• Title/Summary/Keyword: Anechoic Chamber Test

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Broad-Band Design of Ferrite One-body EM Wave Absorbers for an Anechoic Chamber

  • Kim, Dong-Il;Son, June-Young;Park, Woo-Keun;Park, Dong-Han
    • Journal of electromagnetic engineering and science
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    • v.4 no.2
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    • pp.51-55
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    • 2004
  • With the progress of the electronics industry and radio communication technology, certain problems, such as electromagnetic interference(EMI), have arisen due to the increased use of electromagnetic(EM) waves. International organizations such as CISPR, FCC, and ANSI have provided the standards for the EM wave environment and for the countermeasure of the electromagnetic compatibility(EMC). EM wave absorbers are used for constructing an anechoic chamber to test and measure EMI and electromagnetic susceptibility(EMS). In this paper, we have designed an one-body EM(electromagnetic) wave ferrite absorber, based on the equivalent material constants method for both normally and obliquely incident waves, whose absorption abilities are superior to that of the conventional ones. The fabricated absorber has a thickness of 27.68 mm and shows an absorption ability over 20 ㏈ in the frequency from 30 MHz to 6 ㎓.

Comparison of Correlation Algorithms between GTEM Cell and Semi-Anechoic Chamber (GTEM 셀과 전자파 반-무반사실 사이의 상관관계 알고리즘 비교.분석)

  • 권종화;이애경;최형도
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.2
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    • pp.188-195
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    • 2002
  • This paper statistically verifies two correlation algorithms by comparing the data of GTEM cell to those of semi-anechoic chamber (SAC). Correlation algorithms considered in this paper are 3 and 15 position methods, which simulate the EMI test for an equipment under test (EUT) over the ground plane by using the radiated power from EUT located within GTEM cell. Also, the results obtained by two algorithms are compared with the theoretical values calculated from an ideal dipole model. From the results, it was found that the data obtained by two correlation algorithms and SAC have a strong correlation. In addition, the EMI data by 3 position method showed higher than those by 15 position method and SAC measurements.

A study on the performance test and acoustic design of interference type noise reduction device for railway noise (철도소음 저감을 위한 간섭형 방음장치 음향 설계 및 성능시험에 관한 연구)

  • Cho, Jun-Ho;Koh, Hyo-In
    • Journal of Environmental Impact Assessment
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    • v.20 no.6
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    • pp.787-795
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    • 2011
  • Noise barrier is generally used with welding of joint rail for railway noise reduction in our country. But the noise barrier for high speed railway has weak point in low frequencies about 315Hz band. In this study, For developing of Interference-type Noise Reduction Device(INRD), acoustic analysis were performed using commercial software. For verifying the improvement in the noise reduction, noise measurement before and after installing of INRD were performed in Anechoic Chamber. From these acoustic analysis and noise measurement, it was known that developed INRD has a good noise reduction performance and can be used efficiently with conventional noise barrier.

Effects of External PIM Sources on Antenna PIM Measurements

  • Kim, Jin-Tae;Cho, In-Kui;Jeong, Myung-Yung;Choy, Tae-Goo
    • ETRI Journal
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    • v.24 no.6
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    • pp.435-442
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    • 2002
  • Antenna Passive Intermodulation (PIM) level measurement results are rarely credited to be due to external signal receiving characteristics of the antennas or serious effects from external PIM sources, such as the anechoic chamber absorber and antenna tower. This paper presents an antenna PIM model for a reflected PIM measurement method. Based on the findings of null point generation and the behavior of the third order PIM values obtained by theoretical predictions and experimental results, we concluded that the results of the antenna PIM level test were influenced by the external PIM sources generated by the anechoic chamber absorber and the path differences of PIM signals coming into the antenna.

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The Characteristics of Field & Mode Distributions in a Cylindrical Reverberation Chamber (원통형 구조 전자파 잔향실 내 모드 및 필드 분포 특성)

  • 김정훈;이중근
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.5
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    • pp.431-436
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    • 2003
  • In this paper, simulation results of an electromagnetic field and mode distributions in a cylindrical reverberation chamber were presented. Reverberation chamber is an alternative test facility for a semi anechoic chamber, which is widely used for the analysis and measurement of electromagnetic interference and immunity tests. The method of computing the number of modes in a cylindrical reverberation chamber was presented and the number of modes in a cylindrical reverberation chamber with the same volume was compared with the different ratio of radius to height. The FDTD method was used to produce field characteristics inside of rectangular, right-angled isosceles triangular, and cylinder type reverberation chambers with the same test volume.

GPS Array Antenna Installation On The Rear Missile Body (위성항법 배열안테나의 유도탄 동체 후방 배치)

  • Park, Bumsoo;Ahn, Woogeun;Lee, Jangyong;Ko, Duck kon
    • Journal of Advanced Navigation Technology
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    • v.26 no.1
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    • pp.9-14
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    • 2022
  • In this paper we investigate the advantages when the GPS Antenna is installed on the rear missile body. In conventional design the GPS antenna locates on the front part of missile. However it causes degraded GPS positioning performance since the missile body blocks the GPS signals. This paper proposes the GPS array antenna design which locates on the rear part of missile body and has the tilted antenna patches to achieve the maximum area of receiving GPS signals. We simulate LOS region of receiving signals and conducted anechoic chamber test to define the effective signal receiving region. And we conduct field test and flight test to check out the enhancement of signal receiving area.

Electromagnetic Field Distribution Analysis on Reverberation Chamber using Electromagnetic Diffusion Method (전자파 확산방식을 이용한 잔향실 내부의 필드 분포 해석)

  • 이광순;이중근;정삼영
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.5
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    • pp.839-848
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    • 2000
  • This paper presents the results of an electromagnetic field analysis for a reverberation chamber that is an alternative method of a shielded anechoic chamber, which is widely used for the analysis and measurement of electromagnetic interference and immunity test. Inside the defined test volume of the rectangular and triangular type, the Schroeder Quadratic Residue Diffuser was employed. FDTD(Finite-Difference Time-Domain) simulation method was applied to produce the field characteristics inside those reverberation chambers. According to the results, field uniformities on the aforementioned two types of reverberation chambers were correlated within $\pm$3dB, and $\pm$4.4dB tolerances, and rectangular type reverberation chamber shows an independent polarization result.

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On MIMO OTA Performance Characterization Method for Mobile Devices with Multiple Antennas (MIMO 무선 성능 성능평가 방법에 관한 연구)

  • Cho, Y.S.;Kim, Y.R.;No, S.P.;Shim, H.J.;Kim, I.K.
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.5
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    • pp.84-90
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    • 2012
  • Since the major cellular data service providers in U.S, Japan as well as in Korea started the LTE (Long Term Evolution) service, there has been more strong need for the methods that can accurately measure the MIMO (Multi Input-Multi Outout) OTA (Over The Air) performance of LTE handsets because the performance of the MIMO antenna determines the packet data rates in the downlink and therefore the higher system throughput of the network. In this regard, there has been a lot discussions in 3GPP on the candidate MIMO OTA test solutions. In this paper, a faire comparison has been done for the conventional method, the Envelop Correlation Coefficient (ECC) measurements, and the anechoic chamber based MIMO OTA test solution, one of the candidate system being discussed in 3GPP. The evaluations and the comparisons are conducted by numerically and experimentally.

Experimental Characterization and Modeling for Electromagnetic Interference (EMI) Estimation due to PDP System (PDP 시스템의 EMI 예측을 위한 회로 모델링 및 실험적 검증)

  • 강종구;어영선;심종인;정주영
    • Proceedings of the IEEK Conference
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    • 2001.06b
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    • pp.173-176
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    • 2001
  • A new EMI estimation technique concerned with a PDP system is presented. A physical circuit model is developed which can fairly well describe the AC-PDP system. Then EMIs are determined by exploiting Hertzian dipole antenna model. The simulation results are experimentally verified with the test panel. The AC PDP system was measured in the frequency range of 30MHz ~ 300MHz in a semi-anechoic chamber, according to CISPR 13 code. Thereby, it is shown that the proposed technique can be usefully employed for EMI reduction.

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Performance Experiment of the Angle Deception of Cross-Eye Jamming against a Monopulse Sensor (모노펄스 센서에 대한 크로스 아이 재밍기법의 각도기만 성능 실험)

  • Jang, Yeonsoo;Park, Jintae;Lee, Changhoon;Kim, In-sun;Kim, Ghiback;Cho, Sangwang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.29 no.2
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    • pp.146-149
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    • 2018
  • A monopulse sensor is used to estimate the angle of a target with respect to each received single pulse. It is well known that the cross-eye technique can result in an angle deception effect against monopulse sensors. To verify this effect, we propose a test environment configuration for the angle deception using monopulse receiving antennae and cross-eye transmitters in an anechoic chamber. Using the proposed test environment configuration, we have measured powers of the sum and difference of the signals received by the monopulse receiving antennae when the distance of the two cross-eye transmitters is varied. Finally, the angle deception performance related to the powers of the sum and difference signals was analyzed.