46results about How to "Good low frequency" patented technology

The invention relates to an air gun array earthquake source three-dimensional space combination method for offshore earthquake exploration. The method comprises the steps of determining the total capacity of an air gun array earthquake source, and the number of subarraies, determining the capacity of each subarray and the capacity of each subarray unit in each subarray, determining the relative positions of large capacity air guns and small capacity air guns, determining the positions of all the subarraies in an air gun array, determining the optimal immersing depth of the air gun array, selecting air gun array plane arrangement parameters corresponding to simulating wavelets meeting exploration requirements, determining the optimal three-dimensional space combination mode of the air gun array and related parameters of the immersing depth of upper sources and the lower sources and the like, so that a delayed simulating three-dimensional space combination stereoscopic air gun array earthquake source can be obtained, and the delayed simulating three-dimensional space combination stereoscopic air gun array earthquake source is final air gun earthquake source three-dimensional space combination for offshore earthquake exploration. The air gun combination arrangement mode designed through the air gun array earthquake source three-dimensional space combination method is distinct in gradation, the optimal air gun combination arrangement mode is provided for different construction conditions and different offshore exploration environments, and therefore optimal far field wavelets in the current environment can be obtained. The air gun array earthquake source three-dimensional space combination method for the offshore earthquake exploration can be directly used in the outdoor offshore earthquake exploration process.

The invention provides a system and method for improving the voice quality of a mobile terminal in a receiver mode. The system for improving the voice quality of the mobile terminal in the receiver mode comprises a first signal channel and a second signal channel which are arranged in parallel; the first signal channel comprises a first power amplifier and a receiver which are electrically connected; the second signal channel comprises a second power amplifier and a vibration motor which are electrically connected; the receiver and the vibration motor simultaneously receive and play voice signals; the first power amplifier and the second power amplifier are respectively used for adjusting the gains of the voice signals output to the receiver and the vibration motor. According to the system and the method provided by the invention, when the receiver sounds, the vibration motor vibrates synchronously according to the voice signals and drives the mobile phone to vibrate and sound; the voice generated by the vibration of the vibration motor and the voice generated by the receiver are combined; the better voice quality is obtained; and the better low frequency, the better high frequency or the higher loudness is obtained.

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 piezoelectric microelectromechanical systems diaphragm microphone can be mounted on a printed circuit board. The microphone can include a substrate with an opening between a bottom end of the substrate and a top end of the substrate. The microphone can have two or more piezoelectric film layers disposed over the top end of the substrate and defining a diaphragm structure. Each of the two or more piezoelectric film layers can have a predefined residual stress that substantially cancel each other out so that the diaphragm structure is substantially flat with substantially zero residual stress. The microphone can include one or more electrodes disposed over the diaphragm structure. The diaphragm structure is configured to deflect when the diaphragm is subjected to sound pressure via the opening in the substrate.

The invention relates to terminal equipment and a signal processing method. The terminal device includes: a screen; a sound cavity; the sound absorbing medium is positioned in the sound cavity; the vibrating diaphragm is attached to the screen, and the vibrating diaphragm and the sound absorbing medium are located on the two opposite sides in the sound cavity respectively; wherein the vibrating diaphragm is used for generating a vibration signal, and the vibration signal is used for triggering the screen to vibrate to generate a sound signal. According to the embodiment of the invention, the performance of each frequency band in the sound signal can be improved through the sound cavity and the sound absorption medium in the terminal equipment while the sound production of the screen is realized, so that the frequency response curve corresponding to the sound signal is flatter, and the sound production effect of the screen is improved.

The invention discloses a loudspeaker module, and belongs to the technical field of audio-video equipment. The module comprises: a first cavity; a second cavity which is arranged adjacent to the firstcavity; and a vibration module which is arranged in the first cavity, wherein the vibration module comprises a first vibrating diaphragm and a second vibrating diaphragm which are horizontally arranged at intervals. The first cavity comprises a first sub-cavity and a second sub-cavity which are located on the two sides of the vibration module respectively, and the second sub-cavity is communicated with the second cavity. According to the loudspeaker module provided by the invention, the condition that sharp peaks and valleys exist in a medium-high frequency curve can be improved, and a good hearing feeling is achieved; the arrangement of a powder net structure can increase the ventilation capacity between the second sub-cavity and the second cavity and prevent foreign matters in the product from contacting the second vibrating diaphragm to influence the tone quality, and a rear cavity is directly arranged below the second vibrating diaphragm, so that the design compactness of the product is improved, the space of the rear cavity is greatly increased, the low frequency is further improved, the product quality is improved, and the medium-high frequency adjusting function of the second vibrating diaphragm is not influenced.

The invention relates to the related field of PFC systems, in particular to a bidirectional PFC system adopting digital control. The bidirectional PFC system comprises a PFC main circuit, a voltage outer loop control module, a current inner loop control module and a main control chip. Through the discretization of a PIR algorithm, a totem pole PFC forward and reverse double closed-loop control algorithm is carried out, and after the algorithm is improved, the PIR algorithm is better in low-frequency and high-frequency control, the system tracking is better, a steady-state error is smaller, and the overall performance is comprehensively improved, so that the performance of an OBC is integrally improved.