87 results about "Curvature compensation" patented technology

The invention discloses a segmented linear compensated CMOS band gap reference voltage source, characterized in that it comprises IPTAT current generation part, ICTAT current generation part, low temperature segment compensation current ICL generation part and high temperature segment compensation current ICH generation part. On the basis of traditional first-order curvature compensation, it divides the whole temperature range into high, medium and low temperature segments, compensates output voltage in each temperature range respectively and makes the output voltage have multiple local extremum points in the whole temperature range to achieve the segmented compensation purpose, so as to effectively improve the temperature characteristics of output voltage reference, reduce temperature coefficients and improve accuracy of output voltage. Besides, it can change amplitude of output voltage by regulating resistor ratio value, relatively flexible to use. The whole circuit has low power consumption and occupies smaller chip area.

The invention relates to a CMOS band gap reference voltage source with a curvature compensation circuit, which comprises a start circuit, a reference core circuit, a curvature compensation circuit and a reference voltage output circuit, The invention uses the PTAT current to form a PTAT voltage on a resistance to check temperature change, wherein the current of ms1 mirror image forms the voltage V(P06) on RC2, while the voltage is in direct proportion with temperature, and the invention uses the exponent relation between the voltage difference VEB of QC2 emitter and base of BJT transistor and the collector current of BJT and the similar linear relation between the collector current and base current to form the dynamic compensation on reference voltage which converts the check voltage varying linearity along with temperature into the compensation current in exponent type.

A complementary metal oxide semiconductor (CMOS) band-gap reference circuit based on negative feedback relates to an integrated circuit. The circuit is provided with a core reference voltage module with negative feedback, a power supply stabilizing module, a power supply rejection ratio (PSRR) reinforcing module, a low temperature high order curvature compensation module and a starting module. The core reference voltage module with the negative feedback generates band-gap reference voltage, and the output end of the core reference voltage module with the negative feedback is respectively connected with the input ends of the PSRR reinforcing module and the low temperature high order curvature compensation module. The power supply stabilizing module provides a stabling power supply to other modules, and the output end of the power supply stabilizing module serves as the power supply input ends of other modules. The output end of the PSRR reinforcing module is connected with the power supply input ends of the core reference voltage module with the negative feedback, the power supply stabilizing module, the low temperature high order curvature compensation module and the starting module. The output end of the low temperature high order curvature compensation module is connected with the output end of the core reference voltage module with the negative feedback and outputs final reference voltage. The output end of the starting module is respectively connected with the core reference voltage module with the negative feedback and the power supply stabilizing module.

The invention discloses a transverse lateral curve flight-path tracking method based on curvature compensation and belongs to the technical field of flight-path tracking control. The transverse lateral curve flight-path tracking method based on curvature compensation comprises the following steps of: obtaining discrete flight-route point data of a reference flight path by a flight-path planning module; carrying out piecewise interpolation fitting processing on the obtained discrete flight-path point data by a Lagrange piecewise polynomial interpolation method to obtain a curve flight path; calculating the lateral offset distance of an unmanned plane at the present moment, and calculating a curvature value of a point, closest to the plane, on the reference flight path by referencing the coordinates of the point, closest to the plane, on the reference flight path; and completing the whole curve flight-path tracking process by using the obtained lateral offset distance and the curvature value as input variables of a transverse lateral controller of the unmanned plane. According to the transverse lateral curve flight-path tracking method disclosed by the invention, the curve interpolation fitting processing is carried out on the reference flight path, so that the transitional section of the flight path points in the tracking process is smoother and the tracking errors are smaller, therefore, the flight path can be tracked better.

The invention discloses a band-gap reference voltage source with high-order curvature compensation, which comprises a starting circuit, an auxiliary reference circuit, an index curvature compensation circuit, a logarithm curvature compensation circuit and a current superposed circuit. The reference voltage source disclosed by the invention acquires the index curvature compensation in a low-temperature area by the auxiliary reference circuit and the index curvature compensation circuit, and acquires the logarithm curvature compensation in a high-temperature area by the logarithm curvature compensation circuit, so that the temperature drift is efficiently reduced in the whole temperature range. The reference voltage source has better temperature stability and PSRR (power supply rejection ratio) property and can normally work under the condition that the input voltage is reduced to 1.6V. By using the band-gap reference voltage source, low temperature drift is realized while the circuit consumption is reduced and the working voltage is lower.

A high precision, curvature compensated bandgap reference circuit with programmable gain is provided. An exemplary bangap reference circuit comprises a curvature compensation circuit configured for compensation of the temperature coefficient characteristic of the bandgap reference circuit, and a programmable gain circuit configured for adjusting the gain the output of the curvature compensation circuit to provide a high precision reference voltage. To facilitate high precision and accuracy, each of the curvature compensation circuit and the programmable gain circuit are configured for trimming during operation / after manufacture. Trimming of the temperature compensation circuit is facilitated by a first digital-to-analog (DAC) device. The programmable gain circuit comprises a gain trimming circuit comprising a second DAC. The first DAC and second DAC can be suitably controlled in various manners, including use of microcontroller circuit having flash memory configured for storing and loading trim values into the first DAC and second DAC.

The invention provides a bandgap reference circuit with a high power supply rejection ratio and high order curvature compensation. The bandgap reference circuit comprises a starting circuit, a forward-acting regulator circuit, a bandgap circuit, a low temperature area piecewise linear temperature compensation circuit, a temperature compensation circuit with a high temperature area and the absolute temperature T1.5 in direct proportion and a high temperature area piecewise linear temperature compensation circuit. A low temperature area piecewise linear temperature compensation current and a temperature compensation current with the high temperature area and the absolute temperature T1.5 in direct proportion are added in a traditional bandgap reference circuit, a high temperature area piecewise linear temperature compensation current is drawn out of the traditional bandgap reference circuit, and accordingly the reference circuit with the high order curvature compensation is obtained; a negative feedback forward-acting regulator technology is added into reference voltage with high order curvature compensation, and accordingly the bandgap reference circuit with the high power supply rejection ratio and the high order curvature compensation is obtained.

The invention discloses a voltage reference source capable of compensating in a full-temperature range, which particularly comprises a start-up circuit, a first-order temperature-compensation circuit, a proportional superposition output circuit and a current bias circuit, and is characterized by further comprising a low-temperature high-order compensation circuit, a high-temperature high-order compensation circuit and a negative feedback circuit. The voltage reference source adopts index curvature compensation at the low temperature, adopts piecewise linear curvature compensation at the high temperature, has extremely good temperature stability and extremely low temperature coefficient and can be applied to an analogue integrated circuit, a high-precision digital-to-analogue conversion circuit and a pure digital integrated circuit.

In a voltage reference circuit, a bandgap reference circuit, for generating a bandgap reference voltage and a reference current, includes an operation amplifier, and a first transistor for providing the reference current. Another transistor mirrors the reference current to provide a first current. A compensation controller converts a node voltage from the bandgap reference circuit into a second current and performs current subtraction on the first current and the second current to provide a compensation feedback current to another node of the bandgap reference circuit. So that, second order temperature compensation is performed on the bandgap reference voltage.

The invention discloses a closed-loop curvature compensation CMOS band-gap reference voltage source, belonging to the field of power and microelectronics technology. The reference voltage source includes: a CTAT current generation circuit, for generating PTAT current (I [PTAT]); a closed-loop compensation current generating circuit, for generating closed-loop compensation current (I [CL]); a voltage generating circuit in reference to the generated closed-loop compensation current (I [CL]), for generating a reference voltage source (Vref), wherein, the PTAT current generation circuit is connected to the CTAT current generating circuit, the CTAT current generation circuit is connected to the closed-loop compensation current generating circuit, the reference voltage generation circuit is connected to the CTAT current generation circuit and the closed-loop compensation current generating circuit. The closed-loop curvature compensation CMOS band-gap reference voltage source structure provided by the invention can effectively improve the accuracy of compensation current, thereby increasing the temperature stability of the output reference voltage.

The invention discloses a band-gap reference voltage source with wide input belt point curvature compensation, and the band-gap reference voltage source is mainly used for solving the problems of low source rejection ratio and low temperature stability. The band-gap reference voltage source comprises a pre-bias circuit (1), a positive and negative temperature coefficient current generation circuit (3), a voltage / current conversion circuit (4) and a reference voltage generation circuit (5). The output voltage VBIAS of the pre-bias circuit (1) is output to the positive and negative temperature coefficient current generation circuit (3), the voltage / current conversion circuit (4) and the reference voltage generation circuit (5) respectively; the current IBIAS generated by the pre-bias circuit (1) is output to the positive and negative temperature coefficient current generation circuit (3); currents I1 and I2 generated by the positive and negative temperature coefficient current generation circuit (3) are output to the reference voltage generation circuit (5); and simultaneously, the voltage VBE generated by the positive and negative temperature coefficient current generation circuit (3) is converted into a current I3 by the voltage / current conversion circuit (4) and is output to the reference voltage generation circuit (5); and the reference voltage generation circuit (5) outputsthe reference voltage VREF. The band-gap reference voltage source is high in rejection ratio and excellent in temperature stability and can be applied to an integrated circuit with wide input and high precision.

The invention discloses a band-gap reference voltage source with the curvature compensation function. The band-gap reference voltage source with the curvature compensation function comprises a one-order temperature compensation circuit, a curvature compensation circuit and a band-gap reference voltage generating circuit, wherein the one-order temperature compensation circuit is used for generating same-order current irrelevant to temperature, the curvature compensation circuit is used for generating current with a high-order temperature characteristic and superimposing the current with the high-order temperature characteristic and the same-order current irrelevant to temperature so that the current irrelevant to temperature can be generated, the band-gap reference voltage generating circuit is used for transmitting the current irrelevant to temperature to the output end and converting the current into voltage, the one-order temperature compensation circuit is connected with the curvature compensation circuit, and the curvature compensation circuit is connected with the band-gap reference voltage generating circuit, and the one-order temperature compensation circuit, the curvature compensation circuit and the band-gap reference voltage generating circuit jointly form the band-gap reference voltage source. Through the band-gap reference voltage source, the accuracy of compensating current can be effectively improved, the temperature drift coefficient of output reference voltage is reduced, and therefore the temperature stability of the output reference voltage can be improved.

A band-gap reference voltage is developed by a phase-clocked band-gap circuit including a single PN junction through which first and second constant currents are alternately directed. A current proportional to absolute temperature is selectively added to one of the first and second constant currents to curvature-compensate the developed band-gap reference voltage. The band-gap circuit is calibrated at any desired temperature by interrupting the curvature compensation current and trimming the one constant current to bring the un-compensated band-gap reference voltage into correspondence with a nominal band-gap voltage functionally related to the calibration temperature and circuit component values.

The invention provides an antenna array SAR polar coordinate overlapped sub-aperture imaging method for a two-dimension SAR imaging system consisting of array antennas. The method is suitable for an array antenna radar system of which the transmitting signal is a Chirp signal or an SFCW signal. The method comprises the steps of completing range frequency matched filtering, carrying out Polar Formatting transform to represent an observation scene object in a polar coordinate system, completing range imaging through range Fourier transform, and then completing high-precision wave-front curvature compensation and azimuth imaging processing through overlapped sub-aperture processing in the azimuth direction so as to obtain a high-precision two-dimension image.

An IR microscope (1) is constituted such that, in an optical viewing mode in a beam path of visible light (VIS-R, VIS-T), a first intermediate focus (ZW1) is imaged onto a flat detector surface (15a) of a camera. The IR microscope (1) is constituted such that, in the beam path of the visible light (VIS-R, VIS-T), the first intermediate focus (ZW1) is imaged onto a second intermediate focus (ZW2), and, in the second intermediate focus (ZW2), a Mangin mirror (11) is disposed that corrects a field curvature of the Cassegrain objective (4). The invention provides an IR microscope in which the field curvature generated by the Cassegrain objective is corrected in a simple manner in the optical viewing mode when detection is performed using a flat detector and without restricting the spectral range of the IR microscope.

The invention relates to an electronic device with a bandgap reference generator including a first path with series connection of a first bipolar transistor, a first resistor and a second resistor, and a second path with series connection of a second bipolar transistor and a third resistor. The first and second paths are supplied current via a common node through a fourth resistor controlled by an amplifier sensing voltage drops within the first and second paths. A curvature compensation stage compensates for a variation of base emitter voltage of the bipolar transistors by drawing a compensation current from the common resistor node.

The invention discloses a polar coordinate wave-front curvature compensation method of a synthetic aperture radar based on digital spotlight, comprising the following steps: (1) realizing segmentation of irradiation areas of radar beam by processing of improved digital spotlight and pre-filtering; (2) carrying out imaging processing on subwave beam data by utilizing a polar format algorithm (PFA), and realizing focused imaging of subscenes; and (3) carrying out seamless splicing on the images of the subscenes. By utilizing the polar coordinate wave-front curvature compensation method, the existing digital spotlight method is improved, repeated coarse focused imaging to the echo data (large data quantity) of the initial radar is avoided, and is replaced with the one-time coarse focused imaging of the initial data and the inverse imaging of a plurality of subwave beams (small data quantity), and the calculating efficiency of an algorithm can be obviously improved when multi-beam segmentation is carried out. Due to adoption of the polar coordinate wave-front curvature compensation method, the problem that the prior art can not compensate wave-front curvature errors of the pole format algorithm accurately under the large maneuvering condition of a radar platform can be solved.

This invention belongs to band gap basic power field, which is characterized by adding two current branches on current power and dividing two triodes integration injection current and fetch current to change their temperature properties and to change output basic voltage temperature property to achieve three basic voltage local maximum points in whole work range to make the output voltage basic temperature first degree derivative as zero.

The present invention discloses a bandgap reference circuit for implementing the high-order temperature compensation of a diode by means of an MOS transistor. The bandgap reference circuit comprises afirst-order bandgap reference circuit, a high-temperature region temperature curvature compensation circuit, a low-temperature region temperature segment compensation circuit and a startup circuit. According to the bandgap reference circuit, a drain electrode and a substrate of a PMOS transistor in which a source electrode, the drain electrode and a gate electrode are in short connection with oneanother form a forward end and a reverse end of the diode respectively; by utilizing negative temperature coefficient voltage VCTAT generated by the drain-substrate voltage of the PMOS transistor inwhich the source electrode, the drain electrode and the gate electrode are in short connection with one another and positive temperature coefficient voltage VPTAT generated by the difference of two drain-substrate voltages of the PMOS transistor in which the source electrode, the drain electrode and the gate electrode are in short connection with one another, the negative temperature coefficient voltage VCTAT and the positive temperature coefficient voltage VPTAT are weighted to obtain first-order bandgap reference voltage, high-temperature region temperature curvature compensation voltage VNL1 and low-temperature region temperature segment compensation voltage VNL2 are introduced to the first-order bandgap reference circuit to obtain bandgap reference voltage with a low-temperature coefficient, and therefore the bandgap reference circuit for implementing the high-order temperature compensation of the diode by means of the MOS transistor is obtained.

The present invention is in related to a miniature surface plasmon resonance waveguide device with sinusoidal curvature compensation and at least comprises: a substract, a waveguide structure, a sensing film layer and a cover layer, wherein the waveguide structure is configured with the function of sinusoidal curvature compensation and installed above the substract, further that, the waveguide structure includes a light input port and a light output port; the sensing film layer is on a special region of the waveguide structure, the special region is a sensing region; the cover layer is upper than the substract and has an opening. By means of the optimal curve figure of the sinusoidal curvature compensation, attenuation of light energy can be minimized while in propagation, and allows the input and output of the light on the same side of the device.

The invention relates to an exponential compensation-based low-temperature-drift high-power-source rejection ratio band-gap reference circuit. The circuit comprises a pre-voltage stabilization module,a pre-voltage stabilization starting module, a band-gap reference core module and a band-gap reference core starting module; the band-gap reference core module is used for generating a reference voltage; a fifteenth PMOS transistor of a common source connection method forms a beta help structure, and therefore, the problem of excessively large error induced by base current due to a too small betavalue in a CMOS process is avoided; the high-order curvature compensation structure of the reference voltage is embedded into the beta help structure through a ninth resistor R9, so that the temperature drift coefficient of a reference output voltage is remarkably reduced; the band-gap reference core starting module is used for separating the band-gap reference core module from a degeneracy point; the pre-voltage stabilization module is used for generating local voltages for supplying power for the band-gap reference core module and the band-gap reference core starting module; by means of a self-adaptive driving structure, the driving capability of a pre-voltage stabilization structure is guaranteed, and the power supply rejection ratio of the reference output voltage is effectively improved; the pre-voltage stabilization starting module is used for separating the pre-voltage stabilization module from a degeneracy point.

The invention provides a high-order curvature compensation reference voltage source with the modifying function. The high-order curvature compensation reference voltage source at least comprises a first current generating circuit, a first resistance circuit, a curvature compensation circuit and a second resistance circuit, the first current generating circuit is used for generating a one-order compensation current based on a transistor and a resistor, the first resistance circuit comprises a first adjustable resistance network and is connected with the first current generating circuit in series so as to produce a reference voltage, the curvature compensation circuit is used for generating a high-order compensation current to the first resistance circuit so that curvature compensation can be achieved, and the second resistance circuit comprises a second adjustable resistance network and is used for dividing the reference voltage so that the reference voltage can be output. The temperature characteristic curve of a voltage reference source can have a plurality of extreme values in the whole working temperature range, and the precision of the voltage reference source is obviously improved.

A preparation method includes:acquiring a frame of reference of ophthalmic lens defined at least by a first centering point and by a first orientation direction;acquiring a frame of reference of the rim of the eyeglass frame defined at least by a second centering point and a second orientation direction;acquiring a longitudinal profile representative of the shape of the rim and identified in the frame of reference of the rim;acquiring a curvature parameter or a curvature compensation parameter relating to the camber of the eyeglass frame; andputting the two frames of reference into coincidence, by positioning the two centering points relative to each other and by orienting the two orientation directions relative to each other as a function of the curvature parameter or the curvature compensation parameter so as to define the position and the orientation of the longitudinal profile in the frame of reference of the ophthalmic lens.

The invention discloses a low-power-consumption band-gap reference circuit with high-order curvature compensation. The band-gap reference circuit comprises a starting circuit, a biasing circuit, an operational amplifier circuit, a generation circuit and a high-order temperature compensation circuit. According to the band-gap reference circuit, compensation is performed on high-order temperature characteristics of emitter junction voltages of PNP-type transistors according to an inherent exponential relation among sub-threshold regions of MOS transistors; under the condition of only adding twoimage currents, compared with a traditional first-order low-voltage band-gap reference circuit, the band-gap reference circuit is low in power consumption, and the level of the power consumption is nanowatt; by the adoption of a curvature compensation technology, the temperature drift coefficient of an output reference voltage is relatively small and is 20ppm / DEG C or below; and when the ambient temperature changes within the range from -20 DEG C to 80 DEG C, the temperature drift is 4.6ppm / DEG C, and the power consumption of the whole band-gap reference circuit is lower than 1uw.

The invention discloses a reference voltage circuit. The reference voltage circuit comprises a first-order compensation circuit for producing current irrelevant to first-order temperature, a curvaturecompensation circuit connected with the first-order compensation circuit and used for producing current having high-order temperature characteristics and superposing the current and the current irrelevant to first-order temperature to produce current irrelevant to high-order temperature, and a voltage generating circuit connected with the curvature compensation circuit and used for generating reference voltage according to the current irrelevant to high-order temperature, wherein the curvature compensation circuit comprises a current source and a first audion, the current source and the firstaudion are matched to produce current having high-order temperature characteristics, and the current source is a current source having a zero-temperature coefficient. In this way, high-order temperature compensation can be achieved, a circuit structure is simple and easy to achieve.

The invention relates to a bandgap voltage generator with curvature compensation, which comprises PMOS pipes P1-P4, transistors Q1-Q4, resistors R1-R4 and an amplifier, wherein the source electrodes of the PMOS pipes P1-P4 are connected with a power supply, the drain electrode of the PMOS pipe P1 is connected with the emitter electrode of the transistor Q1 and the negative input end of the amplifier, the grid electrodes of the PMOS pipes P1-P4 are all connected with the output end of the amplifier, and the collector electrodes and the base electrodes of the transistors Q1-Q4 are all grounded;the drain electrode of the PMOS pipe P2 is connected with the positive input end of the amplifier and is connected with the emitter electrode of the transistor Q2 by the resistor R1; the drain electrode of the PMOS pipe P4 is connected with the emitter electrode of the transistor Q4 and is connected with the drain electrode of the PMOS pipe P3 by the resistor R4; the drain electrode of the PMOS pipe P3 is connected with the emitter electrode of the transistor Q3 by the resistor R2 and is grounded by the R3; and the output end of the bandgap voltage generator is connected with the drain electrode of the PMOS pipe P3. The bandgap voltage generator provided by the invention can work under the voltage of 1V and can enhance the temperature coefficient obviously.

The invention discloses a high-precision negative-voltage sectional compensation band gap reference voltage source circuit, and relates to the technical field of integrated circuit voltage regulators. The voltage source circuit comprises a starting circuit, an auxiliary reference current generation circuit with exponent compensation, a first sectional compensation current generation circuit, a second sectional compensation current generation circuit and a negative-pressure sectional curvature compensation band gap reference voltage output circuit. The voltage source circuit conducts curvature compensation on a bipolar two-tube negative-pressure band gap reference circuit through exponent compensation and twice sectional compensation of different high-temperature segments, high-precision negative-voltage reference voltage output is guaranteed, and the power supply rejection ratio of a negative reference source is increased through a negative feedback loop.