79results about How to "Low noise performance" patented technology

The invention provides a monolithic integrated three-axis accelerometer and a manufacturing method thereof so as to solve the defects in structure and manufacturing technology of the existing structural capacitive accelerometer. Three layers of metal Al thin films are deposited in the direction of an axis Z so as to form a comb pair sensitive electrode; four layers of metal Al/SiO2 thin films are deposited in the directions of an axis X and an axis Y so as to form comb pair sensitive electrodes, and the accelerations of the three axis directions are detected simultaneously by a single integrated structure. The accelerometer and the manufacturing method thereof have the following positive technical effects: the interconnection stray capacitance among accelerator devices in three axis directions is lowered remarkably, and high detection accuracy and lower noise performance are realized; since the accelerometer is provided with the multiple metal layers, compared with a microaccelerometer manufactured from the same material, namely polycrystalline silicon, the accelerometer is more flexible in wiring; a foldable beam is used in the structure of the accelerometer, so that the own stress of the accelerometer is released better, and therefore the influence of the stress on the system can be reduced effectively.

A switchable gain amplifier for use in mobile communications devices is provided, having a first amplifier stage having a first gain, a second amplifier stage connected in parallel with the first amplifier stage. The first and second amplifier stage have different gains and a gain controller, connected to the first amplifier stage and to the second amplifier stage, enables only one of the amplifier stages at a time.

A flux locked loop for providing an electrical feedback signal, the flux locked loop employing radio-frequency components and technology to extend the flux modulation frequency and tracking loop bandwidth. The flux locked loop of the present invention has particularly useful application in read-out electronics for DC SQUID magnetic measurement systems, in which case the electrical signal output by the flux locked loop represents an unknown magnetic flux applied to the DC SQUID.

A CMOS differential power amplifier having broadband input matching with Noise and Non-linearity Cancellation. The broadband input match is realized by using two “Diode-Connected” NFETs (i.e., N-type Field Effect Transistors). Resulting noise degradation is reduced by using a noise cancellation structure. By using the same structure the disclosed method and apparatus also achieves non-linearity cancellation.

The invention discloses a bionic microporous noise-reducing structure which is used for an oil fume extraction system. The structure comprises a shell body; oil fume passes by the inner cavity of the shell body and contacts with the inner wall of the shell body; the invention is characterized in that the outer side of the shell body is fixedly provided with a noise-reducing box which is enclosed at the periphery; the noise-reducing box is internally provided with at least one layer of porous plate which is distributed with tight millipores, so the noise-reducing box is divided into at least an inner cavity and an outer cavity; the shell body which is opposite to the porous plate and enclosed in the noise-reducing box is coated and distributed with an oil-preventing coat, moreover, bar-shaped pores are tightly distributed on the shell body; the inner cavity of the shell body is communicated with the inner cavity of the noise-reducing box by the bar-shaped pores, moreover, the bar-shaped pores are slits of louver window type and the vanes of the slits are self-locked. The invention uses a principle of fluid mechanics for effectively preventing the oil fume from blocking the millipores at places such as cochlear duct, air exhaust pipe and the like, finally ensures that the noise-reducing box can effectively achieves the aims of long-term sound absorption and noise reduction, and is especially suitable for household oil fume extraction machine.

The invention discloses a hydraulic-motor piston pump with the purpose that electric energy is transmitted to hydraulic energy directly by machine winding directly driving cylinder body connected integrally with motor rotor. Motor stator 8, in which machine winding 7 and motor rotor 20 are set, is set in pump shell 5, rotor bar 10 is uniformly set in motor 20, on the two sides of motor rotor end face there are two end ring 9, the cylinder body 12 is set in the inner hole of motor rotor 20, inlet 18a is opened on right pump cap 18, outlet 1a is opened on left pump cap 1, multiple pistons 13 is uniformly set in pump shell 5, the piston 13 is tightly contacted with the bevel 18b of right pump shell 18 by slipper 15, return disc 14, ball hinge 16 and retracting spring 19.

The invention particularly relates to an oil-free vortex air compressor which comprises a rack, a static disc, a movable disc, a shaft sleeve, a crankshaft and pin cranks. The static disc is installed in the mode of being matched with the end face of the rack. The movable disc is installed in the mode of being matched with the end face of the shaft sleeve and located in the rack. A pin crank bearing at one end of each pin crank is installed on the rack, and a pin crank bearing at the other end of each pin crank is installed on the shaft sleeve. The shaft sleeve and the at least three pin cranks are restrained. The static disc and the movable disc driven by the crankshaft form a sealing cavity in continuous suction, compression and exhaust working states. Movable disc fins of a step type are arranged on the back of the movable disc. The shaft sleeve of a step type is installed on the movable disc fins. Clearance is reserved between all the bearing pedestal positions on the shaft sleeve and the movable disc fins. The air compressor has the advantages that the movable disc fins are utilized for being distributed on the back of the movable disc in a ladder shape, on the condition that the total length of the movable disc and the total length of the shaft sleeve is not changed, the heat dissipating area of the back of the movable disc is effectively increased, and the cooling effect is further achieved.

The invention discloses an ice condensation resistant ultra-thin wearing course pavement and a preparation method thereof. The ice condensation resistant ultra-thin wearing course pavement is prepared from the following raw materials in parts by weight: 15-17 parts of 10-15 mm gravels, 14-16 parts of 5-10 mm gravels, 11-13 parts of stone chips of which the particle size is smaller than 3 mm, 3-5 parts of ice condensation resistant agents, 2.2-2.6 parts of modified asphalt, and 1.1-1.4 parts of polymer modified emulsified asphalt, wherein the content of sodium chloride in the ice condensation resistant agents is 50-60%, and the solid content of the polymer modified emulsified asphalt is greater than or equal to 65%. According to the invention, ice condensation resistant ultra-thin wearing courses are paved on the pavement, so that the ice point of water in the surface of the pavement is reduced, snow accumulation and icing on the pavement are delayed, a new solution is put forward for solving the problem of the congelation of the pavement in winter is restrained, and safe running on the pavement is ensured.

The invention discloses a distortion and noise cancellation based high-linearity CMOS broadband low noise amplifier. The distortion and noise cancellation based high-linearity CMOS broadband low noise amplifier structurally comprises a distortion cancellation input stage and a noise cancellation output stage. The distortion cancellation input stage serves as a first stage of the low noise amplifier, input impedance matching and second-order cross modulation IMD2 cancellation are achieved by adopting CMOS complementary common-gate combination, meanwhile a complementary structure has the characteristic of current reuse, and accordingly power consumption is reduced. The noise cancellation output stage serves as a second stage and is mainly used for cancelling channel thermal noise current of two common-gate devices at the first stage and accordingly reducing the noise coefficient of a whole circuit. The distortion and noise cancellation based high-linearity CMOS broadband low noise amplifier can simultaneously achieve high linearity and low noise coefficient within a broadband range, and meanwhile gives consideration to other design parameters, such as input impedance matching, power gain and power consumption.

The present invention relates to a fan shroud assembly and, more specifically, to a fan shroud assembly comprising: vortex-preventing saw-teeth which are arranged along a predetermined inner circumferential surface of a ventilating unit so as to maintain a predetermined gap with a blade end part or a band end part of a fan, and which are formed in a saw-toothed shape, wherein both a first area in which the vortex-preventing saw-teeth are formed and a second area from which the vortex-preventing saw-teeth are removed are formed, thereby generating vortexes of ventilated air due to a reduction in pressure fluctuation and thus effectively reducing noise.

The invention relates to a scroll compressor with an injection channel, in particular to an injection channel and noise reduction structure of the scroll compressor, which belongs to the technical field of scroll compressors. A motor stator is fixedly installed at the lower part in a housing, a motor rotor is installed in the motor stator, and the motor rotor is installed at the bottom of a crank shaft; an upper support and a movable scroll are installed on the crank shaft, a cross ring is installed between the movable scroll and the upper support, and a stationary scroll is fixed on the upper support; the stationary scroll is fitted with the movable scroll to form a plurality of compressed cavities, and an upper cover covers on the housing. The scroll compressor with the injection channel has the characteristicsis characterized in that a valve plate is installed on the stationary scroll through a bolt hole on the valve plate and a screw, the valve plate is provided with a main ejection channel and an ejection channel communicated with the main ejection channel, a through channel which is communicated with an ejection port on the stationary scroll is arranged at the lower part of the ejection channel, a groove is arranged at the lower part of the valve plate and encloses the stationary scroll to form a space, and an ejection pipe is installed on the main ejection channel.

Receivers for diversity reception of data transmitted by concatenated convolutional code (CCC) from at least one 8-VSB transmitter are described. Each receiver includes a first turbo decoder for the CCC as finally transmitted, a second turbo decoder for the CCC as initially transmitted, and an information-exchange unit connected for exchanging decoding information between the turbo decoders, which perform decoding concurrently. The turbo decoders are designed for decoding CCC formed from an outer convolutional code encoding de-interleaved Gray-coded data and a subsequent binary-coded inner convolutional code forming a 12-phase trellis code in accordance with a Gray-labeling procedure, the outer convolutional code encoding being symbol-interleaved before encoding within said inner convolutional code so said inner convolutional code has implied symbol interleaving in which the original order of data bits is preserved.

A communications cabling front-end architecture that achieves solid echo cancellation and lower noise performance by combining an echo-cancellation circuit and an equalizer function at the same point, at the most front-end of the system.

The invention provides a pneunatic tyre which prevents water discharging performance and improves uneven wear resistance and noise performance. The tire tread is provided with a central main groove in an equatorial plane of the tire, a pair of central auxiliary grooves at two sides of the central main groove, and a pair of tire shoulder main grooves at two sides, thereby forming central landing parts, middle landing parts and tire shoulder landing parts. Each middle landing part is provided with middle transverse grooves which are separately arranged in a circumferential direction and respectively extend from the central auxiliary groove to the tire shoulder main groove in an angle beta in 10-20 DEG. Each middle transverse groove is composed of a large-width part which is connected with the central auxiliary groove, a small-width part which is connected with the tire shoulder main groove, and a transition part which connects the large-width part with the small-width part. The angle beta of the middle transverse groove is larger than the angle alpha of the grounding front edge part of the middle landing part in the shape of a grounding surface.

The invention discloses a high-toughness, durable and antiskid steel bridge deck pavement structure and a construction method thereof. The steel bridge deck pavement structure comprises a steel bridgedeck steel plate; a bonding bottom layer, a buffer layer, an adhesion layer and a wearing layer are sequentially laid on the surface of the steel bridge deck steel plate from bottom to top; the buffer layer and the wearing layer are both made of high-toughness modified asphalt concrete composed of aggregate, filler and asphalt cement, the thickness of the buffer layer is 1-3 cm, and the thicknessof the wearing layer is 2-3 cm. The bridge deck pavement structure has good high-temperature rut resistance, fatigue durability, skid resistance, bonding strength and deformation compliance, comparedwith epoxy asphalt concrete, the engineering cost is greatly reduced, the construction process is simple, and later maintenance is convenient.

The invention relates to a PET image reconstruction method and system. The method comprises the steps that 101, PET computing equipment acquires detection data in detection equipment; 102, the PET computing equipment acquires a regularization target function phi(x, y) = L(x, y)-beta * R(x) for reconstructing an image according to the detection data, wherein L(x, y) is a likelihood function item corresponding to the detection data, R(x) is a priori knowledge item, and beta is a regularization parameter and is used for adjusting the weights of L(x, y) and R(x); 103, the PET computing equipment determines a parameter beta in a regularization target function according to the signal-to-noise ratio information and the input parameter of the detection data; 104, the PET computing equipment reconstructs a PET image according to the determined parameter beta and the regularization target function, and finally the purpose of improving the quality of the reconstructed PET image is achieved.