• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.649-652
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• 2007

In the world each bureau tries an introduction of Mobile WiMAX frequency in the various band. Particularly, 2.5 GHz band is likely to be used as the future mobile telecommunication using as the IMT-2000 additional band which determined in WRC, and it comes into the spotlight as the band of the global radio broadband service including the Mobile WiMAX. Thus, the activity for including the Mobile WiMAX to the IMT-2000 technical standard is unfolded for the WiBro market development in the ITU-R WP8F conference, and the adoption or rejection will be finally determined in the ITU-R RA-07. Therefore, this paper tried to look for the plan for reaction according to the IMT-2000 standard acceptance of WiBro technology and the foreign usage plan of 2.5 GHZ band.

• Publications of The Korean Astronomical Society
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• v.18 no.1
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• pp.97-110
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• 2003

WRC-03 was held between 9 June and 4 July 2003 in Geneva, Switzerland. Over 2,200 delegates from 138 ITU Member States attended the Conference. The delegates considered some 2,500 proposals, and over 900 numbered documents related to 50 agenda items. The final output of the Conference consists of 527 pages of new and revised text of the Radio Regulations. This paper provides some details about the outcome of the radio astronomy related issues at the WRC-03 Conference. It is divided into two part: a) Agenda item1.8.2 and b) Agenda item 1.32, related to radio astronomy. Relevant extracts from the Final Acts of WRC-03 are given in the Appendix. Agenda item 1.8.2 was one of the most controversial Agenda Items at WRC-03. Studies were carried out within ITU-R TG 1/7 for the last three years; the results of these studies are summarized in Recommendation ITU-R SM.1633. The Conference adopted a new footnote (5.347A), that calls for the application of Resolution 739 (WRC-03) in the 1452-1492 MHz, 1525-1559 MHz, 1613.8-1626.5 MHz, 2655-2670 MHz, 2670-2690 MHz and 21.4-22.0 GHz bands. Agenda item 1.32 is to consider technical and reglatory provisions concerning the band 37.5-43.5 GHz, in accordance with Resolutions 128 (Rev.WRC-2000) and 84 (WRC-2000). WRC-03 reviewed and adjusted the New footnotes 5.551H and 5.551I cover the protection of radio astronomy observations in the 42.5-43.5 GHz band from unwanted emissions by non-geostationary (5.551H) and geostationary (5.551I) FSS and BSS systems, respectively.

• Journal of the Institute of Convergence Signal Processing
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• v.3 no.2
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• pp.45-52
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• 2002

EMI(Electromagnetic Interface) is a measure of electomagnetic radiation from equipment in the range of 10KHz to 3GHz, and can cause unexpected reactions of electronics/electrical equipment. In this study, for safe and stable communication operation, a STGU(System Timing Genetation Unit), which is a 2.5Gbps SDH System and a major EMI source, was employed to simulate electromagnetic interface. In On-Site test, the power of fundamental frequency of EMI of interest and its harmonics were measured. Also, a low pass filter at cut-off frequency of 2GHz was specifically designed to minimize the effect of EMI between electronic components. When the low pass filter was implemented within the STGU, the power of EMI decreased more than 20dBm. Finally, when TIE and MTIE, two important quality measure in synchronous reference clcok, was assessed, ITU-T G8l3 requirements are satisfied.

• Journal of Satellite, Information and Communications
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• v.1 no.2
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• pp.8-15
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• 2006

Under Resolution 122 (Rev. WRC-03), ITU-R is invited to study, as a matter of urgency, power limitations applicable for HAPS ground stations to facilitate sharing with space station receivers in the bands 47.2-47.5 GHz and 47.9-48.2 GHz. However, there have been no studies on this issue. Recommendation ITU-R SF.1481-1 which was developed during past study period, provides methodology and system characteristics for analyzing the sharing feasibility between systems in the FS using HAPS and systems in the FSS. System characteristics for a typical HAPS in the bands above are also given in Recommendation ITU-R F.1500. This paper provides the results on power limitations applicable for HAPS ground stations in accordance with Resolution 122 (Rev. WRC-03). As already shown in ITU-R Recommendation the results show that a sufficient separation distance is required for sharing between HAPS ground stations and FSS satellite systems. We obtain some examples of the sharing conditions considering reducing the power level of HAPS ground stations and using the antenna beam pattern with the low sidelobe to decrease the interference level affecting FSS satellite receiver.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.8
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• pp.763-771
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• 2013

In this paper, the propagation characteristics for ISM(Industrial Scientific and Medical) and TVWS(TV White Space) in indoor building environment are analyzed in comparison with theoretical and experimental results, the excellent propagation characteristics of the TVWS is confirmed. To this end, signals which have center frequencies of 503 MHz and 2.4 GHz are generated in building propagation environment. Through that, received power strength is measured according to the location and measured path loss is analyzed. Theoretical path loss is calculated using Hata, Extended Hata, Extended Hata SRD, ITU-R P.1238 and reliability for channel model in indoor environment is analyzed.

• Journal of electromagnetic engineering and science
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• v.14 no.1
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• pp.31-35
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• 2014

An ultra-wideband (UWB) circular monopole antenna with a multiband-notched characteristic is proposed. The multiband-notched filter consists of three different sized folded slots, which are distinctly assigned for the notched band at the 3.5-GHz WiMAX, 5-GHz WLAN, and 8-GHz ITU bands. The proposed antenna results in a measured ${\mid}S_{11}{\mid}$ < -10 dB, which completely covers the UWB band (3.1 10.6 GHz) with three notched bands at 3.5, 5.5, and 8.0 GHz. The antenna yields an omnidirectional radiation pattern and high radiation efficiency.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.35-43
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• 2016

A compact ultra-wide band antenna with a quadruple band-notched characteristic is proposed. The proposed antenna consists of a slotted trapezoid patch radiator, an inverted U-shaped band stop filter, a pair of C-shaped band stop filters, and a rectangular ground plane. To realize the quadruple notch-band characteristic, a U-shaped slot, a complementary split ring resonator, an inverted U-shaped band stop filter, and two C-shaped band stop filters are utilized in this antenna. The antenna satisfies the -10 dB reflection coefficient bandwidth requirement in the frequency band of 2.88-12.67 GHz, with a band-rejection characteristic in the WiMAX (3.43-3.85 GHz), WLAN (5.26-6.01 GHz), X-band satellite communication (7.05-7.68 GHz), and ITU 8 GHz (8.08-8.87 GHz) signal bands. In addition, the proposed antenna has a compact volume of $30mm{\times}33.5mm{\times}0.8mm$ while maintaining omnidirectional patterns in the H-plane. The experimental and simulated results of the proposed antenna are shown to be in good agreement.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.11
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• pp.1078-1091
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• 2011

In this paper, a triple band-notched UWB antennas using a spiral resonator and a complementary split ring resonator is proposed as two types. The band-rejection characteristic of the designed antenna is analyzed through the structure and equivalent circuit model of spiral resonator and CSRR. The measured results of first type antenna show that a VSWR less than 2 was satisfied with a resonant frequency in the range of 1.16~12 GHz and it can be obtained the band-stop performance at 3.3~3.85 GHz, 5.15~6.1 GHz, and 8.025~8.5 GHz. The measured results of second type antenna show that a VSWR less than 2 was satisfied with this antenna works from 1.79 to 12 GHz and it can be achieved the band-notched performance at 3.3~3.88 GHz, 5.12~5.94 GHz, and 8.025~8.51 GHz. Through the measured results, the designed antenna was satisfied UWB band except for triple notched bands.

• Photonics industry news
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• s.17
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• pp.10-19
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• 2003

We have developed a single integrated wavelengh selection type - 8channel light source module. This module oscillates in 8 wavelengh at 200GHz(1.6nm) ITU channel intervals within the c-band (1530~1560nm), and can transmit at 1.25Gbps level.