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Frequency Control Symposium and PDA Exhibition Jointly with the 17th European Frequency and Time Forum, 2003. Proceedings of the 2003 IEEE International

Date 4-8 May 2003

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Displaying Results 1 - 25 of 199
  • Frequency stability of a crystal resonator for biosensors

    Page(s): 981 - 985
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (351 KB) |  | HTML iconHTML  

    This paper describes oscillation frequency stability of a crystal sensor for biosensors used for detection of dioxins, PCB, environmental-stressors, and marker proteins for infections. Present frequency stability is about 0.1 ppm in 9 MHz. Design technology for communication is applied to the crystal unit and oscillator circuit as a sensor. We prepared a crystal unit for filters in an oscillator circuit, and adopted a method that engenders oscillation frequency stability. That method demonstrates performance of 5 ppb at 9 MHz and 14 ppb at 155 MHz. View full abstract»

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  • Broad tuning microwave oscillators utilising multilayer technology and SiGe devices

    Page(s): 417 - 422
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    This paper describes the design of a low phase noise 3.27-5.27 GHz VCO demonstrating phase noise performance varying from -96 to -102 dBc/Hz at 100 kHz offset over the whole band. The VCO incorporates a silicon germanium transistor as the active device. The resonator consists of a printed electrically short transmission line with printed shunt inductors at either end. Two varactor diodes are coupled in parallel to the centre of the resonator. The amplifier is placed on the other side of a 3-layer board and coupled to the resonator using capacitive vias. The oscillator operates at VCE=2 V and IC=30 mA. The design of a broadband (3-6 GHz) negative group delay equaliser capable of cancelling the phase shift in the amplifier is also described although this was not used in the final design due to the high insertion loss. View full abstract»

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  • The study of an interaction of solid particles with various surfaces using TSM sensors

    Page(s): 1001 - 1006
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    The interaction of solid particles with various surfaces has been experiencing growing interest in the area of nanotechnology, colloidal science and biology. In this paper interactions of solid particles with various surfaces using piezoelectric thickness shear mode (TSM) sensors have been studied. A mechanical model has been presented to evaluate the effect of particle loading on the behavior of a TSM sensor. The main sources contributing to the interaction, such as Van der Waals force, gravitational force and electrostatic force, are discussed. Experimental results have shown that the resonant frequency of a TSM sensor depends on the coupling conditions of micro- or nano- particles loaded on the surfaces of a TSM sensor, which is predicted by the theoretical model. The results show that this TSM sensor technique can provide the information of the coupling, such as the binding energy between the particles and the sensor surfaces, and may promote the applications of TSM sensors in characterizing the properties of the loaded particles. View full abstract»

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  • An oscillator for space

    Page(s): 430 - 434
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (368 KB) |  | HTML iconHTML  

    These last years a new 10 MHz quartz crystal oscillator family has been designed in LCEP with the support of the French space agency (CNES). It is intended for space applications especially. In this paper, the description of its general features is followed by two parts. The first one described the methodology which has been developed for designing such an oscillator. This part deals with the modeling of noise as well as the mechanical and thermal structure of the oscillator. The second part summarizes main experimental results. This obviously includes the frequency stability of the oscillator and its behavior when various disturbances occur in its environment. We particularly took care of its sensitivity to external temperature changes at the atmospheric pressure and mainly under vacuum. Exhibited frequency sensitivities to a magnetic field and vibrations are also provided. View full abstract»

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  • Miniaturization of angular rate sensor element using bonded quartz tuning fork

    Page(s): 1007 - 1011
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    We developed an extraordinarily miniaturized quartz tuning fork angular rate sensor element(5.3×0.94×0.24 mm). In order to miniaturize an element without sensitivity degradation, we introduced composite quartz by bonding two monolithic wafers with reversing x axes. Moreover we applied photolithography which achieved fine patterning and excellent productivity. The sensor using the new element accomplished the specifications of angular rate sensor. View full abstract»

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  • Evaluation of oscillator phase noise subject to reliability

    Page(s): 565 - 568
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (307 KB) |  | HTML iconHTML  

    This paper systematically investigates the hot carrier (HC) and soft-breakdown (SBD) induced performance degradations in CMOS voltage-controlled oscillators. After the MOSFET device RF parameter degradations due to HC and SBD effects are experimentally evaluated, the HC and SBD induced performance degradations of a differential 5-stage ring oscillator and a cross-coupled LC oscillator are evaluated for the first time for 0.16 μm technology, focusing on phase noise. Two design techniques are proposed to improve the oscillator performance. The SpectraRF and BERT simulation results verified the effectiveness of the proposed design techniques. View full abstract»

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  • Cavity-Q aging in the gas-cell atomic clock: studies with an atomic-candle signal

    Page(s): 41 - 48
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    Slow variations in cavity Q and microwave power are thought to play a role in the long-term frequency stability of gas-cell atomic clocks. Here, we use an atomic-candle method to study the aging of a TE011 microwave cavity's resonant frequency and quality factor when a glass resonance cell containing Rb87 loads the cavity. Our results suggest that the alkali vapor coats the inside glass surface of the resonance cell with a thin metallic film, and that as this film evolves the quality factor degrades. More generally, the present work demonstrates the efficacy of the atomic-candle method for investigating cavity resonances. In particular, we show that when used in conjunction with more traditional methods, the atomic-candle method has the potential to reveal information on a cavity mode's spatial profile. View full abstract»

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  • Development of Cs atomic fountain frequency standard at CRL

    Page(s): 120 - 122
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    Communications research laboratory (CRL) has been developing a Cesium atomic fountain primary frequency standard. Cs atoms are cooled to below 2 μK by both magneto-optical trap (MOT) and polarization gradient cooling (PGC), and launched vertically by moving molasses method. The launched atoms pass through a microwave cavity twice, on the way upward and downward, and give rise to Ramsey resonance. We succeeded to observe narrower than 1Hz Ramsey signal, and tried to lock the microwave frequency to the atomic resonance. This report presents the current status of the development of CRL atomic fountain. View full abstract»

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  • Characteristics of the unique modes in HBARs

    Page(s): 785 - 793
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (491 KB) |  | HTML iconHTML  

    Simulation results for three kinds of HBARs with different piezo-film and substrate combinations are presented. Based on the distributions of the resonance frequency spacing and the effective coupling factor keff2(m) , which significantly rely on the acoustic impedance ratio of the piezo-film to substrate, a unique mode with maximum keff2(m) can be chosen. For the unique mode of the HBARs, the variations of the Q-value of the series resonance frequency, Qs, the effective coupling factor keff2(m), the motional resistance R1, the capacitance ratio r=C0/C1, the F.O.M.=QsC1/2C0, and Qs·keff2(m), with the thickness of the substrate are calculated. Those data give some guidelines to choose the thickness of the substrate for compromising the parameters of the operating mode. Results showed that it is unnecessary to choose very thick substrate for obtaining high Q. Actually, high Q can be obtained when the thickness ratio to the film reaches about 50 to 150 for the three different kinds of samples. View full abstract»

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  • Impedance matrix and its use for modeling axially polarized piezoceramic cylindrical resonators

    Page(s): 757 - 760
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (262 KB) |  | HTML iconHTML  

    Analytical formulas for the elements of the impedance matrix Z of a cylindrical piezoelectric resonator vibrating in a shear mode are established. The input impedance was calculated employed the established elements of the impedance matrix Z. The analysis presented in this paper can be utilized for the design and construction of the cylindrical piezoelectric sensors, transducers and multi-layer resonators. View full abstract»

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  • IF SAW filters without Love wave's spurious consisting of ZnO film and specific cut angle quartz substrate

    Page(s): 888 - 892
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (359 KB) |  | HTML iconHTML  

    The substrate with large electromechanical coupling factor and excellent temperature coefficient of frequency (TCF) is required to realize surface acoustic wave filters for the first intermediate frequency stage (1st IF). One of the authors (M. Kadota) realized a Rayleigh wave substrate with an excellent TCF and a large electromechanical coupling factor by a combination of a specific quartz substrate (ST-cut 35°X propagation: ST- 35°X) having a positive TCF with a ZnO film having a negative TCF. But, it has been clarified that the SAW filter having of a single electrode (strip) or single-phase unidirectional transducer (SPUDT) on the ZnO/ST-35°X-quartz substrates, often had a large spurious response due to the Love wave which was a higher-order-mode of the Rayleigh wave. The new cutting angle and the propagating direction (26-27°Y-X) on quartz has been developed in order to suppress the spurious response. The IF SAW filters for the wide-band and the narrow-band code division multiple access (W-CDMA: 380 MHz and N-CDMA: 183.6 MHz) have been developed by combining this 26-27°YX quartz with the ZnO film. The IF filters which have a small-size, an excellent TCF, a low insertion loss, a cost advantage in their applications, and no spurious responses due to the Love wave have been realized. Their frequency shift per 1°C from -20°C to 80°C was less than 0.37 ppm/°C, which was better than a Rayleigh SAW on an ST-cut X propagation quartz. View full abstract»

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  • Space clocks for navigation satellites

    Page(s): 172 - 178
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (480 KB) |  | HTML iconHTML  

    The estimation of prediction errors of the Galileo space clocks time is performed via the following steps: a) the determination of errors induced by the geodetic measurement system noise in measuring and predicting the space clock time, based on measurements of GPS clocks produced by the extended GeTT experiment, b) the elaboration of a theoretical model for estimating the clock prediction error due to the system noise, c) the determination by laboratory measurements of the prediction errors of the Galileo clocks intrinsic to the clock characteristics, d) the inclusion of the expected measurement system noise for predicting the Galileo clocks in space. Finally a preliminary study, based on the results of the extended GeTT experiment, gives a rough estimate of the space clock time error bound due to the clock and the software outliers. View full abstract»

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  • Chemical liquid-phase detection using guided SH-SAW: theoretical simulation and experiments

    Page(s): 918 - 926
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (555 KB) |  | HTML iconHTML  

    Results are presented for direct chemical sensing in liquid environments using guided shear horizontal surface acoustic wave (SH-SAW) sensor platforms on 36° rotated Y-cut LiTaO3. Two different sensor geometries are theoretically analyzed. Complex bulk and shear moduli are utilized to represent the viscoelastic properties of the polymers and estimate their influence on the velocity shift and attenuation change, hence on the sensor characteristics. Experimental results are presented and discussed for dual delay line devices with a reference line coated with PMMA and a sensing line coated with a chemically sensitive polymer, which acts as both a guiding layer and a sensing layer. Various chemically sensitive polymers are investigated, and the tested analytes include toluene, ethylbenzene and xylene. Analytes in the low concentration (1 ppm to 60 ppm) range in aqueous solutions are tested. Stability, sensitivity and partial selectivity are investigated by varying the coating thickness and curing temperature for the chemically sensitive layer. Partition coefficients for polymer-aqueous analyte pairs are used to explain the observed trend in sensitivity. Both mass loading and the coating viscoelasticity change influence the sensor response. A low ppb level detection limit is estimated from the present experiment measurement. View full abstract»

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  • Structure-piezoelectric property relationships in α-quartz isotypes: design and characterization of high performance piezoelectric materials

    Page(s): 650 - 653
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (329 KB) |  | HTML iconHTML  

    Structure-property relationships established for α-quartz isotypes indicate that the materials with the most distorted structures exhibit both the highest piezoelectric coupling coefficients and the highest thermal stability. It is found that thermal disorder results in a loss of piezoelectric properties, most noticeably a significant reduction in the Q-factor, particularly in the case of the least distorted materials such as a-quartz itself and this at temperatures well below the α-β phase transition. The most promising materials are predicted to be GeO2 and GaAsO4. These predictions are confirmed by piezoelectric measurements on Y-cut plates of GaAsO4, which yield a piezoelectric coupling constant of about 20%, which is more than twice that of α-quartz. View full abstract»

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  • UHF high-order radial-contour-mode disk resonators

    Page(s): 802 - 809
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (650 KB) |  | HTML iconHTML  

    A micromechanical, laterally vibrating disk resonator, fabricated via a technology combining polysilicon surface-micromachining and metal electroplating to attain sub-micron lateral capacitive gaps, has been demonstrated at frequencies as high as 829 MHz and with Q's as high as 23,000 at 193 MHz. Furthermore, the resonators have been demonstrated operating in the first three radial contour modes, allowing a significant frequency increase without scaling the device, and a 193 MHz resonator has been shown operating at atmospheric pressure with a Q of 8,880-evidence that vacuum packaging is not necessary for many applications. The geometric dimensions necessary to reach a given frequency are larger for this contour-mode than for the flexural-modes used by previous resonators. This, coupled with its unprecedented Q value, makes this disk resonator a choice candidate for use in the IF and RF stages of future miniaturized transceivers. View full abstract»

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  • The RF-powered surface wave sensor oscillator - a successful alternative to passive wireless sensing

    Page(s): 911 - 917
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (585 KB) |  | HTML iconHTML  

    This paper describes a novel passive wireless SAW sensor providing a highly coherent measurand proportional frequency, FM modulated with identification (ID) data and immune to interference with multiple path signals. The sensor comprises a highly stable low-power oscillator, stabilized with the sensing SAW resonator and powered by the rectified RF power of the interrogating signal which is received by a λ/4 whip antenna on the sensor part. A few hundred μW of dc power are enough to power the sensor oscillator and ID modulation circuit and achieve stable operation at 1.0 and 2.49 GHz. Reliable sensor interrogation was achieved over a distance of 0.45 m from a SAW based interrogation unit providing 50 mW of continuous RF power at 915 MHz. The -30 to -35 dBm of returned sensor power was enough to receive the sensor signal over a large distance and through several walls with a simple superheterodyne FM receiver converting the sensor signal to a low measurand proportional intermediate frequency and retrieving the ID data through FM detection. Different sensor implementations including continuous and pulsed power versions and the possibility of transmitting data from several measurands with a single sensor are discussed. View full abstract»

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  • New concept of miniature optically pumped cesium beam frequency standards with a multiwavelength cylindrical cavity

    Page(s): 37 - 40
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (411 KB) |  | HTML iconHTML  

    We developed an optically pumped cesium beam resonator based on a cylindrical cavity meeting the requirements of frequency stability in the range 10-11 τ - 12 /, compactness, lifetime and low cost, for telecom applications. It is named PHACS which means Probatoire d'Horloge Atomique Compacte Simplifiee. We demonstrated that the TE012 cylindrical cavity is the best choice. The interaction length is equal to 90 mm. The configuration of the microwave field in the cavity requires a longitudinal static magnetic field, created by a solenoid which surrounds the cavity and the optical regions dedicated to the state preparation and to the detection of the atoms. Constitutive elements of the resonator are designed with a cylindrical symmetry. The resonator is operated with only one optical frequency tuned to a transition in the D1 line of the cesium atom. The main drawback of the cavity is the distributed phase along the atomic path. To control this problem, we implemented an original magnetic coupling which enables us to control any asymmetry between the two cavity lobes. The main features of the resonator PHACS are: a volume of 1.8 dm3, a line-width of 2.2 kHz and a signal to noise ratio of 10,000 in a 1Hz bandwidth. The short term frequency stability is 1.2 10-11 τ - 12 / from 1s to 10,000s. The relative frequency offset is 2.5 10-12 from TAI. View full abstract»

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  • GPS time interval and state measurement for PARCS

    Page(s): 185 - 190
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (475 KB) |  | HTML iconHTML  

    A science-quality space GPS receiver is being studied for the primary atomic reference clock in space (PARCS) mission. The PARCS flight experiment is an International space station (ISS) payload that will conduct investigations into the laser cooling of atoms, time interval measurement, and fundamental physics. The receiver will make GPS carrier phase observations, to transfer the frequency measurements made by other PARCS subsystems to the ground and to determine the experiment's precise position and velocity. The receiver is based on the Jet Propulsion Laboratory's BlackJack radiometric instrument. This is a dual frequency, codeless design that is a veteran of multiple spaceflights. The major challenges for its use on PARCS derive from the ISS environment, for example, the antenna field of view, multipath sources, and potential electromagnetic interference. Simulations indicate that the restricted field of view will be the main limitation, and that the receiver antenna should be tilted away from the ISS structure by ∼30° for better results. The use of GPS ground networks and data analysis techniques to provide a total measurement system adequate to meet PARCS' requirements will need to be examined further. View full abstract»

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  • Progress in the building of sapphire-helium clock at LPMO

    Page(s): 355 - 359
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (401 KB) |  | HTML iconHTML  

    We report a new high-Q sapphire whispering gallery mode resonator to achieve ultra high frequency stability. We propose to excite a sapphire resonator in an opened cavity to suppress number of low order spurious modes. Providing the azimuthal order of the chosen whispering gallery mode is high enough, Q-factors better than 2.108 have been observed which turns out to be sufficient to reach a high frequency stability. A realization of a 12 GHz WGH sapphire helium oscillator shows a relative frequency instability of 2·10-14 in terms of standard deviation. View full abstract»

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  • Temperature-compensated cuts for vibrating beam resonators of gallium orthophosphate GaPO4

    Page(s): 663 - 667
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (318 KB) |  | HTML iconHTML  

    A theoretical investigation of rectangular cross-section GaPO4 vibrating beam resonators is proposed. Flexural modes are the basic vibrating mode of tuning forks used in quartz wrist watches, and can also be used as sensors. Very little work, if any, has been done for vibrating beam resonators in GaPO4. The goal is then to investigate the possibility of temperature-compensated cuts for all three kinds of vibrations in GaPO4: extensional, flexural, and torsional modes by analytical methods. Modeling temperature effects is achieved by the approximate but classical method of varying effective elastic constants, beam dimensions and crystal mass density versus temperature. Temperature-compensated cuts are found in GaPO4 for length extensional modes and flexural modes. For vibrating beams, some of temperature-compensated cuts of GaPO4 exhibit inversion points at high temperatures. View full abstract»

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  • The dependence of phonon and paramagnetic resonances on the fine structure constant in sapphire and the possibility of a test of time dependence

    Page(s): 211 - 16a
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    A new experiment to test for the time independence of the fine structure constant, α, is proposed. The experiment is based on a similar proposal at optical frequencies. We propose to utilize orthogonally polarized transverse electric and transverse magnetic whispering gallery modes in a single sapphire resonator tuned to similar frequencies. When configured as a dual mode sapphire clock, we show that the anisotropy of sapphire makes it possible to undertake a sensitive measurement from the beat frequency between the two modes. At infrared frequencies this is possible due to the different effect of the lowest phonon frequency on the two orthogonally polarized modes. At microwave frequencies we show that the phonon effect is too small. We show that the electron spin resonance of paramagnetic impurities (such as Cr3+) in the lattice effects only one polarization with an α6 dependence. This enables an enhancement of the sensitivity to temporal changes in α at microwave frequencies. In both cases degradation of cavity Q is experienced due to Kramers Kronig relations. The effect on both cases is assessed. View full abstract»

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  • Algorithmic optimization of spectral and temperature characteristic of MTCXO

    Page(s): 450 - 457
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    The creation of a digital thermocompensation system is possible now on a basis of single chip of typical microcontroller. In paper the problems of assuring of clean spectrum characteristics of DTCXO output signal on the basis microcontroller at usage of the cheapest DAC solution-PWM are considered. The variants of control voltage shaping accuracy increasing are considered at the expense of second and higher orders PWM realization. The optimization of choice algorithm order is carried out. Besides, the variants of ADC accuracy increasing are described at the expense of special algorithms of statistical handling. View full abstract»

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  • A micro-acoustic wave sensor for engine oil quality monitoring

    Page(s): 971 - 977
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (460 KB) |  | HTML iconHTML  

    A micro-acoustic wave sensor based on the thickness shear mode (TSM) quartz resonator has been investigated for engine oil quality monitoring through the viscosity measurement. Effects of the fluid mechanical and electrical properties on the TSM resonator with both sides in contact with the fluid have been studied and compared to the 1-sided device. Sensor prototypes based on both the 1- and 2-sided TSM resonators have been developed and tested in various fresh and used engine oils. View full abstract»

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  • Investigations on the langasite resonators by X-ray topography

    Page(s): 637 - 641
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (417 KB) |  | HTML iconHTML  

    In this paper the results of electrical measurements of the mass-loading influence on Y-cut langasite resonator parameters are compared with those obtained by X-ray topography analysis of the same resonators. Based on the Ballato's transmission-line analogs of the trapped-energy resonators vibrating in thickness-shear mode, the mass-loading effect on resonator characteristics was studied. The effective mass-loading, motional inductance and quality factor of langasite resonators were computed. Sawyer plan-parallel polished Y-cut langasite resonators with 14 mm diameter, 5 MHz resonant frequency, Au electrodes of 7 mm diameters and various thickness were used in experiments. X-ray topography measurements were performed by conventional transmission Laue setting using the white beam synchrotron radiation on fundamental, third and fifth overtones. The results are in agreement with those obtained by electrical measurements. The comparison of X-ray diffraction topography images previously performed on AT-cut quartz resonators with X-ray topographs on langasite resonators pointed out that the Y-cut langasite resonators are less influenced by the mass-loading than the AT-cut quartz resonators. View full abstract»

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  • A mass/heat flow sensor combining shear mode resonators with thermoelectrics: principles and applications

    Page(s): 1062 - 1065
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (312 KB) |  | HTML iconHTML  

    We describe a new way to monitor chemical and biological processes occurring in thin films interacting with gases and liquids, using a mass/heat flow sensor. The thin films may be metals, polymers, paints or coatings, chemical samples, proteins, catalysts, or monolayers. Changes in mass and in coating stiffness as well as heat generated by chemical or biological process on or in the film are measured with high sensitivity. We call the technique "quartz/crystal microbalance/heat conduction calorimetry" (QCM/HCC). View full abstract»

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