crystal oscillator control device, a voltage-controlled active crystal oscillator control method and a stage moving head lamp. The voltage-controlled active crystal oscillator control device comprises a controller and a voltage adjusting circuit. The controller is used for receiving a user instruction and generating a voltage regulation parameter according to the user instruction, and the user instruction is input by a user based on frequency offset between the output frequency of the voltage-controlled active crystal oscillator and the nominal frequency of the voltage-controlled active crystal oscillator; the voltage adjusting circuit is electrically connected with the controller, and used for receiving the voltage regulation parameter,regulating a driving voltage according to the voltage regulation parameter and providing the regulated driving voltage for the voltage-controlled active crystal oscillator, so that the frequency offset of the output frequency and the nominal frequency is within a preset range, and the problem of desynchrony caused by different output frequencies of the crystal oscillator is solved.

The invention discloses a wavelet-based multi-scale decomposition method. The method comprises the following steps: (1) storing point cloud data as 2.5 D; (2) filtering is carried out in a wavelet mode, and high frequency and low frequency are separated; (3) projecting the 2.5 D image to a scale function and a wavelet function; (4) carrying out low-pass filtering, representing the frequency image by using the wavelet in the step (3), and taking out the projections of the two parts on a scale function, namely low-frequency data of the image; (5) through filtering in the step (4), reserving low frequency, performing projection on the inverse transformation kernel through reserved low-frequency signals, and performing image reconstruction; (6) reducing the difference in a down-sampling and up-sampling mode through a pyramid method; and (7) repeating the steps (3)-(6) until the resolution of the microscopic measurement data is reduced to the specified requirement. According to the invention, the difference between the microscopic measurement data volume and the structured light measurement data volume can be reduced.

The invention discloses a high-horsepower engine gear chamber cover and an outer frame assembly. The cover comprises a combined support and a high-strength gear chamber cover body. The left side of anupper half chamber of the high-strength gear chamber cover body is designed to be sunken towards the middle portion relative to the left side of a lower half chamber. A near-rectangular tightening face is arranged on the left side of a rear chamber of the lower half chamber. A stable tightening supporting rib is arranged on the right middle portion of the rear chamber of the lower half chamber inthe longitudinal direction. The combined support is combined with the upper left portion of the upper half chamber. The combined support comprises a turbine rear exhaust connecting pipe support and arear exhaust pipe main support. The cover has the advantages of being good in anti-seismic performance, high in reliability and good in use effect.