• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.7
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• pp.606-612
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• 2015

This paper proposes a new design of a dual-band orthogonal-polarization microstrip antenna for V2N(Vehicle to Nomadic Device) communication system. The proposed antenna consists of a perpendicular feeding structure for utilizing orthogonal linear polarizations and an microstrip radiator which loaded by close-looped H-shape slot for obtaining dual-band operation. Due to the geometrically different loading effect of the close-looped H-shape slot for each feeding location, the orthogonally linear polarization at dual-band operation of the proposed antenna can be successfully achieved. The proposed antenna theoretically and experimentally demonstrates the vertical linear polarization at the operating frequency of 1.8 GHz and the horizontal linear polarization at the operating frequency of 2.4 GHz, respectively. The simulation and measurement results of the implemented antenna have been in good agreement with the reflection coefficients, radiation patterns, and realized antenna gains.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1097-1104
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• 2016

The infrared camera is difficult to satisfy the RE-102 specification of Mil-Std-461. Especially, in the case of UAV electronics, shielded cable is not used, so it is difficult to meet the electromagnetic compatibility standard. In the RE-102 test of the IR camera for UAV, radiated noise exceeding 30 dBuV/m was observed in the range of 50 MHz to 200 MHz. As a result of pcb em scan, peak noise which caused by the harmonic frequency of the digital control signal clock was observed. Radiated noise was reduced by up to 22.9 dBuV/m by applying the spread spectrum clock generator(SSCG) with 3 % down spreading method to the camera control clock.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.1-8
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• 2011

This study is about the limits of GTEM cell using correlation factor between the OATS(Open area Test Site) and the GTEM cell. First, the field strengths at the 10 m distance OATS and in GTEM cell to obtain the experimental correlation factor are measured. Also, the EMI limits of radiated power are derived in GTEM cell as 3 position method is inversely transformed. The field strengths that calculated from theoretical models by 3 and 15 position methods are programmed and compared with measured data at the OATS. As the EMI limits of GTEM cell is newly defined, it will be use to substitute GTEM cell for OATS to efficiently measure EMI(Electromagnetic Interference).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.9
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• pp.1108-1119
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• 2016

This paper presents the spectral analysis and radiation pattern of low-frequency electromagnetic(EM) leakage signals according to the fundamental operations of smartphones. The EM leakage signals generated by the activation of four I/O sensor modules such as a touch-screen, a camera, a microphone and a speaker are captured by the commercial near-field magnetic probe with 1cm spatial resolution. The analysis results show that the leakage of the EM wave occurs strongly around the activated I/O sensor modules, AP(Application Processor) and memory modules. Also, the distinguishable frequency characteristic is shown in each spectrum of EM leakage signals.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.558-564
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• 2021

With the recent introduction of 5G, electromagnetic radiation sources are spreading throughout life, so it is necessary to establish a citizen-centered electromagnetic safety management system. In particular, the beamforming method of the 5G antenna increases the power density measurement of electromagnetic waves by more than 10 times when the wireless base station is installed, so it is unreasonable to determine the safety by physical measurement. Therefore, it is necessary to determine the presence or absence of electromagnetic wave safety in daily life through a predictive method by calculation through systematic model analysis. In this paper, in order to check the possibility of a 5G wireless base station using an electromagnetic wave numerical analysis tool as a way to solve this problem, we compared the measured values of the actual base stations and the predicted values through the prediction model to compare the reliability. A method of constructing a real-time base station electromagnetic wave strength prediction evaluation system combined with software was also proposed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.77-83
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• 2001

We analyzed the mechanism of EM emission in telecommunication system and extracted the dominant parameter in EMC design. The I/O cable, ventilation hole and shield design of chassis are important EMC design Issues in telecommunication systems. Because telecommunication systems have much more I/O cables than other electronic products, EMC design of I/O cable is very important in telecommunication systems. Therefore by the method of experimentation and simulation, EM coupling mechanism of I/O cable was analyzed and the design rule for low emission was extracted. On the base of these EMC design rules, EMC design of telecommunication system was executed without complex redesign or debug. The result obtained by these methods was shown in this paper.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.351-356
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• 2009

A dual-mode annular ring antenna for both global positioning system(GPS) and satellite digital multimedia broad-casting(DMB) is designed. The proposed antenna consists of a coupling feed line and four slots on the annular ring patch. The gap between the feed line and the annular ring patch is used for an input impedance matching, and the slot length is used for adjusting the resonant frequency of the $TM_{21}$ mode at the DMB frequency. The antenna was fabricated and measured. The experimental results show that the antenna resonants at the GPS and DMB frequencies with suitable bandwidths, and had a broadside radiation pattern at the GPS band and a conical beam radiation pattern at the DMB band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.320-327
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• 2012

In this paper, a novel ultra wide band(UWB) antenna with tri-band notch capability is proposed. The proposed antenna can reject WiMAX(3.3~3.7 GHz), WLAN IEEE 802.11a/n(5.15~5.825 GHz), and ITU(8.025~8.4 GHz) bands. Band rejection capability is achieved only split ring resonators(SRRs) and complementary SRRs(CSRRs). The SRR under the radiating patch, the CSRR loaded on the radiating patch, and the CSRRs on the ground of the CPW feeding reject the WiMAX, WLAN, and ITU bands, respectively. The simulation and measurement results demonstrate the performances of the proposed antenna.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.222-229
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• 2007

Environmental tests should be carried out to show that design performance is in an operational condition in an actual operational environment to assure maintainability and reliability. Aero-products electromagnetic compatibility tests are performed mainly for the individual parts and Specifications MIL-STD-461E and RTCA DO-160E are developed for the military and commercial parts tests respectively. The MIL-STD-461E which is a military environmental test standard is targeting all munitions and that user can apply by selecting applicable requirements from this specification. On the other hand, requirements are applied exclusively for the Avionics Equipments in commercial test standard.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.6 s.109
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• pp.511-518
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• 2006

In this paper, a small RFID tag antenna in UHF band which has bandwidth-enhanced characteristic is proposed. The shape of the proposed antenna is a meander antenna to have size-reduced characteristic, and it consists of two radiators which make dual resonance in adjacent frequency to enhance bandwidth. By adjusting length and location of each radiator, the proposed antenna can make dual resonance at arbitrary location on the Smith chart, which is able to make impedance matching with RFID tag chip in wide frequency range. And it is apparent that the proposed antenna can have bandwidth-enhanced characteristic according to the simulated and measured results.