• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.78-81
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• 2002

This paper describes on the design structure and development temperature stable strip-line junction isolator operating in above resonance mode. Temperature characteristics of isolator depend on magnet, YIG(Yttium Iron Garnet) ferrite, and conductor etc. These require temperature stability and possible methods of compensation for the temperature dependent effects. In this paper, the analysis and measurement of the temperature characteristics were carried out for the material isolator prototype. The bandwidth of isolator was expended and the center frequency shift was reduced in temperature range of -20∼8O$^{\circ}C$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1404-1408
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• 2006

In this paper, a hybrid-type vibration isolator which has air chamber(spring) and viscous damper in series is developed. The developed vibration isolator is designed to perform 3 following functions : spring function for normal operating conditions, damping function to reduce an impact for sudden move of upper beam, and finally leveling function. Based on the given natural frequency and damping factor, the design procedure is proposed. The performance of the developed isolator is tested by measuring stiffness and damping.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.12
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• pp.1075-1078
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• 2002

This paper describes on the design structure and development of temperature stable strip-line function isolator operating In above resonance mode. Temperature characteristics of isolator depend on magnet, YIG(Yttium Iron Garnet) ferrite, and conductor etc. These require temperature stability and possible methods of compensation for the temperature dependent effects. In this paper, the analysis and measurement of the temperature characteristics were carried out for the material isolator prototype. The bandwidth of isolator was expended and the frequency shift at center was reduced in the temperature range of -20∼80$\^{C}$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.6
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• pp.1233-1237
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• 2011

Insertion loss, ripple, and return loss were -1.7093dB, 0.9162dB, and -24.762dB with Cellular Rx(824~849 MHz), -1.8021dB, 0.9615dB, and -22.258 with Tx(869~894 MHz), repectively. On the other hand, insertion loss, ripple, and return loss were -2.0149dB, 1.5163dB, and -34.046 dB with DCS Rx(1710~1785 MHz), -1.5894dB, 2.3742dB, and -33.058dB with Tx(1805~1880 MHz), respectively. In the particular, the attenuations in 5MHz edge of band width were -9.1399dB and -14.336dB with Cellular Rx, -7.0343dB and -5.2943dB with Cellualr Tx, respectively. The attenuations of DCS Rx from the relative Tx were -58.298dB and -65.644dB, respectively. On the other hand, those of DCS Tx from the relative Rx were -70.659dB and -50.488dB, respectively. From the aboved results, the dielectric filters for Celluar and DCS band with Isolator showed the good skirt and ripple characterics.

• Korean Journal of Optics and Photonics
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• v.14 no.2
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• pp.142-145
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• 2003

The nonreciprocal phase shift characteristics of infinite slab optical waveguides with magneto-optic materials in the cladding layer was calculated at 1.55 ${\mu}{\textrm}{m}$ for optical isolators. The infinite slab waveguide structures considered in this paper were as follows. rho magneto-optic materials used as a cladding layer were Ce:YIG and LNB(LuNdBi)$_3$(FeAl)$_{5}$)$_{12}$,). Their specific Faraday rotations Θ$_{F}$ are 4500$^{\circ}$/cm, 500$^{\circ}$/cm at wavelength 1.55 ${\mu}{\textrm}{m}$ respectively. The guiding layer with multi-quantum well structure was used, and it consists of 1.3Q and InGaAs. In order to investigate the effect of evanescent field penetrating the cadding, layer, guiding mode characteristics were calculated for the cases when the substrate is InP and air. We calculated the minimum lengths of 90$^{\circ}$ nonreciprocal phase shifters and their optimum guiding layer thicknesses in various optical waveguide structures.res.s.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.7
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• pp.8-12
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• 1989

In this paper, dielectric waveguide gratings, which can be applied to the nonreciprocal devices such as isolators, are proposed. Those grating structures can be considered as cascade connections of step discontinuities between uniform dielectric waveguides and another uniform dielectric waveguides with a ferrite layer. Therefore, the nonreciprocal scattering characteristics of such gratings can be obtained form the scattering characteristics of step discontinuities and uniform dielectric wave guides. For the periodic grating structures, band-reject characteristics can be located inside or outside the frequency range of interest. Numerical analyses are performed at 35GHz and experimental results at X-band are also presented.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.119-122
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• 2003

This paper describes characteristics for insertion losses of Isolator have an effect on material parameter. One purpose of the paper is to present insertion loss on this resonator for magnetic loss, dielectric loss, magnetic field and saturation magnetization. Another is to study the effect of propeller resonator on response characteristics. In this paper, the analysis and measurement of the response characteristics were carried out for the isolator prototype. The measurement results agreed on the simulation results and acquire insertion loss $0.18\;{\sim}\;0.24dB$, return loss 27dB, isolation 27dB and bandwidth 500MHz on this condition saturation magnetization 550G, dielectric loss 0.0004, magnetic loss 20 and dielectric constant 14.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.358-362
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• 2006

Pyro-shock generally refers to the severe mechanical transients caused by the detonation of an ordnance device on a structure. Such device on a structure, including linear explosive, and point explosive are widely used to accomplish in-flight separation of structural elements on aerospace vehicle. And they are a significant cause of launch vehicle failures. The launch vehicle being developed in Korea also uses the explosive for separation events. In this paper, the isolator equipped to small satellite launch vehicle made of PTFE(Teflon) is developed to reduce the separation shock. The test to measure dynamic stiffness of PTFE isolator is performed. This test enables us to find the frequency range of PTFE isolator. And,, pyre-shock test using explosive to evaluate the performance of PTFE isolator is executed. from this study, the isolator conformed to frequency range and load requirement is developed using PTFE instead of rubber.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.11a
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• pp.181-184
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• 2002

본 연구에서는 아이솔레이터(Isolator)의 핵심소재로 사용되는 YIG-ferrites를 수열합성법에 의해 초미세 분말로 합성하고, 합성된 분말을 원료로 사용하여 제조 공정된 YIG-ferrites 소결체의 미세구조와 전자기적 특성에 관하여 고찰하였다. 수열합성법(Hydrothermal synthesis method)으로 YIG［ $Y_3$F $e_{5}$ $O_{12}$］분말을 먼저 합성하고 Ca, V, In, Al 등을 첨가시킴으로서 $Y_{2.1}$C $a_{0.9}$ $Y_{4.4}$ $V_{0.5}$I $n_{0.05}$ $O_{12}$의 조성을 지닌 시편을 제조하였다. 초기열처리는 30$0^{\circ}C$에서 90$0^{\circ}C$의 온도 범위에서 15$0^{\circ}C$간격으로 진행하였다.. 그 결과 75$0^{\circ}C$로 초기열처리 하였을 경우 단일 YIG peak가 나타남을 알 수 있었다. 수열합성법으로 제조된 YIG 소결시편의 전자기적 특성은 일반 시약급원료를 사용하여 제조된 소결시편과 비교하여 마이크로파 특성을 평가하였다. 그밖에 YIG-ferrites의 결정성, 미세구조, 자기적 특성, 마이크로파 특성을 XRD, SEM, VSM, Network Analyzer를 이용하여 고찰하였다.여 고찰하였다.다.다.다.다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2731-2737
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• 1996

The effect of the birefringence existing in the Faraday rotator on the isolation and transmission properties of the isolator was investigated. To maintain isolation of 50dB, both the deviation of the transmission angle between input and output polarizers and the deviation of the Faraday ratation angle are permitted to .+-.0.18.deg. for birefringenceless isolator and to .+-.0.09.deg. for birefringent isolator. This means that the isolator possessing linear birefringence of 0.5.deg. requires 505 more accurage adjustment than that of no birefringence. We also simulated the characteristics of wavelength dependence for both the virefringent isolator and the birefringencelless isolator. It is also found that formward transmission loss doesn't varing much with small birefringence.