• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.251-251
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• 2008

In this work, appropriate corrugated structure is suggested to increase resonant frequency of resonators. Micro beam resonators based on polycrystalline 3C-SiC films which have a two-side corrugation along the length of beams were simulated by finite element method and compared to a same - size flat rectangular. With the dimension of $36\times12\times0.5{\mu}m^3$, the flat cantilever has resonant frequency of 746 kHz. Meanwhile, with this size only corrugation width of $6{\mu}m$ and depth of $0.4{\mu}m$, the corrugated cantilever reaches the resonant frequency at 1.252 MHz, and is 68% larger than that of flat type.

• Journal of KSNVE
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• v.8 no.1
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• pp.49-56
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• 1998

Although the fundamental resonance frequency of a Helmholts resonator is mainly determined by the volume of the resonator and the size of the hole, it is also affected by the position of the hole and the shape of the resonator. In this study, the inertial end corrections and the fundamental resonance frequencies of concentric pipe resonators are estimated for various positions of the hole and shapes of the resonator by using the 3-D analysis. For an effective noise reduction in concentric pipe resonators with several holes, an optimal spatial hole-distribution is proposed based on the calculated transmission loss for various hole-distributions and sizes of holes.

• 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.

• Proceedings of the IEEK Conference
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• 2001.06a
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• pp.245-248
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• 2001

In this paper, we have investigated the design technique and fabricated the surface acoustic wave (SAW) filter for duplexer, which consists of Tx. and Rx. filter, and antenna terminal. For Tx. and Rx. bandpass filters we used the one-port SAW resonators with n-section ladder structure. The structure is composed of couples of series-arm resonators and parallel-arm resonators. RF filter using ladder structure was designed and fabricated on 36$^{\circ}$Y-X LiTaO$_3$ substrates. Designed filters, insertion loss is less than 1.5dB, the bandwidth is more than 25MHz, rejection band level is less than -30dB and center frequency is 820MHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.278-282
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• 2003

The rapid growth of wireless and mobile communications has stimulated the development of multilayer filter technology. In this paper, one type of aperture-coupled microstrip interdigital-loop resonators in a multilayer structure are proposed and investigated for the applications to the design of a new class of compact microstrip bandpass filter. The new filter configuration consists of two arrays of microstrip interdigital-loop resonators that can be coupled through the apertures on the common ground plane. Depending on the arrangement of the apertures, different filtering characteristics can easily be realized. The results of measurement are almost similar to those of simulation.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1406-1407
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• 2008

In this paper, a micro balanced filter in magnetically coupled LC resonators is proposed, designed, simulated by using FR-4 PCB substrate for low cost, small volume IEEE 802. 11a wireless LAN application. Two pair of coupled LC resonators using magnetic coupling of embedded inductors are applied to obtain bandpass transmission response and improve their phase and magnitude imbalance characteristics. In addition, high dielectric composite film is applied to fabricate the high Q MIM capacitors with small size and high capacitance density. It has an insertion loss of 1.4 dB, a return loss of 10 dB, a phase imbalance of 0.25 degree, and magnitude imbalance of 0.17 dB at frequency bandwidth of 200 MHz ranged from 5.15 GHz to 5.35 GHz, respectively. The proposed balanced filter has a small volume of $1.1mm{\times}1.3mm{\times}0.6mm$ (height).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.570-572
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• 2012

In this paper, a three-dimensional (3-D) low-loss and wide-band BPF based on low-temperature co-fired ceramic (LTCC) has been presented for mm-wave wireless communication applications. The proposed BPF is designed in a 6-layer LTCC substrate. The double patch resonators are fully integrated into the LTCC dielectrics and vertical via and planar CPW transitions are designed for interconnection between embedded resonators and in/output ports and MMICs, respectively. The designed BPF was fabricated in a 6-layer LTCC dielectric. The fabricated BPF shows a centre frequency (fc) of 53.23 GHz and a 3dB bandwidth of 14.01 % from 49.5 to 56.9 GHz (7.46 GHz). An insertion loss of -1.56 dB at fc and return losses below -10 dB are achieved. Its whole size is $4.7{\times}1.7{\times}0.684mm^3$.

• Journal of the Korean Magnetics Society
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• v.25 no.1
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• pp.27-30
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• 2015

In this study, the LC resonators were fabricated with ferrite cores and external capacitors, and then their characteristics were investigated for the purpose of developing new displacement sensor. The frequency dependence of impedance of single resonator was estimated. There were two resonance peaks on the impedance spectrum; one by self inductance and the other by mutual inductance. The resonance frequency was shifted linearly in direct proportion to displacement of the resonator showing the proposed device, a pair of LC resonators, could be used a precision displacement sensor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.178-183
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• 2003

This paper deals with transmission loss characteristics of the panel type silencer to control low frequency noise. The panel type silencer is composed of many Helmholtz resonators by side branch. Each resonator has high transmission loss on the narrow band of its resonance frequency. Direct arrangement of the resonators increases mainly the magnitude of transmission loss. If we arrange the resonators in a row, the peak and band of transmission loss are increased. This makes the resonator array to have high transmission loss in the broader band. Using this idea, we design a silencer that has broader band characteristics and smaller volume.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.237-243
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• 2010

A wireless power transfer system based on magnetically coupled two resonators is analysed using the filter theory. Design equations for each lumped parameter circuit components are derived. As a result, change of coupling coefficient between the resonators and/or change of load resistance are easily responded. Effect of circuit loss to the design theory is also addressed. After designing a power transfer system, a real system is constructed using spiral and loop coils. Dependence of circuit elements on their dimensions is measured in advance and used to cope with the designed element values. Simulated response by use of designed element values and measured result are compared, indicating the validity of the theory.