30 results about "Diffuse field" patented technology

The invention is a loudspeaker for use in home theater or multi-channel sound systems that includes an enclosure, a wideband transducer, a sound absorbing pad and an aiming knob. The wideband transducer is rotatably mounted in the enclosure so that the wideband transducer can be rotated around its vertical axis and an aiming knob mechanically coupled to the wideband transducer. The wideband transducer has a front side and a rear side open so that said wideband transducer operates as a dipole transducer. The aiming knob controls the rotation angle of the dipole transducer. The loudspeaker uses the dipole transducer to create either a diffuse field or direct radiating surround sound.

In a lateral double-diffused field effect transistor of the present invention, a gate insulating film includes a first gate insulating film covering a source diffusion layer up to a region beyond the pattern of a body diffusion layer and a second gate insulating film having a film thickness larger than that of the first gate insulating film and covering a region closer to a drain diffusion layer than the region covered by the first gate insulating film. A boundary between the first gate insulating film and the second gate insulating film is composed of a straight portion parallel to a side of the pattern of the body diffusion layer and a corner portion surrounding an vertex of the pattern of the body diffusion layer from a distance. A distance between the vertex of the pattern of the body diffusion layer and the corner portion of the boundary is equal to or smaller than a distance between the side of the pattern of the body diffusion layer and the straight portion of the boundary.

A highly convenient design support method and design support system for a heat convection field or a mass diffusion field which significantly reduce the number of times of numerical simulation required to examine the designing parameters for achieving the design purpose. The design support method includes a forward analysis step of analyzing the heat convection field or the mass diffusion field by solving an equation of the heat convection field or the mass diffusion field based on an initially set value of a designing parameter, an inverse analysis step of analyzing a sensitivity defined by a change ratio of the design purpose to a designing parameter change by solving an adjoint equation corresponding to the design purpose based on the set design purpose, and a sensitivity display step of displaying information on the sensitivity analyzed by inverse analysis step as a graphic image on the display device.

The invention relates to a loudspeaker mounting and adjustment system and method for installing and operating a professional audio system used in a stadium, concert hall or the like. The system comprises a vertical array of loudspeaker cabinets that can be suspended from a ceiling and that enables the horizontal and vertical angle of the sound dispersion field to be adjusted remotely and / or automatically while the system is suspended. Each loudspeaker cabinet is connected to a vertically adjacent loudspeaker cabinet via a pair of levers located on either side of the cabinet that control the angle between adjacent loudspeaker cabinets. A linear actuator is connected to each lever for controlling the lever position. Each loudspeaker cabinet also comprises a waveguide with at least one actuator for modifying the waveguide angle and thus the horizontal angle of the sound dispersion field.

The invention provides a vertical double-diffused field-effect tube and a manufacturing process thereof. In the technical process, after a dopant region is formed, polycrystalline silicon is accumulated to form a grid; and the photoetching frequency is improved, but a photoetching plate is shared for two-time photoetching to reduce production cost. In the manufacturing process for a depletion type vertical double-diffused field-effect tube, the channel injection for the depletion tube is non self-aligned injection, so the breakdown voltage of the vertical double-diffused field-effect tube cannot be reduced, and an electric leakage problem is solved.

A plurality of acoustic sensors in a non-anechoic environment are calibrated with the aim of removing manufacturing tolerances and degradation over time but preserving position-dependent differences between the sensors, The sensors are excited by an acoustic stimulus which has either time-dependent characteristics or finite duration. The calibration is to be based on diffuse-field excitation only, in which indirect propagation (including single or multiple reflections) dominate over any direct-path excitation. For this purpose, the calibration process considers only a non-initial portion of sensor outputs and / or of an impulse response derived there-from. Based on these data, a frequency-dependent magnitude response function is estimated and compared with a target response function, from which a calibration function is derived.

The invention discloses a high-robustness P type symmetric laterally double-diffused field effect transistor, which comprises a P type substrate, wherein an N type epitaxial layer is arranged on the P type substrate; two P type drift traps, two P type buffer traps and two N type body contact regions are arranged in the N type epitaxial layer; a P type drain region and a P type source region are arranged in the P type buffer trap respectively; the surface of the N type epitaxial layer is provided with a gate oxide layer and a field oxide layer; the surface of the gate oxide layer is provided with a polycrystalline silicon gate; the surfaces of the field oxide layer, the N type body contact regions, the P type source region, the polycrystalline silicon gate and the P type drain region are provided with passivation layers; the high-robustness P type symmetric laterally double-diffused field effect transistor is characterized in that the surfaces of the two P type drift traps are also provided with a photo-etching plate shared with the low-voltage P type trap; first and second shallow P type traps formed by low-energy ion implantation are adopted; and the surface electric field distribution is effectively optimized at the region, the highest lattice temperature is reduced, the secondary breakdown current is improved and the robustness of the device in an ESD (Electronic Static Discharge) process is enhanced.

The invention discloses a three-dimensional simulation method and an emergency evacuation method for gas leakage and diffusion. The three-dimensional simulation method includes acquiring location information of a leakage source; according to the location of the leakage source, acquiring meteorological real-time data and leakage source strong data measured form the periphery; comparing and querying the meteorological real-time data with wind-field query data in a wind field database; acquiring wind field data of the leakage source from the wind field database; and introducing the wind field data and the leakage source strong data into a gas diffusion formula to calculate wind file data of the periphery of the leakage source. According to the three-dimensional simulation method, by the wind field database, the wind field data of the periphery of the leakage source is rapidly and efficiently queried and acquired, and the conventional step of wind field calculation is omitted, thus three-dimensional simulation field data are acquired within the shortest time, and requirements of chemical industrial parks and industrial enterprises for emergency systems are met in the new situation.

The invention discloses a high-sided transverse double diffused field effect transistor. The high-sided transverse double diffused field effect transistor comprises a P type substrate, an N- epitaxial layer, a P+ buried layer, a P+ P-N junction isolation, field oxygen, a P- top layer, P- body areas, a P- body area contact P+, an N+ source electrode, a gate oxygen layer, a polycrystalline silicon gate electrode and an N+ drain electrode, wherein the N- epitaxial layer is arranged above the P type substrate; the P+ buried layer and the P+ P-N junction isolation are arranged at one side of the N- epitaxial layer and are used to isolate different types of devices; furthermore, another P- body area is arranged between the P- body area and the P+ P-N junction isolation; the body area contact P+ is arranged in the P- body area; the P- top layer is arranged between the P- body area and the another P- body area. According to the high-sided transverse double diffused field effect transistor disclosed by the invention, an avalanche breakdown voltage between the source electrode and the substrate is greatly increased, that is, an isolation performance is greatly improved, so that application in the field which requires relatively high working voltage is satisfied.

The invention relates to audio transducer technology, including audio tuning systems to be utilised in personal audio devices, such as headphone, earphones, mobile phones and the like. The audio tuning system optimises the frequency response of the personal audio device by using Diffuse Field curve characteristics. The audio transducers of the personal audio device incorporate low resonance designs, including low resonance transducer and diaphragm suspensions to further optimise the sound quality of the device. The invention also relates to an audio transducer diaphragm construction that includes a three-dimensional lattice which may be utilised in any audio transducer application.

An LDFET may be formed on the basis of manufacturing platforms designed for forming sophisticated small signal transistor elements. To this end, sidewall areas of trench isolation regions laterally positioned within the drift region may be used as current paths, thereby achieving increased design flexibility, since efficient current paths may still be established, even if the trench isolation regions have to extend into the substrate material due to design criteria determined by the sophisticated small signal transistor elements. In some illustrative embodiments, isolation of P-LDFETs with respect to the P-substrate may be accomplished without requiring a deep well implantation.

A vertical double-diffused field effect transistor includes an N-type substrate, an N-type epitaxial layer formed on the N-type substrate, first and second P-type implanted regions formed on the surface of the N-type epitaxial layer, a P-type epitaxial layer formed on the N-type epitaxial layer and the first and second P-type implanted regions, first and second N-type implanted regions formed on the surface of the P-type epitaxial layer and corresponding to the first and second P-type implanted regions respectively, a silicon oxide layer formed in the P-type epitaxial layer and the first and second N-type implanted regions, first and second trenches passing through the silicon oxide layer and the first N-type implanted region and extending into the first and second P-type implanted regionsrespectively; silicon oxide formed in the inner walls of the first and the second trenches and connected with the silicon oxide layer, openings passing through the silicon oxide layer between the first and the second trenches and corresponding to the P-type epitaxial layer and the first and second N-type implanted regions, and polycrystalline silicon formed on the surface of the silicon oxide layer in the first and second trenches.

The invention provides a transverse power device high-voltage interconnection structure. An insulator area having a high dielectric constant is introduced into a drift region of a power device; and surface electrical field distribution caused by high-voltage interconnection is modulated by utilizing the area, thereby greatly enhancing voltage endurance capability of the device during high-voltageinterconnection and improving performance of the deice. The transverse power device high-voltage interconnection structure can be applied to a laterally-diffused field effect transistor LDMOS, a lateral PN diode or a lateral insulated gate bipolar transistor LIGBT, and is simple in process and low in cost.

A method of detecting the change in the structure of a turbine rotor uses the steps of injecting an ultrasonic signal into the turbine rotor at a first position using a first ultrasonic transducer to produce a diffuse field ultrasonic signal in the rotor; detecting the signal in the rotor at a second position using a second ultrasonic transducer measuring the time for the signal to travel from the first ultrasonic transducer to the second ultrasonic transducer and comparing the measured time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer with a stored time for the diffuse field ultrasonic signal to travel from the first ultrasonic transducer to the second ultrasonic transducer to determine if there is a change in the structure of the turbine rotor.

A vertical double-diffused field-effect transistor comprises an N-type substrate, an N-type epitaxial region, a first P-type body region, a second P-type body region, two first N-type injection regions, two second N-type injection regions, a third N-type injection region, a first P-type injection region, a second P-type injection region, a grid oxide layer, a poly-silicon layer, a dielectric layer, a first through hole and a second through hole, wherein the first P-type body region and the second P-type body region are formed on a surface of the N-type epitaxial region, the two first N-type injection regions are arranged on a surface of the first P-type body region, the two second N-type injection regions are arranged on a surface of the second P-type body region, the third N-type injection region is arranged on a surface of the N-type epitaxial region, the first P-type injection region is arranged between the two first N-type injection regions, the second P-type injection region is arranged between the two second N-type injection regions, the grid oxide layer and the poly-silicon layer are sequentially formed on the N-type epitaxial region, the first P-type body region, the secondP-type body region, the first N-type injection region and the second N-type injection region, the dielectric layer is formed on the poly-silicon layer and on the first N-type injection region, the second N-type injection region and the third N-type injection region, the first through hole penetrates through the dielectric layer and is corresponding to the first N-type injection region and the first P-type injection region, and the second through hole penetrates through the dielectric layer and is corresponding to the second N-type injection region and the second P-type injection region.

The invention discloses a high-sided transverse double diffused field effect transistor. The high-sided transverse double diffused field effect transistor comprises a P type substrate, an N- epitaxial layer, a P+ buried layer, a P+ P-N junction isolation, field oxygen, a P- top layer, P- body areas, a P- body area contact P+, an N+ source electrode, a gate oxygen layer, a polycrystalline silicon gate electrode and an N+ drain electrode, wherein the N- epitaxial layer is arranged above the P type substrate; the P+ buried layer and the P+ P-N junction isolation are arranged at one side of the N- epitaxial layer and are used to isolate different types of devices; furthermore, another P- body area is arranged between the P- body area and the P+ P-N junction isolation; the body area contact P+ is arranged in the P- body area; the P- top layer is arranged between the P- body area and the another P- body area. According to the high-sided transverse double diffused field effect transistor disclosed by the invention, an avalanche breakdown voltage between the source electrode and the substrate is greatly increased, that is, an isolation performance is greatly improved, so that application in the field which requires relatively high working voltage is satisfied.

The invention discloses a high-robustness P type symmetric laterally double-diffused field effect transistor, which comprises a P type substrate, wherein an N type epitaxial layer is arranged on the P type substrate; two P type drift traps, two P type buffer traps and two N type body contact regions are arranged in the N type epitaxial layer; a P type drain region and a P type source region are arranged in the P type buffer trap respectively; the surface of the N type epitaxial layer is provided with a gate oxide layer and a field oxide layer; the surface of the gate oxide layer is provided with a polycrystalline silicon gate; the surfaces of the field oxide layer, the N type body contact regions, the P type source region, the polycrystalline silicon gate and the P type drain region are provided with passivation layers; the high-robustness P type symmetric laterally double-diffused field effect transistor is characterized in that the surfaces of the two P type drift traps are also provided with a photo-etching plate shared with the low-voltage P type trap; first and second shallow P type traps formed by low-energy ion implantation are adopted; and the surface electric field distribution is effectively optimized at the region, the highest lattice temperature is reduced, the secondary breakdown current is improved and the robustness of the device in an ESD (Electronic Static Discharge) process is enhanced.

The invention discloses a wide-bandgap semiconductor lateral double-diffused field effect transistor with a transverse and longitudinal electric field simultaneous optimization function. An assisted depletion substrate buried layer is arranged below a drift region at the drain end, and a substrate buried layer with partial charge compensation is arranged in a substrate area below the drift regionof LDMOS and near the assisted depletion substrate buried layer. A new electric field peak is introduced to the surface transverse electric field of the device, so that the surface transverse electricfield of the device is distributed more uniformly, and the surface transverse electric field of the device is well optimized. A new electric field peak is also introduced to the inside longitudinal electric field distribution of the device, which further optimizes the inside longitudinal electric field. The structure breaks through the voltage saturation phenomenon caused by the limited longitudinal withstand voltage. Most importantly, the surface transverse electric field and the inside longitudinal electric field can be optimized simultaneously, and the breakdown voltage of the device is greatly improved.

A double diffused field effect transistor and a method of forming the same is provided. The method begins by providing a substrate of a first conductivity type. Next, at least one dopant species, also of the first conductivity type, is introduced into a surface of the substrate so that the substrate has a nonuniform doping profile. An epitaxial layer of the first conductivity type is formed over the substrate and one or more body regions of a second conductivity type are formed within the epitaxial layer. A plurality of source regions of the first conductivity type are then formed within the body regions. Finally, a gate region is formed, which is adjacent to the body regions.