• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2392-2394
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• 2005

This paper presents a tuneable bandstop resonator with two possible configurations, it can be used to tune its center frequency, or it can be used to tune its bandwidth. The tuneable bandstop resonator has potential application in microwave communications receivers, where it can be used to tune out interfering signals. The proposed resonator is comb actuated, where the resonator's displacement produces different values of frequency or bandwidth, this is achieved by decoupling electromagnetic energy from a main transmission line. The proposed fabrication process for the resonator is by anodic bonding pyrex glass and tow resistivity silicon, where the comb resonator structure is patterned by deep reactive ion etching (DRIE). This paper presents the resonator and actuator design in both configurations, as well as the fabrication process intended for its development.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.11
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• pp.81-87
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• 2000

A new resonator that is fabricated by single polysilicon layer process is presented. The resonator can move in two orthogonal direction on the plane parallel to the substrate. And the resonant frequencies of the two modes are intrinsically designed to be identical since the overall structure of the resonator is symmetric about the two directions of motion. Since the resonator ideally has two identical vibration mode, it can be applied to various micro-devices that requires multi DOF motion, especially to microgyroscopes. To investigate the feasibility of application of the resonator, dynamic model of the resonator including the nonlinear behavior of driving electrodes is derived and evaluated with the fabricated one, and the self-tuning characteristics are proved though experiments.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.9-16
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• 2008

Ribbed birch (Betula costata Trautv.), Japanese larch (Larix kaempferi (Lamb.) Carr.), and tulip tree (Liriodendron tulipifera L.), were used as experimental specimens to measure the sound absorption coefficient with various resonator types, regular resonator (Type-R), eccentric resonator (Type-E), aligned resonator (Type-A), and screwed resonator (Type-S). Resonators consisted of the simple perforation by hand drilling. Sound absorption performances of the resonators installed perforations were better than those of untreated specimens. They were varied with the resonator's type and wood species. Increased area by a wood screw gave no significant change on the sound absorption.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.6
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• pp.630-636
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• 2016

In this paper, a novel triple-mode cavity structure, designed for compactness and operating at 850 MHz, is analyzed. A cylindrical dielectric resonator is loaded into a metallic cylindrical cavity. Previous study has been focused on the analysis of the cylindrical dielectric resonator, but in this paper, the effect of the cylindrical metallic cavity has been analyzed. Enclosing the dielectric resonator inside the metallic cavity increases the resonant frequency of the dielectric resonator; however, this increases the quality factor and introduces the possibility of installing coupling screws. The principle of generation of triple-mode was investigated by parametric analysis. The generated triple-mode is TE011 mode and two orthogonally generated HEM121 modes. By adjusting the radius of the dielectric resonator, the height of the dielectric resonator, or the radius of the cylindrical metallic cavity, three modes could be coincided. However, the height of the metallic cavity keeps three modes separated. The mode characteristics of the proposed cavity are analyzed using a full-wave electromagnetic (EM) simulation. The proposed triple-mode cavity could be developed to triple-mode filter using a coupling screw, and the commercial application for the miniaturized filter below 1 GHz could be expected.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.3
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• pp.34-40
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• 2008

Acoustic design parameters of a half-wave resonator are studied experimentally for acoustic stability in a model chamber. According to the standard acoustic-test procedures, acoustic-pressure signals are measured. Quantitative acoustic properties of damping factor and sound absorption coefficient are evaluated and thereby, the acoustic-damping capacity of the resonator is examined. The diameter and the number of a half-wave resonator, its distribution, and the diameter of an enclosure are selected as the design parameters for optimal tuning of the resonator. Aroustic-damping capacity of the resonator increases with its diameter. When the open-area ratio of the resonator exceeds the optimum value, over-damping appears, leading to the decrease in the peak absorption coefficient and the broadening of absorption bandwidth. As the resonator diameter increases, optimum open-area ratio decreases.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.10
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• pp.947-954
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• 2013

This article focuses on a hemispherical resonator gyro driven by the Coriolis effect. The operational principle of resonator gyros and mathematical models are introduced. These models are useful to explain the behavior of a resonator and to design controllers. Several control tests of a resonator have been done. A resonator has been excited by electromagnets controlled by a computer. Its amplitude has been adjusted by a PI control. The transient response is matched with a simulation result based on a mathematical model. A vibrating pattern may drift due to non-uniform factors of a resonator. The drift of the vibrating pattern is controlled and aligned to a reference direction by a PI control. These results are very useful to understand the behavior of resonator gyros and to design advanced control algorithm for better performance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1643-1647
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• 2000

The intake noise of an automobile induced by firing of an engine accompanies acoustic resonances of ducts of an intake system. Conventionally, the adoption of the Helmholtz type resonator was one of possible ways to eliminate the booming noise due to acoustic resonances of air ducts. Although the Helmholtz type resonator is convenient to attenuate the intake noise of an automobile, the usage of the Helmholtz type resonator requires cost increase or big engine room space. Therefore, reduction of the number of the resonators or the volume of the resonators is essential to increase the value of an automobile. To meet these requirements, other types of resonator are suggested instead of the Helmholtz type resonator. The effectiveness of the suggested resonators is compared considering noise reduction ability, effect to the engine performance and size of each resonator.

• ETRI Journal
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• v.28 no.5
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• pp.607-614
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• 2006

This paper presents a new class of microstrip slow-wave open-loop resonator filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends loaded with triangular and rectangular ends is described, leading to the invention of a microstrip slow-wave open-loop resonator. Two-resonator and four-resonator bandpass filters are designed at the operating frequency of about 2 GHz, and a bandwidth of 60 MHz. The size of the slow-wave open-loop resonator is optimized from the standpoint of the unloaded Q-factor. The filters are not only compact in size due to the slow-wave effect, but also have a wider upper stopband resulting from the dispersion effect. The filter designs of this type are described in details. The experimental results are demonstrated and discussed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.71-79
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• 2008

A helmholtz resonator has been widely used for the purpose of suppressing the low frequency noises propagated from various heat and fluid machineries. However, the conventional resonator has demerits that the effective absorption bandwidth is narrow and the absorption performance is not so outstanding in the only limited configurations of neck and cavity as well. In order to overcome these problems, in this paper, a resonator with perforated neck is proposed. The absorption performances of the resonator are measured by two-microphone method and estimated by transfer matrix method. The measured values of normal absorption coefficients agree well with the estimated values. By introducing the perforated plates at the neck of a resonator, it is shown that the absorption performance have been significantly improved.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.136-140
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• 2002

In this paper, newly constructed 5.6 ㎓ ring resonator by using a T-Junction and a parallel transmission line. The resonator's size reduced twice more than a current ring and a hair-pin resonator at this paper's center frequency The loaded Q value is 240∼250 at center frequency. also, It was explained by RLC equivalent equation for the resonator.