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Sensors Journal, IEEE

Issue 11 • Date Nov. 2013

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Displaying Results 1 - 25 of 67
  • [Front cover]

    Page(s): C1
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  • IEEE Sensors Journal publication information

    Page(s): C2
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  • Table of contents

    Page(s): 4105 - B4108
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  • Table of contents

    Page(s): 4109 - B4112
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  • Fiber Optic Bending Sensor for Water Level Monitoring: Development and Field Test: A Review

    Page(s): 4113 - 4120
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1856 KB) |  | HTML iconHTML  

    In this paper, we describe a low cost optical sensor of water level based on fiber bending effect associated to the use of an elastomeric membrane. The sensor proposed has a particular design to be simple, reliable, and low cost. It is suitable to be used in tubes of embankment dams, tanks, and reservoirs. The sensor uses a standard single mode fiber and can measure the water levels up to 10 m or more, choosing the appropriate membrane. This paper describes the development of the sensor, a theoretical modeling, and the results of laboratory and field tests. Seven sensors were installed in an embankment dam where they have been used in a real time monitoring system based in optical time domain reflectometry. View full abstract»

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  • Directions Toward Effective Utilization of Tactile Skin: A Review

    Page(s): 4121 - 4138
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2249 KB) |  | HTML iconHTML  

    A wide variety of tactile (touch) sensors exist today for robotics and related applications. They make use of various transduction methods, smart materials and engineered structures, complex electronics, and sophisticated data processing. While highly useful in themselves, effective utilization of tactile sensors in robotics applications has been slow to come and largely remains elusive today. This paper surveys the state of the art and the research issues in this area, with the emphasis on effective utilization of tactile sensors in robotic systems. One specific with the use of tactile sensing in robotics is that the sensors have to be spread along the robot body, the way the human skin is-thus dictating varied 3-D spatio-temporal requirements, decentralized and distributed control, and handling of multiple simultaneous tactile contacts. Satisfying these requirements pose challenges to making tactile sensor modality a reality. Overcoming these challenges requires dealing with issues such as sensors placement, electronic/mechanical hardware, methods to access and acquire signals, automatic calibration techniques, and algorithms to process and interpret sensing data in real time. We survey this field from a system perspective, recognizing the fact that the system performance tends to depend on how its various components are put together. It is hoped that the survey will be of use to practitioners designing tactile sensing hardware (whole-body or large-patch sensor coverage), and to researchers working on cognitive robotics involving tactile sensing. View full abstract»

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  • Long Period Fiber Grating Humidity Sensor With Gelatin/Cobalt Chloride Coating

    Page(s): 4139 - 4140
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (323 KB) |  | HTML iconHTML  

    A long period fiber grating (LPFG) coated with a combination of cobalt chloride and gelatin is proposed and demonstrated for the monitoring of relative humidity (RH) levels. The thin overlay of the combination and its spectral properties with respect to different ambient humidity levels are observed. Field emission scanning electron microscope and atomic force microscope have provided detailed evidence of attachment of the amalgamation on LPFG surface using adapted coating methodology. The results show a significant shift in the resonance wavelength of the coated LPFG when the RH is varied from 35% to 90%, with a sensitivity of 0.18 nm/% RH and accuracy of 98.55%. View full abstract»

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  • Frequency Response Improvement for Inertial Magnetoelectric Velocity Sensor Using Frequency-Selected Compensation Network

    Page(s): 4141 - 4146
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2102 KB) |  | HTML iconHTML  

    The inertial magnetoelectric velocity sensor is widely used in the fields of vibration control and measurement. The frequency response in the low frequency range is, however, limited by high frequency resonance because of the characteristic of second order high pass filter of the structure. A frequency-selected network for amplitude-frequency characteristic compensation to improve the performance of the frequency response is presented. The frequency-selected network, which is composed of amplifiers, resistors, and capacitances, is connected to the output port of the sensor in cascade without any modification of the sensor's structure. After compensation, the frequency band of the sensor is flattened and frequency response still has the characteristic of second order high pass filter, whereas the resonant frequency decreases from ~ 10 to 0.93 Hz. Meanwhile, it keeps the transducer in small size and light weight. The experimental results have shown that the sensor after been compensated has good performance in the low frequency range. View full abstract»

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  • A Robust Polynomial Filtering Framework for Mammographic Image Enhancement From Biomedical Sensors

    Page(s): 4147 - 4156
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (998 KB) |  | HTML iconHTML  

    This paper presents a non-linear framework employing a robust polynomial filter for accomplishing enhancement of mammographic abnormalities outcoming from biomedical instrumentation, i.e., X-rays instrumentation. The approach proposed in this paper uses a linear combination of Type-0 and Type-II polynomial filters as a generalized filtering solution to achieve enhancement of mammographic masses and calcifications irrespective of the nature of background tissues. A Type-0 filter provides contrast enhancement, suppressing the ill-effects of background noise. On the other hand, Type-II filter performs edge enhancement leading to preservation of finer details. Contrast improvement index is used as a performance measure to quantify the degree of improvement in contrast of the region-of interest. In addition, estimation of signal-to-noise ratio (in terms of PSNR and ASNR) is carried out to account for the suppression in background noise levels and over-enhancements of the processed mammograms. These measures are used as a mechanism to optimally select the filter parameters and also serve as a quantifying platform to compare the performance of the proposed filter with other non-linear enhancement techniques to be used for diverse biomedical image sensors. View full abstract»

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  • A Wide Range Conductometric pH Sensor Made With Titanium Dioxide/Multiwall Carbon Nanotube/Cellulose Hybrid Nanocomposite

    Page(s): 4157 - 4162
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    We report the fabrication and characterization of a pH sensor made with titanium dioxide (TiO2)/multiwall carbon nanotube (MWCNT)/cellulose hybrid nanocomposite. The TiO2-coated MWCNTs are synthesized by hydrothermal process. The X-ray diffraction and Raman spectra observations show that high anatase crystalline TiO2 nanoparticles are well formed on the surface of MWCNTs. After blending the TiO2/MWCNTs with cellulose solution, the TiO/MWCNT/cellulose hybrid nanocomposite is made and used for the pH sensor. This nanocomposite pH sensor exhibits two linear regions in its conductance between pH 1 and 12. Large surface area of the hybrid nanocomposite increases adsorption sites of ions so as to increase the pH sensitivity as well as sensing range. The long-term stability test and reusable test demonstrate that this hybrid nanocomposite pH sensor is useful for many practical applications. The pH sensing mechanism of this hybrid nanocomposite pH sensor is also discussed in this paper. View full abstract»

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  • On the Use of Modified Cramér-Rao Bound in Sensor Deployment

    Page(s): 4163 - 4171
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    This paper proposes the application of the modified Cramér-Rao bound (MCRB) in a sensor network to perform a prior analysis of the operation in the localization task. This analysis allows knowledge of the behavior of the system without a complete deployment. It also provides essential information to select properly fundamental parameters. To do so, a complete formulation of the modified information matrix and MCRB is developed for the most common measurement models, such as received signal strength, time of arrival, and angle of arrival. In addition, this formulation is extended for heterogeneous models that combine different measurement models. Simulation results demonstrate the utility of the proposed analysis and point out the similarity between MCRB and Cramér-Rao bound. View full abstract»

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  • Wireless Energy and Data Transfer for In-Vivo Epileptic Focus Localization

    Page(s): 4172 - 4179
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (824 KB) |  | HTML iconHTML  

    This paper presents a wireless energy transfer and a wireless data communication link for neural signal monitoring-more specifically, fast ripple detection for epilepsy patients. Wireless data are transferred on the same channel as the wireless energy transfer link by shifting resonance frequency of the implanted part. The remote powering link consists of a four-coil resonant inductive link structure and a power management unit on the implant side. Modulated information on the implant is demodulated using an envelope detector type amplitude shift keying demodulator in the external unit. Power transfer efficiency in air without data communication is measured as 36% for 10 mW output power at 8.4 MHz excitation frequency, while the external and the implanted coils are separated by 10 mm. Under the same experimental conditions, 1 Mbit/s data communication is achieved while maintaining a power transfer efficiency of 33%. Moreover, in-vitro tests employing mock cerebrospinal fluid are performed and 1 Mbit/s data communication is performed with an efficiency of 33% while all other parameters are preserved. Finally, hermetical sealing capability of the packaging that is composed of epoxy and Parylene-C is successfully tested for one month to evaluate the implant's short-term performance. View full abstract»

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  • Fabrication and Investigation of Arrayed Glucose Biosensor Based on Microfluidic Framework

    Page(s): 4180 - 4187
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    In this paper, an arrayed glucose biosensor is integrated to the poly-dimethylsiloxane microchannel as the microfluidic device for measuring the characteristics of the arrayed glucose biosensor at dynamical conditions. The radio frequency sputtering system and screen printed technology are used to fabricate the arrayed glucose biosensor. Furthermore, the computer numerical control technique is used to fabricate the microchannel mold. The polypyrrole differential reference electrode has good stable characteristics and provides a stable potential for the arrayed pH sensor. At static conditions, the average sensitivity and linearity of the arrayed pH sensor are 57.85 mV/pH and 0.977, respectively. And at dynamical conditions with 20 mL/min flow rate, the average sensitivity and linearity of the arrayed pH sensor are 66.73 mV/pH and 0.993, respectively. The arrayed pH sensor is dropped glucose sensing membranes as an arrayed glucose biosensor. The arrayed glucose biosensor is measured in different glucose concentrations at static conditions, and the average sensitivity and linearity of the arrayed glucose biosensor are 11.84 mV(100 mg/dl)-1 and 0.995, respectively. At dynamical conditions with 25 mL/min flow rate, the average sensitivity and linearity of the arrayed glucose biosensor are 30.41 mV(100 mg/dl)-1 and 0.975, respectively. View full abstract»

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  • Optimal Truncated Ordered Sequential Cooperative Spectrum Sensing in Cognitive Radio

    Page(s): 4188 - 4195
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (836 KB) |  | HTML iconHTML  

    The cost for increasing the accuracy of cooperative spectrum sensing in cognitive radio requires a long time for collecting sensing data. Sequential fusion, in which the sensing data reports are sequentially collected, combined, and tested with two thresholds for deciding to wait for the next data report or concluding the presence or absence of the primary signal, is considered to reduce the collecting time. A further reduction in the average sequential report number (ASN) can be achieved by arranging the reports in descending order of data quality where the better sensing data is reported earlier. In this paper, the ASN and the error probability of the ordered sequential fusion are analytically calculated based on the direct method. The results are then adopted to design an optimal method for obtaining the optimal sequential thresholds and truncated point. The optimal truncated point enables one to minimize the ASN by discarding the sensing data with low quality, while the optimal sequential thresholds ensure the maintaining of the sensing performance of sequential fusion be the same level to that of the conventional parallel fusion. View full abstract»

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  • On the Design of Video-Bandwidth Electric Field Sensing Systems Using Dielectric {\rm LiNbO}_{3} Electro-Optic Sensors and Optical Delays as Signal Carriers

    Page(s): 4196 - 4203
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (806 KB) |  | HTML iconHTML  

    As the measurement of wide-band (multi-megahertz) electric fields is often of practical interest in industrial and commercial environments, in this paper, a methodology of design and implementation of a wide-band electric field sensing scheme, using optical delays as information carriers is described. The scheme is based on a lithium niobate (LiNbO3) birefringent optical waveguide that performs simultaneously as an optical retarder and as a dielectric (electrode-less) sensor. In this scheme, the LiNbO3 sensor introduces an optical delay and simultaneously senses an on-air electric field and imprints it around an optical delay. At the receiver, the sensed electric field is detected when the sensor and demodulator are optically matched, i.e., when both introduce identical optical delays. An important aspect, when sensing electric fields using LiNbO3 dielectric sensors, is that the optically sensed field is weaker than the external field by a factor given by the ratio of the permittivity of the surrounding dielectric media over the LiNbO3 permittivity (boundary condition for normal electric fields). When the surrounding media is air, the optically sensed electric field is 35 times weaker than the external field, as described in this paper. Another practical issue is that a birefringent optical waveguide is highly sensitive to optical polarization variations. Such a sensitivity implies that the output dc component of the received light changes with time (dc-drift). The dc-drift performance of the proposed electric field sensing scheme is measured and reported in this paper. The dc-drift can be minimized using polarization-insensitive LiNbO3 unbalanced Mach-Zehnder interferometers. View full abstract»

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  • Electromagnetic Biosensing of Respiratory Rate

    Page(s): 4204 - 4211
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1171 KB) |  | HTML iconHTML  

    Continuous monitoring of respiratory rate is crucial in forecasting health crises and other major physiological instabilities. Current respiratory monitoring methods limit the mobility of the patient or require constant battery replacement. Wireless, wearable technology can collect continuous physiological data without immobilizing or inconveniencing patients, and human energy harvesting can be used to power these wearable sensors. In this paper, we explore this zero-net energy biosensor concept through simultaneous sensing and harvesting of respiratory effort. An off-the-shelf dc brushed motor is modified into a chest belt, and tested on a mechanical chest simulator as well as on 20 human subjects, using a spirometer as a reference. The electromagnetic biosensor is used to successfully harvest 7-70 μW from human subjects. On the mechanical chest, respiratory rate is detected with a mean absolute error of 0.00027 breaths/min with a standard deviation of 0.00019 breaths/min. For human subjects, respiratory rate is detected with a mean difference of 0.36 breaths/min with a standard deviation of 2.83 breaths/min (sitting), 0.23 breaths/min with a standard deviation of 2.64 breaths/min (standing), and 0.48 breaths/min with a standard deviation of 3.06 breaths/min (walking). View full abstract»

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  • Layer-by-Layer Structured AuNP Sensors for Terpene Vapor Detection

    Page(s): 4212 - 4219
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1884 KB) |  | HTML iconHTML  

    A localized surface plasmon resonance (LSPR) sensor based on self-assembled Au nanoparticle (AuNP) multilayers is developed for the detection of volatile terpenes that are considered to be biomarker gases during the growth process of plants. The sensor is fabricated by an alternate deposition of a bifunctional dithiol cross-linker and AuNPs. UV-vis spectra, atomic force microscopy images, and scanning electron microscope images of AuNP multilayers are investigated to analyze their LSPR spectra and refractive index sensitivity to terpene vapors. The results show that the optical properties of NP multilayers are jointly decided by the molecular length and chemical nature of dithiol linkers. The electric field coupling of AuNPs occurred in inter- and intra-layers determined by the refractive index sensitivity (RIS) of the sensor. The normalized RIS of the AuNP multilayer is about three times higher than that of the monolayer. The responses of AuNP multilayer sensors to changes in terpene vapor concentration are rapid, reversible, and reproducible. View full abstract»

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  • Single-Mode-Multimode Fiber Structure Based Sensor for Simultaneous Measurement of Refractive Index and Temperature

    Page(s): 4220 - 4223
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (892 KB) |  | HTML iconHTML  

    A fiber sensor for simultaneous measurement of refractive index (RI) and temperature in solutions based on multimode interference is presented. The intensity and the wavelength of the interference minimum will vary with the RI and the temperature of the solution, respectively. The sensitivity of the RI and the temperature are 94.58 dB/RI and 0.0085 nm/°C, respectively. Its ease of fabrication and low-cost offer the attractive applications in chemical and biological sensing. View full abstract»

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  • Portable Passive Millimeter-Wave Sensor for Detecting Concealed Weapons and Explosives Hidden on a Human Body

    Page(s): 4224 - 4228
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (774 KB) |  | HTML iconHTML  

    This paper describes a portable passive millimeter-wave sensor designed for remote detection of both metallic and non-metallic objects hidden on a human body under cloth. The sensor is based on a directly detection and analyses of the energy emitted by a human body. The algorithm of detection estimates unimodality features of traces recorded in the process of a manual scan. The sensor demonstrates a detection probability in the laboratory environment close to 100% at a distance of up to 3 m for the tested samples of explosives and metal objects hidden under cloth. View full abstract»

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  • Electronic Nose System Based on Quartz Crystal Microbalance Sensor for Blood Glucose and HbA1c Levels From Exhaled Breath Odor

    Page(s): 4229 - 4235
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (575 KB) |  | HTML iconHTML  

    It is known that the rate of acetone in human breath changes in diabetics. The organs in the human body produce different gases. During cleaning of the blood, which is transmitted to the lungs and into the blood gases, the breath passes through the alveoli. Human breath acetone concentration is very low (0.1-10 ppm). This paper aims to determine human blood glucose and HbA1c levels from exhaled breath as a non-invasive method with the help of an electronic nose system based on quartz crystal microbalance (QCM) sensors. The amount of acetone vapor, which is the marker of blood glucose, is 0.1-10 ppm in human expiration. Data of the QCM sensor used in the electronic nose are compared against glucose and HbA1c parameters in blood by using a radial basis function neural network (RBFNN). When breath data are implemented to the RBFNN, the average accuracy rate is 83.03% and 74.76% for HbA1c parameter predictions and glucose parameter predictions, respectively. View full abstract»

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  • Geometrical Analysis of Localization Error in Stereo Vision Systems

    Page(s): 4236 - 4246
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (723 KB) |  | HTML iconHTML  

    Determining an object location in a specific region is an important task in many machine vision applications. Different parameters affect the accuracy of the localization process. The quantization process in charge-coupled device of a camera is one of the sources of error that causes estimation rather than identifying the exact position of the observed object. A cluster of points, in the field of view of a camera are mapped into a pixel. These points form an uncertainty region. In this paper, we present a geometrical model to analyze the volume of this uncertainty region as a criterion for object localization error. The proposed approach models the field of view of each pixel as an oblique cone. The uncertainty region is formed via the intersection of two cones, each emanating from one of the two cameras. Because of the complexity in modeling of two oblique cones' intersection, we propose three methods to simplify the problem. In the first two methods, only four lines are used. Each line goes through the camera's lens, modeled as a pinhole, and then passes one of the four vertices of a square that is fitted around the circular pixel. The first proposed method projects all points of these four lines into an image plane. In the second method, the line-cone intersection is used instead of intersection of two cones. Therefore, by applying line-cone intersection, the boundary points of the intersection of the two cones are determined. In the third approach, the extremum points of the intersection of two cones are determined by the Lagrangain method. The validity of our methods is verified through extensive simulations. In addition, we analyze effects of parameters, such as the baseline length, focal length, and pixel size, on the amount of the estimation error. View full abstract»

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  • Spectrum Sensing in Opportunity-Heterogeneous Cognitive Sensor Networks: How to Cooperate?

    Page(s): 4247 - 4255
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2688 KB) |  | HTML iconHTML  

    Cognitive sensor network (CSN) is a promising paradigm to address the spectrum scarcity problem in traditional wireless sensor networks. Reliable spectrum sensing is essential to enable the normal operation of a CSN. Existing researches showed that by exploiting spatial diversity, cooperative sensing can greatly improve the detection performance over non-cooperative sensing in opportunity-homogeneous environment. At a given time, cognitive sensors at different locations, however, may experience heterogeneous spectrum opportunities making the cooperation among cognitive sensors intractable. In this paper, we show the limitations and drawbacks of merely using temporal-domain detection performance metrics and introduce novel spatio-temporal detection performance metrics to guide the design of joint spatio-temporal spectrum sensing. An efficient one-bit hard decision based three-phase (i.e., a global cooperation phase, a local cooperation phase, and a joint decision phase) spatio-temporal sensing algorithm is proposed and numerical results demonstrates the effectiveness of the proposed algorithm. View full abstract»

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  • Aerosol-Printed Strain Sensor Using PEDOT:PSS

    Page(s): 4256 - 4263
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1701 KB) |  | HTML iconHTML  

    Recently, printed electronics have received growing attention as a method to produce low-cost large-area electronics on flexible substrates. This technology relies on printing techniques to deposit electrically functional materials onto flexible substrates to fabricate circuits with various electronic components such as resistors, capacitors, and transistors. In this paper, we apply the printed electronics technology to the development of strain sensors for measuring dynamic strain of a structure. To print sensors, we develop an aerosol printing system capable of atomizing a material solution into microscopic particles and depositing the particles on a target surface. Using this system, a water-based conductive polymer, PEDOT:PSS solution is deposited on a plastic beam. Then, piezoresistive sensing capabilities of the printed strain sensor are studied for low frequency cyclic loadings. Finally, the performance of the printed sensor is compared with a conventional thin-foil strain gauge for measuring dynamic strain of a beam under free vibration. The results show that this type of printed strain sensor can be used to accurately measure structural vibrations. View full abstract»

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  • A Novel Closed-Loop Readout Topology for Monolithically Integrated Surface Acoustic Wave Sensors

    Page(s): 4264 - 4270
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1727 KB) |  | HTML iconHTML  

    A new frequency to voltage closed-loop integrated sensor circuit suitable for the read-out module of a monolithically integrated SAW sensor on Si is proposed. This closed-loop system consists of a voltage controlled oscillator, a peak detecting comparator, a finite state machine, and the monolithically integrated SAW sensor device. The output of the system is forced to oscillate within a narrow voltage range that correlates with the SAW pass-band response. The period of oscillation is of the order of the SAW phase delay. The output voltage range varies with changes in SAW center frequency, thus tracking mass sensing events in real time. The analysis and simulation of the system are presented for two SAW devices operating at 374 and 140 MHz, respectively. Experimental results for a test chip fabricated with AMIC5N 0.5 μm process are presented for comparison with simulation data of the 140 MHz design. Because of this frequency to voltage conversion, this approach is uniquely suitable for full monolithic integration of autonomous sensor systems and tags. View full abstract»

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  • Spatial Resolution Improvement of Distributed Raman Temperature Measurement System

    Page(s): 4271 - 4278
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (514 KB) |  | HTML iconHTML  

    Ensuring the synchronization of backscattered Raman light and improving the sampling rate are of great importance to improve the spatial resolution of a distributed Raman temperature measurement system. To keep the synchronization of the Anti-Stokes and Stokes light and improve the sampling rate, four effective methods are proposed in this paper. First, the asynchrony caused by the difference in the hardware is eliminated by attaching a fiber to the pigtail of APD, which detects the earlier arriving signal. Next, the data acquisition card chooses different sampling rates for the Anti-Stokes and Stokes light according to the velocity of propagation. Then, a new algorithm is adopted to decrease the difference in the fiber position between the Anti-Stokes and Stokes signals. Finally, the optical switch with different length of pigtails is applied to improve the sampling rate without upgrading the hardware of data acquisition card. By theoretical analysis and experimental simulation, the proposed measures in this paper can improve the spatial resolution effectively. View full abstract»

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The IEEE Sensors Journal is a peer-reviewed, monthly online/print  journal devoted to sensors and sensing phenomena

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Editor-in-Chief
Krikor Ozanyan
University of Manchester
Manchester, M13 9PL, U.K.