Papers by Keyword: Resonant Frequency

Abstract: This paper introduced a novel actuator constructed by a flexible torsion spring with molded silicone rubber. The torsion spring is fixed at the ends to obtain the high rigidity and is molded by a silicone rubber material to achieve the high reliability. The actuator has the resonant frequency of f₀=59Hz on the scanning direction and f_β =239Hz on the longitude direction. The maximal stress is 0.168MPa compared to the yield strength of 4.3MPa and the predicted safety factor is 25.6.

Abstract: e. The formalism of wireless power transmission is discussed coupled mode theory can be used to describe the resonance process. According to the changing process of input impedance and input current to describe the demarcate of resonant frequency. also demonstrate that loop circuits have an important effect of the resonant magnetic field distribution.

Abstract: The constant matrix and piezoelectric equations of quartz crystal material are introduced in this paper. Vibration characteristics of quartz crystal is analyzed under several important vibration mode and coupled modes are explained. At last, some measures to suppress the QCM vibration coupling is presented.

Abstract: The effect of inner-rod oblique misalignment in a 9-GHz open coaxial resonator is studied by means of the software CST microwave studio. Results show that the oblique eccentric between the inner rod and outer wall have substantial influences on the field profile, resonant frequency, and Q factors of an open coaxial resonator. And the oblique misalignment has more serious effect than the parallel misalignment. So in the practical of engineering applications, we should try to avoid the occurrence of eccentric between the inner rod and outer wall during to technological factors.

Abstract: Metal Rubber(MR) vibration isolator is a new type of isolator developed to overcome the fatal aging phenomenon of current rubber isolator. It has broad practical application in the military, such as aerospace. In this paper, the fatigue life experiment is conducted to MR vibration isolator, and resonant frequency and resonant accelerate transmissibility are chose as degradation parameters. It’s found that MR vibration isolator possesses jump phenomenon; resonant frequency and resonant transmissibility increase quickly to the maximum, then attenuate slowly with the increasing number of vibration. This provides fundamental basis for the design and application research of MR vibration isolators.

Abstract: Microwave cavity with complicated structure and rubidium gas is studied by mode matching method. By calculating resonant frequencies of HE₁₁₁ mode under different parameters, main factors that influence resonant frequency is studied. In addition, the resonant frequency of HE₁₁₁ mode is compared with commercial software (CST) results. The computed results show good agreement with CST simulations. It can be seen that this method is of high credibility and efficiency. This paper is of great significance for cavity design and theoretical perfection.

Abstract: Temperature is one of the most important factors affecting the accuracy of micromechanical silicon resonant accelerometer (SRA). In order to reduce the temperature sensitivity and improve the sensor performance, a new method of temperature self-compensation for SRA is presented in this paper. Utilizing the differential structure of SRA, the temperature compensation for bias and scale factor can be realized simultaneously in this method. Moreover, because no temperature sensor is needed in this method, the error in temperature measurement due to the temperature gradient between the mechanical sensitive structure and temperature sensor is avoided, and the precision of temperature compensation for SRA can be further improved. The test results obtained on SRA prototype which is developed by MEMS Inertial Technology Research Center show that, by employing the method of temperature self-compensation, the temperature coefficients of bias and scale factor are reduced from 3.1 mg/°C and 778 ppm/°C to 0.05 mg/°C and -9.4 ppm/°C, respectively.

Abstract: For the study of effects of perturbation, such as the change in the resonant frequency and in the other parameters of a rectangular cavity, the resonance condition, the resonant wavelength and the resonant frequency are analyzed in this paper, with the help of perturbation method in a resonance cavity of the reflection type. The relation is deduced in detail under two suppose conditions, which is between the resonant frequency and the dielectric constant or the permeability of the medium filled in the cavity. The accurate relation between the changes in the resonant frequency and in the dielectric constant or the permeability is established. This paper provides the scientific basis for research on the intrinsic characteristic of medium.

Abstract: Abstract. To improve energy harvesting performance, a resonance frequency tunable piezoelectric (PZT) energy harvester for vibrating applications was presented and investigated experimentally. A piezoelectric vibrational energy harvester (PVEH) consisted of a piezo-cantilever with a permanent magnet at its free-end and another excitation magnet fixed on vibration structure. The two magnets are placed with the same magnetic poles facing each other to produce repulsive force. The cantilever has dimensions of 70x10x0.6mm³, clamped 10mm, and two magnets sized ø10x4mm³. The testing results show that the magnetic force, denoted by the initial separated distance between the magnetic dipoles (SDMD), exerts great influence on the generated performance. With the SDMD increasing from 15mm to 40mm, the generated voltage rises from 24.4V to 40V, and the resonant frequency increases from 33.75Hz to 38.75Hz.

Abstract: The influence of temperature’s variation upon the resonant frequency and damping of the Micro-Electro- Mechanical-System (MEMS) gyroscope’s silicon structure in the vacuum package is investigated in this article. The gyroscope’s working principle and the dual-mass decoupled gyroscope structure are introduced, the drive and sense modes’ frequencies are analyzed. The ideal models of resonant frequency and damping are established and the dominate elements of impacting the resonant frequency and damping are Young Modulus, air viscosity coefficient and ambient pressure respectively. The experiments and the results proved that the frequency model works well, and the damping model only can simulate the tendency because of the air getter’s influence.