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In this brief, a high sensitivity measuring system for capacitive sensor to detect moving target is presented. It mainly consists of a capacitance measuring circuit and a dc-blocking circuit. The capacitance measuring circuit is used to convert a capacitance to a dc voltage and the dc-blocking circuit is employed to extract the voltage variation. The experimental results show that when the measured capacitor is between 1 pF to 7.5 pF, the sensitivity is 3.53 V/pF, the linearity error is 6.13%, the SNR increases from 26.6 dB to 57.7 dB, the resolution is 3.1 fF and the time delay is about $4\,\mu \text{s}$ . Comparing to five other common capacitance measuring circuits, the proposed one offers plain design, high sensitivity, and fast speed. Simulation results show that the proposed dc-blocking circuit has short time delay and unattenuated output. Moreover, as demonstrated by system tests, the proposed measuring system is qualified for capacitive sensor for detection of moving target with different speeds.

The paper presents an operational transconductance amplifier (OTA) with low transconductance (0.62&ndash, 6.28 nS) and low power consumption (28&ndash, 270 nW) for the low-frequency analog front-ends in biomedical sensor interfaces. The proposed OTA implements an innovative, highly linear voltage-to-current converter based on the channel-length-modulation effect, which can be rail-to-rail driven. At 1-V supply and 1-Vpp asymmetrical input driving, the linearity error in the current-voltage characteristics is 1.5%, while the total harmonic distortion (THD) of the output current is 0.8%. For a symmetrical 2-Vpp input drive, the linearity error is 0.3%, whereas THD reaches 0.2%. The linearity is robust for the mismatch and the process-voltage-and-temperature (PVT) variations. The temperature drift of transconductance is 10 pS/&deg, C. The prototype circuit was fabricated in 180-nanometer CMOS technology.

This paper proposes a 16-bit 6-channel high-voltage successive approximation register (SAR) ADC with an optimized 5 + 5 + 6 segmented capacitor array. The lower 10 bits of the capacitor array are all composed of unit capacitors without any calibration unit. Without calibration, the lower 10 bits of the capacitor array can ensure 10-bit conversion accuracy. Every of the upper 6 bits of the capacitor array contains a linearity calibration unit. The linearity error of the upper 6 bits is calibrated by the linearity calibration unit. The 16-bit is manufactured by a $0.6~\mu m$ standard COMS process, and the total chip area of 6-channel ADC including pads is 6.6mm $\times6.6$ mm. As for single channel SAR ADC, the area is 0.9mm $\times2.0$ mm. The measurement results show that the effective conversion accuracy of the SAR ADC reaches 13 bits by using novel differential nonlinearity (DNL) and integral nonlinearity (INL) calibration methods. The power is 80mW, corresponding to a Figure of Merit (FOM) of 48 pJ/conv.-step.

A cross-capacitance liquid level sensor is based on the principle of cross capacitance. This study designed a new single-tube cross-capacitance fuel-level sensor. The fuel-level measurement model is established for a single-tube cross-capacitive sensor, and the relationship between the measured liquid level and sensor output capacitance is derived. The characteristics of the sensor were tested experimentally. The experimental results demonstrate that the linearity error of the liquid-level sensor of the single-tube calculation for the spacecraft is &plusmn, 0.48%, the repeatability error is &plusmn, 0.47%, and the hysteresis error is &plusmn, 0.68%. The cross-capacitive fuel-level sensor developed in this study can be used in the fuel tank of spacecrafts owing to its low weight and high precision.

This paper presents an approach to seeker-azimuth determination using the gyro rotor and optoelectronic sensors. In the proposed method, the gyro rotor is designed with a set of black and white right spherical triangle patterns on its surface. Two pairs of optoelectronic sensors are located symmetrically around the gyro rotor. When there is an azimuth, the stripe width covering the black and white patterns changes. The optoelectronic sensors then capture the reflected optical signals from the different black and white pattern stripes on the gyro rotor and produce the duty ratio signal. The functional relationship between the measured duty ratio and the azimuth information is numerically derived, and, based on this relationship, the azimuth is determined from the measured duty ratio. Experimental results show that the proposed approach produces a large azimuth range and high measurement accuracy with the linearity error of less than 0.005.

Clamp-on ultrasonic flowmeters geometry includes four different materials in the ultrasound propagation path: wedge, coupling material, pipe and liquid. In this case, oblique incidence ultrasonic beam generated by the emitter transducer is split into several paths caused by multiple reflections in pipe wall or because of propagation mode conversion at interfaces. These multiple paths are recombined at the reception transducer aperture, producing a single signal whose amplitude and phase depend on which proportion each path contributes. The objective of this paper is to quantify this phenomenon and analyses the implications it has on the accuracy of Clamp-on ultrasonic flowmeters as a function of the fluid that flows inside the pipe. According to simulations, based on 2D ray tracing model and experimental measurements, the variations in the recombination signal at the reception transducer produces a linearity error that in case of the installation under test, Z-mode transducers configuration on PVC pipe, could reach a value of 3.2%.

© 2017 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This article analyses and explains the implications that dispersive materials have over the linearity in flow measurement when a Clamp-on ultrasonic flowmeter is used. This is of capital importance because dispersive materials are commonly used in the manufacture of transducer wedges and pipes. The evaluation of this phenomenon has been tested by experimental measurement. The used setup consisted of a water flow calibration facility where a commercial Clamp-on ultrasonic flowmeter was installed on it and its flow measurement was compared with a reference flowmeter. Two experiments have been conducted. A first experiment was performed to evaluate only the effect produced by the fact that the transducer wedge is made of dispersive material. For this reason, an ultrasonic flowmeter was installed on a pipe made of non-dispersive material, in this case, an INOX pipe. Linearity error introduced by the wedge was below 1%. This error complies with the accuracy specification of the ultrasonic flowmeter given by the manufacturer (±1.5%). Finally, a second experiment consisted of installing the ultrasonic flowmeter on a dispersive pipe (PVC pipe) in order to measure the worst condition (both materials, wedge and pipe, were dispersive). Under this condition, the linearity error was increased until it reaches a value of 6.4%. Moreover, in case of a dispersive material pipe, the bigger the pipe thickness is, the bigger non-linearity error is reached.

as everyone knows, conditioning F2N2(Feed Forward Neural Network) in many ways, but ways, but has so far failed to completely solve the "convergence not quickly" and "convergence is not robust"of these two problems, thus affecting the application of F2N2. Aiming at this problem, pro this paper puts forward a new method of processing and application of F2N2, the method of flexible BPNN (Back Propagation Neural Network) algorithm and hierarchical optimization algo-rithm as a whole, each layeris independent rights attached to the conditioning process, carefully con-structed F2N2objective function is non linear series based on the description, not only can the optimization of each layer of the weight problem is simplified to a linear problem, but also can effec-tively controlthe linearity error. This paper provides several examples of application of F2N2automa-tic detection, the results of application show that, this method is superior to other methods.

In this brief, a new low-voltage CMOS circuit to produce current-mode exponential characteristics is proposed. MOSFET transistors in weak-inversion region and translinear principle for the temperature cancellation were used. The functionality of the proposed design confirmed with 0.35 μm CMOS process technology using ±0.75 V supply voltage. Results demonstrate the theoretical analysis and verify the efficiency of the proposed structure compared with previously reported designs. Around 96 linear-in-dB output current range is achieved with ±0.5 dB linearity error over normalized input range from -5.75 to 5.75. The maximum deviation in the output current is ±1.27 and ±3.35 dB due to 100 °C temperature variations and ±10% supply voltage fluctuation, respectively.

This paper explains and demonstrates how an atomic force microscope (AFM) is working and how can be improved the measurements realized with this system. At the begining of the paper is a complex presentation of AFM and its improvement with capacitive sensors. Starting from the obtained information, we studied the influence of quality and linearity error of sensors to characterize surfaces using atomic force microscopy. We used the device that had sensors with a linearity error of 0.1%. For another set of measurements we used sensors with linearity error of 0.01%. Experiments realized on CoCrMo and Ti6Al4V materials surfaces demonstrated that the accuracy of sensors, respectively, the linearity error, from the measurement system has an important influence.

The bending sheet metal inevitably exist bending errors including angle error, linearity error and length error of sideline for reasons that the structure of press brake, the manufacturing precision of press brake and mould and the inhomogeneous characteristics of processed sheet metal. The processing errors of sheet metal can affect the assemblage, increasing subsequent repair to the mold and forming calibration, extending the product development cycle, restricting the further promotion and application of bending forming, especially on the forming high strength and high spring-back sheet metal. The PBH110-3100 CNC press brake in Jiangsu Yawei Co.Ltd. is studied to increase the bending precision of press brake in this study. The bending errors in press break are analyzed in depth according to the elastic mechanics theory, and the rule that the manufacturing precision of press brake affect the press precision is educed. The analysis results have real significance on improving the press precision and reliability of press brakes.

A new kind of straightness error measurement system based on laser interference is developed. High stability He-Ne laser beam which is collimated and broadened is cast on wedge-shaped glass plate, on which back and front the light reflects and interfere. The angle of the guide and target would be changed when the motion of the target is along the guide, if there is linearity error existing in the guide. So interference stripes would be moved by the changed angle of the guide and target. In this way the straightness error of the guide is transferred to the displacement of the interference stripes. Then interference stripes are tested by photoelectricity sensor and deviation of the laser beam is acquired. The comparison tests and repeated tests show that the straightness error is 623.103μm when the tested long guide is 50 meters long.

This paper presents a new current-mode squaring circuit. The design is based on MOSFETs translinear principle in strong inversion. A new compensation technique to minimize the second order effects caused by carrier mobility reduction in short channel MOSFETs is proposed. Tanner T-spice simulation tool is used to confirm the functionality of the proposed design in 0.18 µm CMOS process technology. Simulation results indicate that the maximum linearity error is 1.2 %; power consumption is 326 µW and bandwidth of 340 MHz.

A long rail straightness measurement method is given for the portable laser alignment measurement system which is based on laser shearing interference fringes. Through theoretical derivation, mathematical model is set up between the laser phase differential linearity error and shearing interferometry. Large numbers of experiments have verified correctness of long rail straightness measurement method, analyzed the cause of error and provided ways for error reduction.

This paper presents an ultra low power differential voltage-to-frequency converter (dVFC) suitable to be used as a part of a multisensory interface in portable applications. The proposed dVFC has been designed in 1.2-V 0.18-μm CMOS technology, and it works properly over the whole differential input range (0.6 ± 0.6 V) providing an output frequency range of 0.0---0.9 MHz. The system has been tested for temperature variations from Â?40 to +120 °C and supply voltage variations of up to 30 %, being the maximum linearity error in the worse case of 0.017 %. Simulations against common mode voltage variations show a deviation in the output frequency of 0.4 %. This dVFC has power consumption below 60 μW, and it includes an enable terminal that sets the system in a sleep mode (180 nW) while no conversion is request. The dVFC occupies an active area of 250 μm A— 150 μm.

For the dispersion problem of the widespread sensors in the R & D process of measuring instruments, this paper proposes a practical method for the automatic calibration of linearity error. Meanwhile, it takes the pressure sensor as an example to describe different calibration methods such as using the hardware, the combination of software and hardware, using the software.

The operating performance of micro-gyroscope may be easily influenced by various factors, which changes the dynamic response accordingly. Generally, the influences can’t be quantified because of the complexity, and the accurate sensitivity and linearity measuring of micro-gyroscope meets enormous difficulties. In order to accomplish corresponding measuring and analysis accurately and efficiently, input excitation waves are designed based on mathematical analysis of the measuring principles and vibration response, and each measuring of sensitivity and linearity can be analyzed in a single test. In this way, the influences from manual operation and variation of measuring environment are well eliminated, and some key parameters of the dynamic response are obtained, such as sensitive voltage, response function, linearity error, etc. In addition, problems about imbalance in double drive vibration, design of the minimum excitation voltage and evaluation of the measuring error are also described. Therefore, some important references are provided for subsequent design, experiment and engineering application.

This article explains how a multi-frequency ultrasonic beam path is split due to passing through dispersive materials and the implications that it has in flow measurement using a Clamp-on ultrasonic flowmeter. The importance of knowing this phenomenon is because dispersive materials are commonly used in the manufacture of transducer wedges and plastic pipes. Splitting of the ultrasonic beam path occurs when the incident angle is not normal to the surface of the pipe and a coupling wedge is necessary. The diffraction angle is produced at the boundaries among materials with different propagation velocities (according to Snell’s law), and furthermore, in dispersive materials, the propagation speed depends on frequency. Therefore, when the excitation signal contains several frequential components, each frequency travels with a different velocity. Under this circumstance, different diffraction angles are produced for each frequency at the boundaries between materials. As a result of splitting the path, the ultrasonic beam widens and the reception transducer aperture becomes too small to receive all the frequential components contained in the ultrasonic beam. Thus, when the ultrasonic beam is carried by the liquid flowing inside the pipe, the reception transducer receives different frequential contributions, producing change in its spectral composition. As a consequence of the mixing of these frequencies, the reception signal is modulated in phase and amplitude. Moreover, modulation will change as a function of frequential composition that is combined at the reception transducer. This is the origin of the linearity error in Clamp-on ultrasonic flowmeters.

Crack and strain detecting is an important part of Structure Health Monitoring for aircrafts in fatigue environment. A signal conditioning circuit of a new strain-crack detecting system is developed in this paper. This circuit can deal with both intelligent coating sensor and strain gage, which have a great different original resistance between the two kinds of sensors. Comparing to the Wheatstone Bridge, when the strain is being detected, the new circuit gets rid of the influences of the lead-wires and decreases the wires’ number. The principle and the constitution of the circuit are introduced. And the circuit’s performances are demonstrated by a series of experiments. The linearity error is small and the stability is good.

An analog multiplier driven by a single supply voltage is proposed. Some improvements are introduced so as to get a higher performance. The proposed analog multiplier can work precisely in four quadrants with a very small THD. An added OTA keeps the linearity error of the circuit smaller than 1%. The presented multiplier is designed on the 0.6 μm BCD process and the simulation results by HSPICE shows a perfect performance. It can be used in any system that requires a high performance analog multiplier.

A bridge resistance deviation-to-period (BRD-to-P) converter is presented for interfacing resistive sensor bridges. It consists of a linear operational transconductance amplifier (OTA) and a current-controlled oscillator (CCO) formed by a current-tunable Schmitt trigger and an integrator. The free running period of the converter is 1.824ms when the bridge offset resistance is 1kΩ. The conversion sensitivity of the converter amounts to 3.814ms/Ω over the resistance deviation range of 0-1.2Ω. The linearity error of the conversion characteristic is less than ±0.004%.

Linearity is a very important parameter for seamless steel pipes. A real-time and on-line visual measurement system for seamless steel pipe linearity is presented. The system consists of several structured-light visual sensors. Each sensor can achieve the coordinate of the center of partial steel pipe in its local coordinate system. Through global calibration, all coordinates measured can be transformed into an integrated coordinate system. The linearity error of steel pipe can be assessed. This method can fulfill 100% on-line and real-time linearity measurement. A pair structure-light sensor is designed to improve accuracy and a suspension-wires method for sensor calibration and global calibration is used. Through experiments, it shows that the method not only meets the need of precise calibration but also significantly improves the efficiency and feasibility.

A confocal laser displacement sensor using a micro-machined varifocal mirror is reported. The focal length modulation is a key function of the confocal sensor. The mechanism of the focal length modulation determines the measurement speed and range. Here, we propose application of the micro-machined varifocal mirror for the modulation. The varifocal mirror can realize faster modulation, small size, and low energy consumption for the confocal displacement sensor. The electrostatically actuated varifocal mirror made by single crystalline silicon is used. The working distance of the sensor is designed to be 31 mm. The actuating range at 7 kHz is 310 μm. The linearity error in the actuating range is from -1.1% to 1.2%.

In the paper design and analysis of an off-axis absolute rotary position sensor setup is described that is intended to use in realizing accurate and reliable absolute angle measurement to be applied in precise control of electric (e.g. vehicle) drives. A solution of using magnetic position sensing elements in combination with two differently magnetized ferromagnetic rings is presented. By assuming a specific setup the algorithm of determining absolute position is given, as well by analyzing the measurement errors, a compensation scheme is elaborated. By using this scheme the linearity error of the sensor setup can significantly be reduced without applying any expensive equipment.

A single width NIM module that includes eight channels TAC (time-to-amplitude converter) and QAC (charge-to-amplitude converter) is introduced in the paper, which is designed for the large neutron wall detector to measure charge (energy) and time interval simultaneously [1]. The module mainly adopts a high precision gated integral circuit to realize TAC and QAC. The input range of TAC is from 30 ns to 1 us, and the input range of QAC is from 40 pC to 600 pC. The linearity error of TAC is lower than 1.28 %, and the time resolution of TAC is less than 0.871 %. The linearity error of QAC is lower than 0.81 %, and the resolution of QAC is better than 0.936 %.

This paper presents a new ultra-low-voltage current-mode four-quadrant analog multiplier. A floating-gate technique is used to provide operating at a supply voltage of 0.75 V for the proposed circuit. PSPICE simulators using 0.18 µm TSMC CMOS process are used to show the workability of the multiplier. Simulation results show that the circuit has a linearity error of 1.5 % for the input current 8 µA, total harmonic distortion of 0.96 % for the input current 8 µA peak and quiescent power consumption of 19.9 µW.

A design of the resistive mirror-based voltage-controlled resistor (VCR) in bipolar technology is presented. The resistive mirror has been designed using the current-mode signal processing. The modification of the translinear reduction of the "log-antilog" analog multiplier/divider working with currents has been used. Simulation results show the linearity error less than 0.4% in a wide operating range.

A model of the linear R-2R ladder digital-to-analog converter (DAC) is developed in terms of the ratios of the effective resistances at the nodes of the ladder. This formulation demonstrates clearly why an infinite number of different sets of resistors can produce the same linearity error and shows how this error can be reduced by trimming. The relationship between the weights of the bits and the resistor ratios suggests appropriate trimming, design, and test strategies.

A novel voltage-tunable, low-voltage linear CMOS transconductor design is described. The design is based on the improvement of the cross-coupled pairs. SPICE simulation results show that using BSIM models, MOSIS 2-μm n-well process parameters and a power supply of ±2.5 V, the linearity error is less than 0.4% over a differential input voltage range of ±1.2 V. The THD for a differential input voltage of 1\,\hbox {\it V}_{\it {pp}} at 1 kHz is 1.3%.

The present paper describes a high-precision angle sensor and a new method for calibrating precision angle sensors absolutely without the use of any accurate reference instruments. Two angle sensors with compensating devices which compensate thermal drift of the light source are developed and calibrated by themselves. The repeatability error of the evaluated mean sensitivity was improved to 0.01% by the compensating device. The repeatability of the calibrated linearity error was reduced to 0.025 s (arc). This paper also describes a new differential method that can calibrate simultaneously the dividing errors of a polygon mirror and angular profile of polygonal surfaces by using the developed angle sensors. Calibration of a 24-sided polygon mirror showed the repeatability error of dividing angle and angular profile to be approximately 0.2 s (arc).

We developed highly accurate optical magnetic field sensor probes. New probe-type sensors 5 mm in width were designed, using a confocal optical system with two drum-shaped ball lenses. BiRIG films were prepared by the LPE method. We found a new garnet composition, Bi0.98Gd0.92La0.03Y1.07Fe4.72Ga0.28O12, that showed high temperature stability for sensitivities less than 2.0% from - 20°C to +80°C. The linearity error of the sensor output was obtained within 1.0% for alternating magnetic fields from 5.0 Oe to 450 Oe. We also developed optical current transformers (OCTs), using this sensor and a permalloy magnetic core with a 6 mm air gap. The sensitivity of the new OCTs is about four times higher than that of our previous ones. The OCTs showed high performance in practical use.

This paper presents a new current-mode squaring circuit. The design is based on MOSFETs translinear principle in strong inversion. A new compensation techniques to minimize the second order effects caused by carrier mobility reduction in short channel MOSFETs is proposed. Tanner T-spice simulation tool is used to confirm the functionality of the proposed design in 0.18μm CMOS process technology. Simulation results indicate that the maximum linearity error is 1.16 % and the power consumption is 331μW.

This paper presents a new self-calibration method for calibrating the linearity error of two dimensional displacement sensors. By using this method, the linearity error can be calibrated accurately without using any other accurate calibration reference. This method utilizes the special feature of the two dimensional displacement sensor so that the self-calibration can be realized easily and effectively. In this paper, the proposed method is applied to calibrate two dimensional position-sensing devices (PSD). A calibration system, which consists of only a laser diode, an X-Y stage and a two dimensional PSD, is constructed. The laser diode is placed on the X-Y stage, and the PSD is fixed spatially. The laser beam from the laser diode is used to scan two-dimensionally the surface of the PSD by moving the X-Y stage. Two kinds of PSD were calibrated using the calibration system, and the experimental results confirming the effectiveness of the proposed method are presented.

We developed highly accurate optical magnetic field sensors. The sensor optical system has a confocal optical system using ball lenses. Bi-substituted rare earth iron garnets were prepared by the LPE method for use as Faraday rotators. We found that a new garnet composition, Bi1.14Gd0.57La0.02Y1.27Fe4.53Ga0.47O12, showed stable temperature characteristics of the sensitivity; The temperature dependence of the sensor output was less than 2.0% from -20°C to +80°C. We also improved the linearity error in the small magnetic field by using the film thickness dependence of the wall coercive force. The linearity error of the sensor output was within 1.0% for alternating magnetic fields from 3.0 Oe to 420 Oe. The sensors achieved high performance with regard to the linearity and the temperature characteristics.

A new CMOS four-quadrant multiplier using active attenuators is presented. Simulation results show that for a power supply of ±5 V, the linear range is over + 1 V with the linearity error less than 0-83%. The total harmonic distortion is less than 1% with an input range up to ± 1 V. The simulated —3dB bandwidth is about 5 MHz. Experimental results show that the linear range is within ± 1 V. The proposed multiplier is expected to be useful in analogue signal processing applications.

A device is described to measure balance including side-to-side, forward-to-back sway and the centre of gravity of the body during standing and sitting in a chair or wheelchair. The device incorporates a 2-dimensional reach test which can assess the degree of disability in central core balance when reaching for an object to either side or in the forward direction. The device has a weight measuring linearity error of less than 2%, an effective frequency response from DC to 50 cycles per second, and the correlation between the true position of a weight and the measured position through its sensors is 0.98. The device measures body sway in the forward and lateral directions and tremor. This design should be quite useful in rehabilitation to measure stability of the body and its relation to core strength and level of disability. This is especially important before and after rehabilitation to quantify functional outcomes in a time when insurance reimbursement demands quantifiable improvement.

An accurate goniometer was constructed being a part of a system devoted to the measurement of reflecting properties of surfaces. By it a surface of the sample under test can be arbitrarily oriented with respect to the observing direction and the direction of the shooting light beam. The high performances (revolution angle uncertainty equal to 0.1deg) required as specifications for the construction are checked. Particular attention is used to analyze the orthogonality among the revolution axes of each goniometer components and their convergence in the goniometer center. The linearity error of each revolution motion is measured by using a differential method. It proves to be effective to highlight the small linearity deviation and to verify the uncertainty declared by the manufacturer

This paper proposed an ultra low-voltage low-power all CMOS exponential V-I converter with tunable input and output ranges. The Taylor series expansion is used for realizing the exponential characteristic. The simulations, based on a 0.25 mum CMOS process, show a 20 dB linear output current range and a 15 dB-linear range with the linearity error less than plusmn 0.5 dB at 1.25V supply voltage. The average power consumption is less than 80 muW

A 6-bit 1.6 GS/s CMOS flash ADC using reversed-reference dummy method is demonstrated in a standard 0.18-μm CMOS process. The proposed method improves linearity error at the boundary of offset averaging networks. The prototype circuit exhibits an INL of +0.32/-0.28 LSB and a DNL of +0.28/-0.28 LSB. The SNDR and SFDR achieve 32 and 44 dB at 1.6 GS/s for Nyquist input frequency. The ADC consumes 350 mW at 1.8 V supply and occupies an active chip area of 0.46 mm2.

A capacitive gap sensor with high-performance has been developed. The sensor is characterized by a sensor electrode having a guard electrode, a phase compensated AC-DC converter and a digital linearizer to accomplish the compatibility of high S/N with high speed of response. A resolution of order 10nm, a high frequency response of about 10kHz at the phase-delay of 45° and a wide measurement range of 100μm with 0.03% linearity error are realized by the sensor with the above mentioned features. It is estimated that the expanded uncertainty(k=2) of the sensor is 20.6nm.

A biaxial MEMS raster scanner is developed for laser scanning displays. We discuss microfabrication, packaging, and design aspects, and how to minimize power consumption and linearity error by optimizing the vertical scanner resonant frequency and drive waveform.

A four-quadrant CMOS analogue multiplier is presented. Experimental results show that the multiplier has a dynamic input range, exceeding 60% of the power supply voltage (/spl plusmn/0.5 V), and the linearity error is less than 0.07% at the maximum input range. The simulated maximum power dissipation for the multiplier is 2.83 mW.

A 10-b video CMOS D/A converter for low supply voltage has been developed. Nonsaturating transistors and a new switching scheme are introduced to current sources in the D/A converter, which operates at 50 MS/s with a 2.7 V power supply. Integral linearity error and differential linearity error are less than 0.5 LSB and 0.25 LSB, respectively. The dependence of the linearity error on full-scale voltage is plotted. Device characteristics are summarized. >

A new wide range BiCMOS transconductor and a multiplier were presented. Simulation results show that for a power supply of /spl plusmn/5 V, the linear input range of this transconductor is over /spl plusmn/4 V with the linearity error less than 2%. The total harmonic distortion is less than 0.69% with input range up to /spl plusmn/3 V. Its -3 dB bandwidth is 54 MHz. A new BiCMOS multiplier is also presented. Its linear input range is over /spl plusmn/2.5 V with the linearity error less than 1%. Its -3 dB bandwidth is over 60 MHz. The proposed circuits are expected to be useful in analog signal-processing applications.

This paper reports about the design and experimental results of the vibrating micromachined gyroscope that is designed to mechanically decoupled structure with optimized two gimbals. The gyroscope is characterized by a low linearity error of less than 0.5744% full scale for a measured range of /spl plusmn/150 deg/sec under vacuum pressure of 4 mTorr. The equivalent noise density is 0.002 deg/sec//spl radic/Hz and the equivalent noise rate is less than 0.005 deg/sec. The bias is stabilized between equivalent rate of less than 0.02 deg/sec.

An integrated capacitive surface micromachined pressure sensor for high temperature applications was developed and characterized to work at temperatures up to 250 °C. The sensor and the CMOS readout circuit are processed on SIMOX (Separation by IMplantation of OXygen) substrates. The readout circuit is programmable and allows calibration of linearity, offset and output range. The performance of a 20 bar and a 50 bar sensor is discussed. Even without active temperature compensation the offset temperature coefficient referred to full scale output (FSO) is less than 0.03 %/°C between 25 °C and 150 °C and less than 0.09 %/°C between 150 °C and 250 °C. The linearity error is less than 0.4% FSO.

A CMOS four-quadrant tripler using transistors operated in the subthreshold region is presented. The goal of this circuit is to realize the product of three input signals. This circuit has been implemented in a 0.8 μm single-poly double-metal n-well CMOS process. Experimental results show that for a power supply of ±1.5V, the linear input range of this tripler is within ±100mV with the linearity error less than 2%. The total harmonic distortion is less than 2.5% with input range up to ±100mV. The-3dB bandwidth of this tripler is measured to be about 700 kHz.

A new 3D micro hole measuring system has been developed in this paper. The system is mainly composed of a probe, a rotary stage and a program which can convert data points to a 3D profile. The principle of capacitance is adopted and a device to sense the variation of capacitance when the probe touches the workpiece is designed and implemented. With the aid of rotation stage, positions around the contour are measured. The measured coordinates are calculated by an algorithm proposed in this paper. The developed system is capable of measuring the interior profile of a high aspect ratio micro hole and calculating its roundness. A grade A gauge block is used to verify the developed system. It is found that the repeatability error of the system is within ±0.78 μm. The linearity error can approach 1 μm and the maximum measuring depth is 15 mm. Finally, a micro hole of 1.0 mm in diameter and 10 mm in depth is successfully measured and the 3D profile is constructed accordingly. The roundness of each layer spacing 1 mm apart and the inclination of the axis of the micro hole are calculated as well.