268 results about "Zero bias" patented technology

An optical communications transceiver includes an LED coupled in series with a resistor. A microprocessor has one I/O pin connected to the LED. In a first mode or transmit mode, the LED is periodically driving in forward bias to emit light to transmit data. In a second or receive mode, the LED is periodically not driven in reverse bias, e.g., reverse bias or zero bias. Then, the LED is allowed to change charge of the capacitance of the LED's junction using a photo-current. The change in charge is measured using a timer. When the change in charge exceeds a predetermined threshold, input light is sensed. Thus, the LED can be used to receive data in the second mode.

The invention discloses a method for determining the driving state of a vehicle based on an acceleration sensor. The method comprises the following steps of: A, acquiring the longitudinal acceleration, the transverse acceleration and the vertical acceleration of an automobile by using a three-axial acceleration sensor; B, calculating a conversion matrix of an automobile coordinate system and an acceleration sensor coordinate system, acquiring the initial attitude of the acceleration sensor, namely the initial angle between the acceleration sensor and the automobile, and performing zero bias filtering processing on the acquired accelerations so as to acquire the acceleration value of the automobile coordinate system; and C, determining the driving state of the vehicle according to the acceleration values of a plurality of continuous automobile coordinate systems. In the method for determining the driving state of the vehicle based on the acceleration sensor, the original data is acquired by the acceleration sensor, and the driving state of the vehicle is determined by analyzing and processing three axial accelerations, so that the driving behaviors and the driving state of a driver are known, vehicle managers are assisted in normalizing the driving behaviors, dangerous driving behaviors are prevented, and driving safety is ensured.

The invention discloses a double-closed-loop control circuit of a micromechanical gyroscope and belongs to the field of guide or control devices based on a Coriolis effect. The circuit is used for closed-loop control of driving and detection modes of the micromechanical gyroscope. A simplified self-oscillation closed-loop control circuit based on automatic gain control (AGC) is employed for the driving mode of the circuit, and the frequency stability and amplitude stability of the micromechanical gyroscope in the driving mode can be effectively improved; and a six-order continuous band-pass Sigma Delta M closed-loop control circuit for the detection mode has six-order noise reshaping capacity, and the signal to noise ratio (SNR), linearity and zero-bias stability of a system detection signal can be improved. The double-closed-loop control circuit of the micromechanical gyroscope is easy to control and simple, the accuracy of a system is improved, the SNR of the system is high, and the system is self-adaptively adjusted and high in stability.

The invention discloses a capacitance testing circuit and capacitance-type sensor interface circuit chip thereof, which relates to the sensor device field and resolves problems that the capacitance testing circuit has complicated structure and the capacitance-type sensor interface circuit chip has large volume and is inefficient. The capacitance testing circuit includes a capacitance readout front end circuit, a demodulation amplifying circuit whose input end is connected to the capacitance readout front end circuit, and a buffering amplifying circuit whose input end is connected to the demodulation amplifying circuit. The capacitance-type sensor interface circuit chip includes a self measuring circuit, a bias current producing circuit, a sensor zero bias compensating circuit, a reference voltage generation circuit, a clock generation circuit, and a capacitance testing circuit respectively connected to the circuits; the self measuring circuit and the sensor zero bias compensating circuit are respectively connected to a outer capacity sensor; the capacitance-type sensor interface circuit chip is prepared by using an integrate circuit technique. The invention is suitable for open-loop or equilibrium closed-loop accelerameter and vibratory rate gyroscope.

The invention discloses a main pin zero bias wire-controlled independent driven and steering automobile running mechanism and an electric vehicle for solving the problems of complex mechanism and low vehicle stability. The mechanism consists of a steering component, a suspension component and a wheel component. The steering component consists of a main pin assembly and a steering vertical shaft assembly. The main pin assembly comprises a steering motor (1), a speed reducer (2), a speed reducer output flange (3), a main pin sleeve (5), a main pin (6) and a coding disc (7); and the steering vertical shaft assembly comprises a main steering arm (8), a steering vertical shaft (12), an upper distance plate (19) and a lower distance plate (24). The suspension component comprises an upper springseat (10), a shock absorber (11), a spring (13) and a lower spring seat (14). The wheel component comprises a hub motor (16), a wheel (18) and a wheel bracket (22). The electric vehicle consists of aframe (28), the main pin zero bias wire-controlled independent driven and steering automobile running mechanism (27) and an electric control system.

An ultrasound transducer is constructed to be under damped at higher overtone frequencies by reducing losses through one or more of the following: even pressure shaped surfaces on masses, reversed drive to at least one piezoelectric ceramic, an ultrasonically formed metallic bond between the transducer's front mass and the radiating surface, high current carrying strain relieved electrodes, fine grain structure masses, low internal friction masses and radiating materials, and zero bias stress change due to temperature variations. Improved methods and construction details for bonding the higher overtone frequency transducer to quartz are disclosed and include: front masses with cross-hatched or concentric circle patterns and invar front masses or an invar transition mass that is bonded to the quartz.

The invention is the project realizing method of fiber top inertia measuring device fast starting and precision guarantee, which adopts the temperature demarcating system to detect the temperature mode; found the module of the affirming parts of the fiber top and the quartz accelerator and effectively reduce the zero-bias brought by the temperature; implement small-wave transforming procession to the fiber top noises and make the stability of the zero-bias be better than 0.5 Deg./h and the zero-bias error be smaller than 10 to power 4 g. The invention effectively reduces the zero temperature floating and noises and improves the performance of the system.

A substrate has three or more overlay gratings formed thereon by a lithographic process. Each overlay grating has a known overlay bias. The values of overlay bias include for example two values in a region centered on zero and two values in a region centered on P/2, where P is the pitch of the gratings. Overlay is calculated from asymmetry measurements for the gratings using knowledge of the different overlay bias values and an assumed non-linear relationship between overlay and target asymmetry, thereby to correct for feature asymmetry. The periodic relationship in the region of zero bias and P/2 has gradients of opposite sign. The calculation allows said gradients to have different magnitudes as well as opposite sign. The calculation also provides information on feature asymmetry and other processing effects. This information is used to improve subsequent performance of the measurement process, and/or the lithographic process.

The invention relates to an MEMS accelerometer with the temperature compensation function. The MEMS accelerometer with the temperature compensation function comprises an acceleration sensor, a temperature sensor and a temperature compensation chip, wherein the acceleration sensor and the temperature sensor are connected with the temperature compensation chip. A temperature compensation method adopted by the temperature compensation chip comprises the steps that (1), zero biases and a set of output values of a scale factor are measured under a plurality of temperature points, the zero biases and the output values are fitted to be a fitting surface, and a series of fitting coefficients are obtained and arranged to be a coefficient matrix; (2), modeling is carried out on output signals of the acceleration sensor and the output signals of the temperature sensor so as to be expressed as a model matrix; (3), dot product is carried out on the coefficient matrix and the model matrix so as to obtain an output formula after the acceleration sensor obtains the temperature compensation; (4), the fitting coefficients and the output formula are written into the temperature compensation chip to be calculated. Through three-dimensional fitting of the surface and compensation after calculation, influence on a system from errors generated when the accelerometer is assembled and installed is reduced effectively.

A cobalt iron hafnium oxide (CoFeHfO) layer is employed in a pinned layer structure of a top or bottom simple pinned or antiparallel (AP) pinned spin valve sensor for increasing a demagnetization field from the pinned layer structure which will improve biasing of a free layer structure in the spin valve sensor with minimal shunting of the sense current IS through the spin valve sensor because of its high resistance. The demagnetization field from the pinned layer structure opposes a typically high sense current field due to the sense current so as to zero bias the spin valve sensor with a magnetic moment of the free layer structure oriented parallel to an air bearing surface of the sensor. The cobalt iron (CoFe) content in the cobalt iron hafnium oxide (CoFeHfO) layer increases the magnetoresistance of the sense current due to its proximity to the spacer layer and the oxygen content in the layer causes specular reflection of conduction electrons through the sensor for still further increasing the magnetoresistance.

The invention discloses a MEMS (micro-electro-mechanical system) fully decoupled closed-loop gyroscope. The gyroscope comprises a substrate and a sensitive device layer, wherein an insulating layer isarranged between the substrate and the sensitive device layer; the sensitive device layer comprises a first substructure, a second substructure and a coupling connection beam; each of the first substructure and the second substructure comprises a driving frame, driving folding beams, driving decoupling beams, a Coriolis mass block, a detection frame, detection beams, detection decoupling beams, driving fixed comb teeth, driving movable comb teeth, driving detection fixed comb teeth, driving detection movable comb teeth, detection fixed comb teeth, detection movable comb teeth, force feedbackfixed comb teeth, force feedback movable comb teeth and anchor points. Generation of quadrature error signals is suppressed, and the zero bias stability index of the MEMS gyroscope is improved; the gyroscope has compact structure and small chip area, and can prevent a detection-mode sensitive mass from twisting due to larger displacement, thereby having good overall linearity and high measurementaccuracy.

The invention relates to a method of applying a coating by physical vapour deposition onto an article of organic material, in particular of non- conductive organic material such as plastic and/or epoxy material, especially ABS (Acrylonitrile-Butadiene-Styrene Copolymers) and polymers with high temperature resistance, or onto an article of another composition coated with such organic material, wherein a Cr layer is deposited on the article prior to deposition of said coating to form a diffusion barrier for water coming from said article, said Cr layer itself being deposited by a physical vapour deposition process comprising at least the following steps:a) depositing a first layer of Cr on said article in a physical vapour deposition apparatus using an arc evaporator or cathode sputtering source, or in a combined arc evaporator and cathode sputtering apparatus, using zero bias, andb) subsequently applying a negative bias voltage to said article having said first layer of Cr and depositing a further layer of Cr on said first layer using Cr ions in the same physical vapour deposition apparatus.

A pulsed plasma system with pulsed sample bias for etching semiconductor structures is described. In one embodiment, a portion of a sample is removed by applying a pulsed plasma process, wherein the pulsed plasma process comprises a plurality of duty cycles. A negative bias is applied to the sample during the ON state of each duty cycle, while a zero bias is applied to the sample during the OFF state of each duty cycle. In another embodiment, a first portion of a sample is removed by applying a continuous plasma process. The continuous plasma process is then terminated and a second portion of the sample is removed by applying a pulsed plasma process.

The invention aims at providing a single-axle table calibration method for a fiber optic gyro strapdown inertial navigation system. The fiber optic gyro strapdown inertial navigation system is placed on a single-axle table, the fiber optic gyro strapdown inertial navigation system is electrified for preheating, the angular velocity outputted by a fiber optic gyro and the specific force outputted by a quartz flexible accelerometer are collected, then the single-axle table is controlled to rotate at 90 degrees counter-clockwise around a rotating shaft three times, the angular velocity outputted by the fiber optic gyro and the specific force outputted by the quartz flexible accelerometer at each time are respectively collected, and the drift of the fiber optic gyro in an x, y and z-axis coordinate system of an inertia device and the zero bias value of the quartz flexible accelerometer in the x, y and z-axis coordinate system of the inertia device are further obtained. The method can measure the drift of the fiber optic gyro and the zero bias value of the quartz flexible accelerometer by utilizing the single-axle table to rotate into different angular positions; furthermore, the calibration cost of the single-axle table is low, the steps are simple, and the single-axle table only needs to be placed on the ground during the calibration without a laboratory.

A method is provided for plasma ashing to remove photoresist remnants and etch residues that are formed during preceding plasma etching of dielectric layers. The ashing method uses a two-step plasma process involving an oxygen-containing gas, where low or zero bias is applied to the substrate in the first cleaning step to remove significant amount of photoresist remnants and etch residues from the substrate, in addition to etching and removing detrimental fluoro-carbon residues from the chamber surfaces. An increased bias is applied to the substrate in the second cleaning step to remove the remains of the photoresist and etch residues from the substrate. The two-step process reduces the memory effect commonly observed in conventional one-step ashing processes. A method of endpoint detection can be used to monitor the ashing process.

The invention provides a piezoresistive sensor circuit capable of automatically correcting zero-bias. The invention provides an interface circuit capable of automatically correcting the zero point bias voltage of a piezoresistive sensor so that the measuring results can be more precise. When a piezoresistive sensor system is electrified, a successive approximation principle is utilized for automatically correcting the output of the piezoresistive sensor system, the unchanged correction voltage can be maintained for a long time, and in addition, the time drift problem does not exist. The invention overcomes the defects of the existing piezoresistive sensor circuit, and has the characteristic of automatically correcting the output voltage of the sensor.

The invention relates to a fiber-optic gyroscope zero-bias stability improvement method based on a polynomial fitting technology. The method comprises the following steps: step 1, establishing a polynomial fitting compensation model; step 2, selecting polynomial fitting compensation parameters. The fiber-optic gyroscope zero-bias stability improvement method based on the polynomial fitting technology is established and based on the polynomial compensation method, compensation related parameters are quantified, the problem that fiber-optic gyroscope zero-bias is affected by temperature change easily is solved, and the effects of temperature on the accuracy of a fiber-optic gyroscope are reduced. The main content relates to establishment of the fiber-optic gyroscope zero-bias compensation polynomial fitting compensation model and selection of polynomial fitting compensation parameters.

This invention relates to a large power TDD RF-power amplifier composed of a LDMOS power amplifying circuit and a grid switch control circuit, in which, the first pin of a single-pole double-throw analog switch is connected with one end of a resistor, the other end of the resistor is linked to the earth, the second pin of the switch is connected with the 5V supply, the third and the fourth are connected to the earth directly, the fifth is parallel to one pin of a condenser, the sixth is parallel to the grid voltage, one end of a condenser and the other is connected to the earth. This invention applies the high-speed analog switch circuit to switch the grid of LDMOS to work between zero-bias and the static current bias to switch the working state of the amplifier to realize the TDD mode of the amplifier.

In one illustrative example disclosed, a magnetic storage device includes at least one magnetic disk; a magnetic head which includes first and second read sensors; a suspension which supports the magnetic head relative to the magnetic disk; and read circuitry which includes a preamplifier. The preamplifier has a first input port coupled to the first read sensor; a second input port coupled to the second read sensor; a first bias source coupled to the first input port for actively current/voltage biasing the first read sensor; a second bias source coupled to the second input port for zero biasing the second read sensor; and a subtractor having first and second inputs coupled to the first and the second input ports, respectively. The first input of the subtractor is provided with a first signal which includes a read sensor data signal and an interference signal, whereas the second input of the subtractor is provided with a second signal which includes the interference signal but not the read sensor data signal. Thus, an output of the subtractor provides a read sensor signal without the interference signal.