• Title, Summary, Keyword: circulator

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A four-port stripline circulator using a single ferrite disk (단일 페라이트 공진기를 이용한 4단자 스트립라인 서큘레이터)

  • Kim, Hye-Jin;Nam, Min-Hee;Lee, Jae-Hyun
    • Journal of Satellite, Information and Communications
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    • v.4 no.2
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    • pp.52-56
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    • 2009
  • The design method of a four-port stripline circulator with a single ferrite disk is proposed using Green's function method. The four-port circulator gives the flexibility of the design of the communication system. Two cascaded three-port circulators has been used as a four-port circulator. However, if a four-port circulator with a single ferrite disk replace the present four-port circulator, then it will give less weight and volume and so has the advantage in satellite application.

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Magnetic Parameters for Ultra-high Frequency (UHF) Ferrite Circulator Design

  • Lee, Jaejin;Hong, Yang-Ki;Yun, Changhan;Lee, Woncheol;Park, Jihoon;Choi, Byoung-Chul
    • Journal of Magnetics
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    • v.19 no.4
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    • pp.399-403
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    • 2014
  • We designed an ultra-high frequency (UHF: 300MHz to 3 GHz) ferrite circulator to investigate magnetic parameters, which are suitable for a self-biased GHz circulator design. The size of the ferrite disk was 1.58 mm in thickness and 13.5 mm in diameter. The saturation magnetization ($4{\pi}M_s$) of 3900 Gauss, internal magnetic field ($H_{in}$) of 1 kOe, and ferromagnetic linewidth (${\Delta}H$) of 354 Oe were used in circulator performance simulation. The simulation results show the isolation of 36.4 dB and insertion loss of 2.76 dB at 2.6 GHz and were compared to measured results. A Ni-Zn ferrite circulator was fabricated based on the above design parameters. An out-of-plane DC magnetic field ($H_0$) of 4.8 kOe was applied to the fabricated circulator to measure isolation, insertion loss, and bandwidth. Experimental magnetic parameters for the ferrite were $H_{in}$ of about 1.33 kOe and $4{\pi}M_s$ of 3935 Gauss. The isolation 43.9 dB and insertion loss of 5.6 dB measured at 2.5 GHz are in close agreement with the simulated results of the designed ferrite circulator. Based on the simulated and experimental results, we demonstrate that the following magnetic parameters are suitable for 2 GHz self-biased circulator design: $4{\pi}M_r$ of 3900 Gauss, $H_a$ of 4.5 kOe, $H_c$ greater than 3.4 kOe, and ${\Delta}H$ of 50 Oe.

Improvement Effect of Air Diffusion and Indoor Thermal Environment with the Application of Air Circulator for Cooling Purpose (에어 서큘레이터의 냉방 적용 시 실내 기류 확산 및 온열환경 개선 효과)

  • Rhee, Kyu-Nam;Jung, Gun-Joo
    • 한국건축친환경설비학회 논문집
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    • v.11 no.3
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    • pp.246-252
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    • 2017
  • Space cooling with air conditioners often results in non-uniform thermal environment and over-cooling problems because it is difficult to circulate the cooled air in the entire space. These problems may cause not only thermal discomfort but also increased cooling energy. To overcome these problems, air circulators are suggested as an alternative to compensate the shortcoming of air conditioners by improving the air diffusion in the conditioned space. However, few studies have been conducted to quantitatively evaluate the improvement of cooling performance with the air circulator. In this study, the effect of the air circulator on the thermal environment was investigated with experiments in the private office. Air diffusion performance was evaluated with the effective draught temperature ($T_{ed}$) and thermal comfort was investigated with the PMV index and ASHRAE SET(Standard Effective Temperature) model. The experimental results showed that the air circulator is effective for mitigating the spatial difference in air temperature and speed, improving thermal uniformity in the conditioned room. The operation of the air circulator allows Ted to be between $-1.5^{\circ}C$ and $+1.0^{\circ}C$, which leads to improved air diffusion performance as well as thermal comfort. It was also found that the air circulator contributes to the improved thermal comfort by means of elevated air speed.

The Optical Circulator Using FBG (FBG를 이용한 광 써큘레이터에 관한 연구)

  • Kim, Kee-Joong;Son, Yong-Hwan;Jung, Jin-Ho
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.122-125
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    • 2003
  • In this paper, we propose the optical circulator using OADM(optical add-drop multiplexer) and consider its output characteristics by computer simulation. The results obtained by computer simulation, show that the proposed optical circulator operates in WDM wavelength ranges (1530nm -1560nm) well.

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A Study on Development of the High-Power Low-Loss Waveguide Circulator for Ka-band Millimeter-Wave Seeker (밀리미터파대역(Ka-대역)탐색기용 고 전력 저 손실 도파관 순환기 개발에 관한 연구)

  • Jung, Chae-Hyun;Han, Sung-Min;Baek, Jong-Gyun;Lee, Kook-Joo;Park, Chang-Hyun;Kwon, Jun-Beom
    • The Journal of The Institute of Internet, Broadcasting and Communication
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    • v.17 no.6
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    • pp.83-88
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    • 2017
  • In this paper, a 3-port waveguide circulator of Ka-band millimeter-wave for isolation between transmit channel and receive channel at high power transmit mode is designed and fabricated for the seeker of the guided missile and circulator performance is verified through the S-parameter, high power and operation temperature test. At the configuration design, interface design between a seeker antenna and the circulator is considered and half-height of standard waveguide is applied for minimum and light weight body. The shape of permanent magnet and ferrite is optimized by simulation and tuning dielectrics at each port are placed for the best performance. In Fc(center frequency)${\pm}1000MHz$, designed waveguide circulator has below -20 dB return loss, below 0.5 dB insertion loss and below -23 dB isolation. It is found that circulator characteristics is similar to design results.

An analysis of arbitrarily shaped planar circulators (임의의 모양을 갖는 평면형 서큘레이터의 해석)

  • 정중성;김병욱;전동석;윤상원;장익수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.75-84
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    • 1996
  • planar circulator swith arbitrarily shaped ferrite resonators are analyzed in this paper. First, resonant frequencies and field distributions for the magnetized ferrite resonator are obtained using finite element method (FEM). Then the RF voltage distributions and other circuit parameters of the circulator which is formed by connecting three suitable transmission lines ot the ferrite resonator are derived from the green function . To remove the spurious solutions in analyzing the ferrite resonator, the results of eigenvalue analysis by node based FEM are comapred with the edge based fEM. The green function is expanded in terms of normalized eigenfunctions of th ecorresponding wave equation. Circulator parameters for circular disk resonator are clculated and compared with the analytical results. The experimental data for the designed circulator using hexagonal reosnator in the 850 MHz frequency range agree well iwth the simulated data.

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Broadband Microstrip Y-Junction Circulator (광대역 마이크로스트립 Y형 써어큘레이터)

  • 김봉열;이용훈
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.13 no.1
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    • pp.16-22
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    • 1976
  • Broadband operation of Y-junction microstrip circulator withlnonreciprocal device is predicteg by Rosenbaum using Bosma's Green function analysis. The anslysis has been modified to enable the scattering matrix and therefore the circulator bandwidth, to be found. The width of the coupling transmission lines is found to be a significant design parameter${\psi}$. A comparison of experimental and theoretical results for the 3-port junction shows that wide lines and a smaller 7.5U than usual disk radius can be used to obtain broadband operation. Circulator operates in the frequency band 5-11 GHz. The obtained maximum insertion loss is 0.5dB and the isolation is more than 15dB.

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The fabrication of 2GHz Circulator using $Y_{3-2x}$ $Ca_x$S $n_x$F $e_{3.5}$A $l_{1.5}$ $O_{12}$ Garnet ( $Y_{3-2x}$ $Ca_x$S $n_x$F $e_{3.5}$A $l_{1.5}$ $O_{12}$ 가네트 자성체를 이용한 2GHz 대 서큘레이터 구현)

  • 박정래;김태홍;전동석;한진우
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.12
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    • pp.14-21
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    • 1997
  • This study was conducte dto fabricate 2GHz circulator using Ca,Sn substituted UIG(yttrium iron garnet)ceramics. When the electric, magnetic and microwave properties were measured in Ca, Sn substituted YIG, the measured perimittivity and perfmeability in microwave frequencies were 16.25, 0.8964. For $Y_{2.4}$C $a_{0.3}$A $n_{0.3}$F $e_{3.5}$A $l_{1.5}$ $O_{12}$ garnet ceramics sintered at 1400.deg. C, the ferrimagnetic resonance line width (.DELTA.H) at 10GHz was 53 Oe and saturation magnetization was 375G. The strip-line circulator was simulated with 3-D FEM (finite element method) software and designed at the center frequency of 2GHz. The fabricated strip-line junction circulator using above YIG ceramics had insertion loss of 1.271dB, return loss of 23.843dB, isolation of 21.751dB at the center frequency 1.855GHz.z.z.z.z.z.z.

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Design and Fabrication of Stripline Circulator Including Structure of Ring Resonator (환형 공진기 구조를 갖는 스트립라인 서큘레이터 설계 및 제작)

  • 김동현;양두영
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.6
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    • pp.866-878
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    • 1999
  • In this paper, stripline circulator including a ferrite resonator which is consisted of a circular disk and two annuli disks is designed and fabricated. Using RGF(Recursive Green Function) technique, electromagnetic field of port and input impedance is presented. The circulator characteristics are compared according to the ferrite arrangement, bias field intensity and port width. The pass-band frequency of the fabricated circulator using the designed data is from 1.55 GHz to 2.95 GHz, the reflection coefficient $S_{11}$ of input port is -30 dB, and the transmission coefficient $S_{21}$ between input port and isolation port is -28 dB at resonating point 2.38 GHz.

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3-Port Circulator for X-Band Radar (X-Band 레이더를 위한 3-포트 서큘레이터)

  • Yoon, Sung-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.355-362
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    • 2015
  • In this study, we have fabricated 9.385[GHz] circulator that is composed of WR112 waveguide and Ferrite for X-band radar. For designing Ferrite, B/R mode(Below Resonance mode) was used and calculated the condition of 120 degree rotation of the electric field in Ferrite and calculated internal DC magnetic field and external DC magnetic field. Also, dielectric materials of the same shape with Ferrite was filled between two Ferrite for improving the performance of the circulator, including impedance matching, bandwidth, quality factor, insertion loss. To obtain optimum shape of the Ferrite and dielectric material, we used CST MWS. Simulation result of the circulator is that 1.02 : 1 VSWR, -40dB isolation, 0.2dB insertion loss and measurement result is that 1.03 : 1, -38dB, 1.2dB at 9.385[GHz]. We can get good agreement at isolation and VSWR, but insertion loss was 1 dB great than simulation result.