Cut Quartz Crystal Resonator Research Articles

Noncontact excitation of quartz crystal resonator chips

The use of an acoustic wave device as a chemical sensing element is often limited by contact with wires and supports and by the need to control its fluidic environment. This letter describes the validation of a versatile noncontact configuration that makes use of a spiral coil antenna to electromagnetically excite miniature piezoelectric chips. Experimental evidence is provided to demonstrate that an AT cut quartz crystal resonator can be cleaved into chips that can be excited electromagnetically via coupling to the electric Y axis of the crystal. An unpredicted result was the superior coherence of chips at frequencies determined by their local thickness.

Experimental study on the characteristic of the NS-GT cut quartz crystal resonator oscillating in the sub-resonant frequency

We previously reported that the dynamic photo-elastic method was a very effective measuring technique for the stress distribution of vibrating quartz crystal resonators. The existence of a twisted asymmetrical vibration mode has been verified experimentally when the NS-GT cut quartz crystal resonator was vibrating in the main resonant frequency (MRF). A MRF and a sub-resonant frequency (SRF) of the NS-GT cut quartz resonator were defined as follows. If a mechanical standing wave was in the x' or y' direction of the resonator, the former was MRF vibration and the latter was SRF vibration, respectively. In this paper, stress distributions of two samples of the NS-GT cut quartz crystal resonator, one of which had a thickness of 80 mum and the other 150 mum, were measured by the dynamic photo-elastic method when the resonators were vibrating in each SRF. Thereafter, vibration modes of those resonators were estimated by the experimental data of stress distributions. We find that the vibration mode of the 80-mum resonator had a simple mechanical standing wave on the y' direction and the vibration mode of the 150-mum resonator was combined with a shearing mode in the SRF vibration. From the experiment, we decided that vibration modes of the NS-GT cut quartz crystal resonator were composed of the longitudinal stress T(3)' belonging to the z' direction of the plate and of the shearing stress T(5)' when the plate thickness was thickened and the resonator was oscillating in the SRF.

Application of the photo-elastic method to measurement of dynamic stress distribution for NS-GT cut quartz crystal resonators

NS-GT cut quartz crystal resonators are widely used as a frequency standard element in consumer products and communication equipment. The vibration mode of the resonators was analyzed by the finite element method (FEM) because they have a complicated shape. As a result, an asymmetrical vibration mode at the main resonant frequency has been obtained by the FEM simulation. But, it is necessary to confirm the asymmetrical vibration mode experimentally because it is just a simulation. In this paper, stress distributions of the NS-GT cut quartz crystal resonators are measured experimentally by using a dynamic photo-elastic method when the resonators are vibrating in the resonant frequency; thereafter, vibration modes of the NS-GT cut resonators are estimated with the experimental data of the stress distributions. This experiment for the NS-GT cut quartz crystal resonators exposes the existence of a twisted asymmetrical vibration mode at the main resonant frequency, with the magnitude of the twisted vibration in proportion to thickness of the resonators.

Reviews Of Acoustical Patents

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A Method of Adjusting Resonant Frequency and Frequency Temperature Coefficients for NS-GT Cut Quartz Crystal Resonators

A Method of Adjusting Resonant Frequency and Frequency Temperature Coefficients for NS-GT Cut Quartz Crystal Resonators

Precise Determination of the Optimum Supporting Position of a Stress Compensated (SC) Cut Quartz Crystal Resonator Using a Semiconductor Pulsed-Laser System

This paper describes a precise method of determining the supporting position of a stress compensated (SC) cut crystal wafer using a semiconductor pulsed laser. Because the supporting position greatly influences the frequency stability against acceleration and/or external stress, an accurate determination method is required. The experimental results for circular SC-cut quartz resonators with various supporting positions demonstrate the validity of this technique.

A Method of Adjusting Frequency Temperature Coefficients and Resonant Frequency for NS-GT Cut Quartz Crystal Resonators

This paper describes a method of adjusting the frequency-temperature coefficients and resonant frequency of NS-GT cut quartz crystal resonators. It is well known that NS-GT cut resonators show good frequency-temperature behavior because the first-, second- and third-order temperature coefficients α+, β+, γ+ for principal vibration can be approximately zero. However, a distribution of frequency-temperature behavior takes place in production. In order to obtain resonators with better and stable frequency-temperature behavior within +/-2.5 ppm over a temperature range of -30 to +85° C in production, an absolute value of α+ must be less than 5×10-8/° C. The adjustment method described makes it possible to control α+ easily. The NS-GT cut resonators' frequency-temperature characteristics were found to be mostly within +/-1.0 ppm in the above-mentioned temperature range.

Behavior of Sub-Vibration for NS-GT Cut Quartz Crystal Resonators.

Behavior of Sub-Vibration for NS-GT Cut Quartz Crystal Resonators.

正誤

正誤

新形状GTカット水晶振動子の支持部寸法と板厚による諸特性への影響

新形状GTカット水晶振動子の支持部寸法と板厚による諸特性への影響

Oscillation Frequency Characteristics in a CMOS Oscillator Circuit Using a New Shape GT Cut Quartz Crystal Resonator

Oscillation Frequency Characteristics in a CMOS Oscillator Circuit Using a New Shape GT Cut Quartz Crystal Resonator

Internally Temperature Compensated Crystal Oscillators Employing a New Shape GT Cut Quartz Crystal Resonator

Internally Temperature Compensated Crystal Oscillators Employing a New Shape GT Cut Quartz Crystal Resonator

An analysis of electrical equivalent circuit constants for a GT cut quartz crystal resonator with supporting portions at both ends

AbstractA GT cut quartz crystal resonator with supporting portions at both ends has superior frequency‐temperature characteristics similar to the conventional rectangular GT plate. It was reported that it is a high‐Q resonator with a small equivalent series resistance from experiments [1, 2]. In this paper, the electrical equivalent circuit constants of the GT cut quartz crystal resonator with supporting portions at both ends is described. First, the equivalent circuit of the GT cut quartz crystal resonator is studied. It is found that the main vibration and the subvibration can be treated approximately as a single‐mode resonator since the coupling coefficient is only about 3 percent. Next, the relationship of the motional inductance L1, motional capacitance C1, parallel capacitance CO, capacitance ratio r1, and electromechanical coupling coefficient Kvl of the main vibration to the plate thickness electrode area and cut angle ϕ is found theoretically. Also found is the relationship of the motional inductance L2 of the subvibration and the plate thickness. These relationships are compared with the experiments. Calculated and measured results agreed well. Hence, the present analytical results are useful for design of a resonator with a new frequency.

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.

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.

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.