THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. 2015 Dec.; 26(12), 1044 1049. http://dx.doi.org/10.5515/kjkiees.2015.26.12.1044 ISSN 1226-3133 (Print) ISSN 2288-226X (Online) Analysis of Antenna Isolation Using Decoupling Structure 이정훈 김지훈 김민기 김형훈 김형동 Junghun Lee Jihoon Kim Min-Gi Kim Hyung-Hoon Kim* Hyeong-Dong Kim 요약 (isolating resonator). Wi-Fi (2.4 2.5 GHz),. Wi-Fi., (C D). Abstract In this paper, isolation enhanced antenna using isolating resonator was proposed. Two loop type antennas were designed to operate at Wi-Fi band(2.4 2.5 GHz), in symmetry to the center, and are closely located to each other. In order to enhance isolation characteristics at Wi-Fi bands, isolating resonator was designed between the two loop type antennas. The proposed isolating resonator is a slot type antenna that enhances isolation with the control of the size, and by adjusting the value of capacitor(c D) the resonant frequency of the isolating resonator can easily be adjusted to enhance isolation characteristic at the target frequency. Key words: Antenna Isolation, Isolation Network, MIMO, Decoupling Resonator, Three Port Network. 서론 MIMO, [1],[2]. MIMO, LTE, USB dongle., [3],[4].,, [5],[6]., stub EBG(Electromagnetic Band- Gap), Neutralization line, suspended-line [7]. Stub EBG, 2014 (ICT) (Department of Electronics and Computer Engineering, Hanyang University) * (Biomedical Engineering, Kwangju Women's University) Manuscript received April 21, 2015 ; Revised November 26, 2015 ; Accepted December 7, 2015. (ID No. 20150421-033) Corresponding Author: Hyeong-Dong Kim (e-mail: hdkim@hanyang.ac.kr) 1044 c Copyright The Korean Institute of Electromagnetic Engineering and Science. All Rights Reserved.
[8], Neutralization-line, suspended-line,. slot (isolating resonator), LTE, USB dongle.. 안테나구조및동작원리분석 1, 2,. 1 mm FR4(ε r =4.4, tanδ=0.02), PCB 70 50 mm 2, PCB. 2 7 mm 2, Wi- Fi(2.4 2.5 GHz). feed radiation loop 10 mm. C F1, C F2, C R1, C R2. C F1,2 0.2 pf, C R1,2 0.1 pf. 5 L mm 2, port #1 19 mm, port #2 4 mm., 2. 5 mm, L port #1 port #2. (C D ). 3 return loss. S 11 S 22 (a) (a) Reference antenna (b) (b) Proposed antenna 그림 1. Fig. 1. The structure of the reference antenna and the proposed antenna. S 22. return loss, port 1 port 2. 5, L. 8 db, L 2 mm, 2.7 mm, 3.2 mm 21 db, 28 db, 33 db. port 1045
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 12, Dec. 2015. (a) Port #1 (a) Port #1 antenna (a) S 13 (b) S 23 그림 4. L port #1 - port #3, port #2 - port #3 coupling Fig. 4. Coupling change of port #1 - port #3 and port #2 - port #3 with L variation. (b) Port #2 (b) Port #2 antenna and isolating resonator 그림 2. Fig. 2. The detail of the proposed antenna and isolating resonator. 그림 5. L Fig. 5. Isolation was enhanced by increasing the height L. 그림 3. return loss Fig. 3. The return loss of the reference antenna and the proposed antenna. #3, port #1 port #3, port #2 port #3 coupling 4. (1) (2) 그림 6. (C D) Fig. 6. Resonant frequency change of isolating resonator with capacitance(c D) variation. 1046
3 Three port network (1) Z' 12 port 1 port 2 isolation. Port 1 (Z 13 ), port 2 (Z 32 ) (2) Z' 12 0, 1 2. 6 (C D ). 0.85 pf, 0.75 pf, 0.65 pf (a) (a) Reference antenna 2.3 GHz, 2.5 GHz, 2.8 GHz. 7. Port #1 port #2 PCB port #1., port #1 PCB port #2.,, port #1 PCB port #2,. MIMO., (C D ).. 측정및논의 (b) (b) Proposed antenna 그림 7. Fig. 7. The current distribution of the reference antenna and the proposed antenna. 8., L 12 db, 17 db, 27dB. 7 db, L 3.2 mm 27 db20 db, (C D ). 5, 6. 9 2.45 GHz. 1047
THE JOURNAL OF KOREAN INSTITUTE OF ELECTROMAGNETIC ENGINEERING AND SCIENCE. vol. 26, no. 12, Dec. 2015.., L (C D )., C D,. (a) L (b) (C D) (a) Measured isolation characteristics change with resteristics change with res- (b) Measured isolation characonator variation(l) onator variation(c D) 그림 8. Fig. 8. Measured isolation characteristics change with resonator variation. (a) (a) W/O decoupling resonator (b) (b) With decoupling resonator 그림 9. Fig. 9. The radiation pattern of the reference antenna and the proposed antenna.. 결론. Wi-Fi(2.4 2.5 GHz) PCB. 28 mm References [1] Michael A. Jensen, Jon W. Wallace, "A review of antennas and propagation for MIMO wireless communications", IEEE Transactions on Antennas Propagation, vol. 52, no. 11, pp. 2810-2824, Nov. 2004. [2] D. Gesbert, M. Shafi, D.-S. Shiu, P. Smith and A. Naguib, "From theory to practice: An overview of MIMO space-time coded wireless systems", IEEE J. Sel. Areas Communications, vol. 21, no. 3, pp. 281-302, Apr. 2003. [3] A. C. K. Mak, C. R. Rowell, and R. D. Murch, "Isolation enhancement between two closely packed antennas", IE- EE Trans. Antennas Propag., vol. 56, no. 11, pp. 3411-3419, Nov. 2008. [4] A. Diallo, C. Luxey, P. L. THuc, R. Staraj, and G. Kossiavas, "Study and reduction of the mutual coupling between two mobile phone PIFAs operating in the DCS- 1800 and UMTS bands", IEEE Trans. Antennas Propag., vol. 54, no. 11, pp. 3063-3073, Nov. 2006. [5] D. Assanuk, M. Uthansakul, and P. Ulthansakul, "Optimal antenna positions on mobile terminal for 4 4 MIMO systems", Electrical Engineering / Electrics, Computer, Telecommunications and Information Technology, 2009. ECTI-CON 2009. 6 th International Conference on. [6] Kin-Lu Wong, Jui-Hung Chou, Chia-Lun Tang, and Shih- Huang Yeh K, "Integrated internal GSM/DCS and W- LAN atennnas with optimized isolation for a PDA phone", Microwave Opt Technol Lett., vol. 46, no. 4, pp. 323-326, Aug. 2005. 1048
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