Frequency-temperature Characteristics Research Articles

A thermosensitive quartz resonator with a built-in microheater as a multipurpose sensor

A design of a thermosensitive quartz resonator with a built-in microheater is suggested. The resonator uses a piezoelement of a special crystal cut and has a very high-temperature sensitivity. Because of the linear temperature-frequency characteristic of the resonator, it can be used as a temperature sensor in a wide temperature range—from −20 to 100 °C. The change of the heater’s input power at a constant ambient temperature leads to a corresponding resonator’s frequency change. Because of the linearity of the resonator’s temperature-frequency characteristic the power-frequency dependence is also linear. In such a way the resonator can be utilized as an electrical power meter in the range of 0–400 mW with a sensitivity of about 136 Hz/mW. Using the heater, the resonator can be heated to temperatures higher than the ambient temperature. If the resonator is placed in a path of a flowing liquid, the liquid flow cools the resonator and causes a frequency change, related to the flow rate. The dependence of the resonator’s temperature change on the water flow rate at different input powers has been studied in the range of 0.1–1.2 m/s.

Temperature drift of a magnetic resonance field for a rectangular Bi,Ga substituted YIG film

This paper aims at studying a drift of magnetic resonance field versus temperature for the Bi,Ga substituted YIG film in a rectangular shape. The experimental and theoretical results show that the resonance magnetic field for the rectangular Bi,Ga substituted YIG film having a proper growth induced anisotropy changes parabolically with ambient temperatures and the turnover temperature of the parabolic curve is affected by the aspect ratio of the sample. This size effect can be used as a turnover temperature trimming procedure of the Bi,Ga substituted YIG films for magnetostatic forward volume wave (MSFVW) resonator elements which have reliable resonance frequency-temperature characteristics.

Thickness-shear vibrations in round variable-thickness piezoelectric crystal plates

A computer algorithm proposed for the numerical solution of the problem of natural vibrations of axisymmetric variable-thickness piezoelectric elements can determine the complete spectrum of thickness-shear vibrations of a given class of piezoelectric elements and their displacements distribution. Examples are given of the calculation of the spectrum of piezoelectric elements with the corresponding vibration topograms and the temperature—frequency characteristics and anharmonic vibrations.

Reliable frequency-temperature characteristics of the new quartz-crystal resonators vibrating in thickness-shear modes

This paper describes the turning points of frequency-temperature characteristics for rotated Y-cut quartz-crystal resonators vibrating in b modes in the temperature range 0-300°C. In the high-temperature region, the new experimental results are compared with the theoretical values calculated by use of the idealized thickness-vibration theory.

Low temperature characteristics of electrical parameters in amorphous Si/Si heterojunction bipolar transistors

Measurement of the low temperature characteristics of current gain, H FE, and cut-off frequency, ƒT, in amorphous emitter silicon heterojunction bipolar transistor is reported. The current gain, H FE,, has a positive temperature coefficient and falls with increasing base concentration, N B, at both room temperature and low temperatures. Because of the low-temperature avalanche multiplication effect in the collector-base junction, H FE, increases with increasing applied voltage, V BC, at low temperature. The cut-off frequency, ƒT, has positive temperature coefficient at low current levels and negative temperature coefficient at high current levels. It is concluded finally that the value of H FE of this device at low temperatures is adequate for most applications.

An Analysis of Frequency Temperature Characteristics for New Cut Width-Extensional Mode Quartz Crystal Resonators

An Analysis of Frequency Temperature Characteristics for New Cut Width-Extensional Mode Quartz Crystal Resonators

Saw resonator temperature sensor

Abstract The temperature dependence of a SAW resonator is used to determine temperature. The high linearity of the frequency shift with temperature makes it possible to achieve a high resolution and a high stability with a simple oscillator circuit. Preliminary data for the resonator and the temperature-frequency characteristic are given. The operating principle can also be used to measure the concentration of chemical compounds or elements in liquids or gases, pressure, humidity of gases and many other properties.

Experimental study of a CO 2 laser plasma by coherent anti-Stokes Raman scattering (CARS)

We have studied the temperature characteristics of the radio frequency excited plasma in a CO 2 waveguide laser by the coherent anti-Stokes Raman scattering (CARS). CARS-spectra of the pumping gas N 2 obtained in (broadband) multiplex technique allowed the spectroscopic determination of the population density in the vibrational states of the nitrogen molecule. The measurement of the rotational temperature distribution within the capillary discharge of the tiny cross section of 2.3 × 2.3 mm 2 required the application of a narrowband scanning CARS-technique with higher spectral resolution. The vibrational population experiments reflect the interaction between the intracavity photon flux and the upper level of the CO 2 laser transition, whereas the rotational temperature studies reveal details of both, the energy dissipation by conversion of applied pump energy into laser output and the heat flow into the cooling channels of the capillary discharge device.

An all-optical single-fibre micromachined silicon resonant sensor: Towards a commercial device

A new technique for the actuation and detection of resonant sensor oscillations is presented. Time multiplexing is used to actuate and detect vibrations using a single fibre. The scheme could be extended to permit multiplexing of several sensors onto a single fibre. The pressure and temperature characteristics of the resonance frequency of a device have been measured. The temperature coefficient is found to be negative. The efficiency of actuation is calculated to be roughly 0.02%.

Variational analysis of new shape face shear mode quartz crystal resonator

AbstractThis paper describes a variational analysis, the frequency temperature characteristics and the electrical equivalent circuit constants of a face shear mode quartz crystal resonator with two supporting portions at the ends formed by an etching method. The object of this paper is to propose a new shape face shear mode quartz crystal resonator and to clarify its frequency temperature characteristics and its electrical equivalent circuit constants in the calculation and in the experiments. A vibration analysis is performed according to the following procedure.First, a frequency equation is derived by performing a vibration analysis of a face shear mode resonator being incorporated with a vibrational portion and supporting portions with an energy method. From the obtained frequency equation, a relationship of frequency temperature coefficients vs. a cut angle or a mass ratio is clarified.Second, some of the calculated results are compared with the experimental value. As a result, the calculated and experimental results show good agreement.Finally, various constants of an equivalent circuit for quartz crystal resonators are examined. It is shown that a face shear mode quartz crystal resonator with low series resistance and a high quality factor in the frequency range of 1.5 to 4.2 MHz is obtained, even if supporting portions are added and connected to the vibrational portion.

Frequency Temperature Characteristics and Electrical Characteristics of a New Shape X Cut Longitudinal Quartz Crystal Resonator

Frequency Temperature Characteristics and Electrical Characteristics of a New Shape X Cut Longitudinal Quartz Crystal Resonator

An Analysis of Frequency Temperature Characteristics for a GT-Cut Quartz Crystal Resonator Formed by an Etching Method

An Analysis of Frequency Temperature Characteristics for a GT-Cut Quartz Crystal Resonator Formed by an Etching Method

ディジタル温度補償水晶発振器の過渡周波数温度特性の補償法

ディジタル温度補償水晶発振器の過渡周波数温度特性の補償法

Vibration Analysis of Coupled Flexural Torsional Mode Tuning Fork Type Quartz Crystal Resonator–Part (3)–

This paper describes the frequency temperature characteristics, resonant frequencies, and electrical equivalent circuit constants of a coupled flexural torsional mode tuning fork type quartz crystal resonator which vibrates at the second overtone for flexure and the fundamental vibratinon for torsion. In addition, the object of this paper is, theoretically, to clarify how resonant frequencies and frequency temperature coefficients vary when thickness or a normalized frequency is changed. This resonator changes less than 10 ppm in frequency deviation over a wide temperature range of -20°C to +60°C.

Dependence of Load Capacitance for a Coupling Quartz Crystal Resonator

This paper describes the dependence of load capacitance for a coupling quartz crystal resonator, in particular, a GT cut quartz crystal resonator. The coupling resonator causes a frequency variation by a change of coupling between each vibration. In this paper, it has been theoretically analyzed how the frequency characteristics vary when the coupling intensity is changed, and the results are compared with the experimental values. The coupling intensity between both vibrations is practically performed by the load capacitance CL. This influences frequency temperature characteristics, when discussing ±± ppm in frequency deviation over a wide temperature range of -30°C to +70°C.

Vibration analysis of flexural–torsional mode tuning fork–type resonators

AbstractIt is well known that a flexuraltorsional quartz crystal resonator which couples a torsional mode vibration to a flexural mode vibration, has a cubic curve in frequency temperature characteristics as well as an AT cut quartz crystal resonator. This paper describes the frequency‐temperature characteristics of a tuning fork‐type quartz crystal resonator which couples the torsional mode vibration to the flexural mode vibration and the estimated results of the various constants for the resonator manufactured for trial experiments. First, a secular equation coupled the torsional mode vibration to the flexural mode vibration is calculated. From the secular equation, frequency‐temperature characteristics for the flexural‐torsional mode tuning fork‐type resonator have been analyzed theoretically, specifically concerning a relationship of the resonant frequency, the frequency‐temperature coefficients vs. thickness, a normalized frequency and a cut angle. Next, by manufacturing tuning fork‐type flexural‐torsional quartz crystal resonators, the calculated values are compared with the experimental values, at the same time, the various constants of the resonators manufactured for trial experiments are estimated. As a result, it is confirmed that tuning fork‐type flexural‐torsional quartz crystal resonators with excellent frequency‐temperature characteristics, low‐crystal impedance, and a high quality factor are realized.

Variational analysis of GT‐Cut quartz crystal resonators with the supporting portions at the ends

AbstractIt is well known that a GT cut quartz crystal resonator coupled between two extensional mode vibrations has a cubic curve in frequency‐temperature characteristics as well as an AT cut quartz crystal resonator. This paper studies frequency‐temperature characteristics and electrical characteristics of the GT cut quartz crystal resonator with the supporting portions at both ends of the vibrational portion.First, a secular equation is derived from a vibration analysis of the resonator consisting of the vibrational portion and the supporting portions, by applying the energy method. From this secular equation, a relationship of resonant frequency, frequency temperature coefficients vs. a cut angle, a dimensional ratio and a mass ratio for the GT cut quartz crystal resonator is clarified theoretically. At the same time, from comparison of the calculated values with the experimental values, it is confirmed that they agree very well. Next, electrical characteristics of the quartz crystal resonators manufactured for trial experiments are measured. As a result, it is confirmed that a GT cut quartz crystal resonator with excellent frequency temperature characteristics, low crystal impedance and a high quality factor is realized.

A study of temperature characteristics for rectangular GT‐cut quartz crystal resonators

AbstractThis paper describes the frequency temperature characteristics of a rectangular GT‐cut quartz crystal resonator. First a secular equation is derived from a stress distribution obtained by a thin plate equation and a probe method. From the secular equation, a relationship between resonant frequency, frequency temperature coefficients and cut angle is shown, a dimensional ratio is calculated, and frequency temperature characteristics of the rectangular GT‐cut quartz crystal resonator are clarified. Finally, it is confirmed that the obtained results agree well with the experimental results obtained by Mason and Nakazawa.

A Study of Quartz Temperature Sensors Characterized by Ultralinear Frequency-Temperature Responses

Abstmct-Theoretical and experimental research work on quartz temperalure sensors with doubly rotated cuts characterized by ultralinear frequency-temperature responses has been conducted. According to the experimental results, it is found that the new quartz temperature sensor has a linear frequency-temperature response and a larger frequencpsensitivity lo temperature than the ones of the previously reported. This sensor also has fast thermal time constants for the low temperature transients. NUSUAL climatic phenomena have recently had a most baffling effect on the agriculture, forestry, fishery, and industry all the world over. Therefore, it will be of much importance to make these phenomena well understood and try to present basic ideas that would hopefully lead to world-wide cooperation in coping with the problems. In meteorology, we take an interest in the three-dimensional precision and remote-sensing systems for the global temperature with respect to seawater and the atmosphere. We think that our study will be able to help establish part of those systems, for we have recently discovered a new quartz temperature sensor which exhibits a higher degree of frequency linearity over a wide temperature range compared with the previous types. What is more, it has to be pointed out that the electronic system around the temperature sensor will be much simplified without any device for linearization of frequencytemperature characteristics. The purpose of our research is to help design a sensor characterized by ultralinear frequency-temperature responses. In this paper some features of such sensors will be discussed in detail according to theoretical and experimental results. 11. THEORY Suppose a thin quartz crystal plate whose electrical, mechanical, and optical axes are defined as in the directions of x,, x?, and x3 axes, respectively, as shown in Fig. 1. We denote the direction normal to the main plane by polar

Temperature derivatives of elastic stiffness derived from the frequency-temperature behavior of quartz plates

Linear field equations for small vibrations superposed on thermally-induced deformations by steady and uniform temperature changes are derived from the nonlinear field equations of thermoelasticity in Lagrangian formulation. From the solutions of these equations for the thickness vibrations, the temperature derivatives of elastic stiffness are related analytically to the known or measured properties such as the second- and third-order elastic stiffnesses, thermal expansion coefficients, and temperature coefficients of frequency of quartz plates. Six values of the first temperature derivative C(1)pq and six values of the effective second temperature derivative C̃(2)pq are calculated from the temperature coefficients of frequency measured by Bechmann, Ballato, and Lukaszek for various doubly-rotated quartz plates. The presently calculated values are compared with the first temperature derivatives obtained by Sinha and Tiersten. In the incremental stress-strain-temperature relations, certain expressions involving the elastic stiffnesses, temperature derivatives, and thermal expansion coefficients can be identified as having similar significance as the temperature coefficients of Cpq defined by Bechmann. Values of these expressions are calculated and compared with the existing values. The loci of the zeros of the first and second order temperature coefficients of frequency for thickness shear (B and C) modes and the frequency-temperature characteristics of the LC cut are studied and compared with experimental values.