| Quartz resonator has a significant force-sensitive effect under the action of force,which is applied in the field of modern digital measurement and control.However,because of the frequency drift caused by temperature changes and other factors,and the lower force sensitivity of the quartz crystal resonators,its application is limited in the force(or stress)detection control applications.In order to further improve the force-frequency sensitivity of quartz resonators and widen the application field of quartz resonators,a new multi-electrode intergrated quartz force-sensitive resonator cluster is proposed and designed breaking the traditional method of single pair of electrodes composed of resonator on a quartz wa fe r.According to the theory of piezoelectric crystal and the anisotropy of quartz,the force-frequency sensitive mechanism,freq uency stability,temperature-freq uency characteristics and application exploration of resonator clusters on the substrate are advanced on the basis of studying the relationship between piezoelectric characteristics,vibration characteristics,elastic wave propagation characteristics,electrode mass effect,stress distribution in the wafer and resonator frequency.The research has laid the fo undation for the later applicatio n and development.Firstly,the resonance energy distribution of thickness-shear quartz crystal is derived and calculated using the energy trapping theory of crystal vibration.It provides a design basis for designing a cluster of resonators on the same circular wafer.Secondly,a three-dimensional finite element analysis model of quartz crystal resonator cluster is constructed by finite element analysis(FEA).The energy trapping effect and parasitic vibration interference of quartz crystal resonator cluster are analyzed intuitively to guide the optimal design of the structural parameters of the cluster.On the basis of the above work,the quartz resonator clusters with different structural parameters are designed.The impedance characteristics,electrical parameters,frequency stability and temperature-frequency characteristics of quartz resonator clusters are tested.Under atmospheric conditions,the frequency stability can reach 10-10 orders of magnitude.Frequency-temperature characteristics can be described by c ubic curves with good consiste nc y.Based on the elastic mechanics method,stress distribution is derived and calculated in circular quartz wafer by radial force and force frequency characteristics of each point in the disk are obtained.The experimental results show that the sensitivity of the quartz re so nator cluster is obvio usly better than the traditio nal single electrode resonator,and the maximum sensitivity coefficient of a single resonator in a quartz resonator cluster is up to 1672 Hz/N?Using modern electronic technology and signal and information processing technolbgy,the processing and fusion of resonator cluster signals are designed and realized.The output frequency signals of the resonator cluster are subtracted from each other to form beat frequency signals that suppress tenperature and other interference factors using the common mode rejection principle.The beat frequency signals are superimposed to improve the overall force-sensitivity of the quartz crystal resonator cluster.The overall force sensitivity coefficient of the resonator cluster is 7333 Hz/N.The processing and fusion scheme of the resonator cluster signal lays a good fo undation for the application of quartz reso nator cluster.Based on the quartz resonator cluster,a digital tilt sensor and acceleratio n se nsor are developed.The prototype is designed and their performance is tested.After the later improvement,it can be applied to the military and civilian attitude measurement and control fields such as aircraft,ships and towers. |
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