• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.33-44
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• 2000

The lightning with high voltage and current can enter the basestations for mobile communication through their antenna. The device which can protect the basestation against the lightning, is surge arrestor. In this paper, the concept, kind, operating mechanism, design and fabrication of surge arrestor were studied. Based on the studied data, variable surge arrestors were designed for the current mobile communication service like a cellular, GSM and PCS and the next generation mobile communication like a IMT-2000. Computer simulation for the prediction of their characteristics and inner structure optimization for the improvement of their electrical characteristics were carried with high frequency 3D structure simulator. Quarter wave short stub surge arrestors for IMT-2000 were fabricated with their final design and then the measurement of electrical characteristics and the lightning test were executed. As a results of measurement, we obtained below 1.05 of VSWR, -0.035 dB of insertion loss, -150 dBc of intermodulation and 7∼ll V of residual voltage.

• The Magazine of the IEIE
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• v.22 no.9
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• pp.42-52
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• 1995

최근 연구개발 및 표준화에 박차를 가하고 있는 Personal communication systems(PCS)의 개요 및 개발동향을 살펴보고 앞으로의 PCS 전개방향을 전망한다. 현재 여러 형태의 PCS 시스템들이 연구개발 중이며 특정기술에 의존하는 경향을 보이고 있다. 그러나 다가올 2000년대에는 이를 통합하는 표준으로서 유럽지역의 UMTS(Universal Mobile Telecommunications System)와 국제적 규모의 차세대 공중육상이롱통신 시스템인 FPLMTS/IMT-2000(Future Public Land Mobile Telecommunications System/lnternational Mobile Telecommunlcation-2000)이 확립될 것으로 보이며, 최종에는 이를 통합하는 하나의 국제표준이 형성될 것으로 본다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.99-104
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• 2003

We are designed and fabricated the Printed dual monopole antenna with CPW feeder for PCS and IMT2000 band. In this paper il proposed modified dual monopole antenna that is transform conventional monopole antenna to get dual band frequency. The dual monopole antennas had broad bandwidth and omni -directional radiation patterns in construct with conventional monopole antenna. On a monopole operated a stub to other monopole antenna, we could obtain easy an impedance matching. It is increased band width of impedance. The antenna bandwidth is about 150MHz(1.74 ∼1.89〔GHz〕)at 1$^{st}$ resonance frequency and 290MHz(1.95∼2.24GHz) at 2$^{nd}$ resonance frequency on VSWR(equation omitted)1.5 and then we can be got not only 1.75∼1.87〔GHz〕 PCS band but also 1.92∼2.17 〔GHz〕).GHz〕).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.12-20
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• 2004

In this paper, the detection of 1 g and 10 g averaged SAR on human head caused by PCS/IMT-2000 handhold phones is analyzed and discussed. Planar structured Single-Semi-disc MPA and double-Semi-disc MPA is designed and resonance characteristics with variety of design parameters are analyzed. As a result, 2.0 ㎓ center frequency, at the bandwidth of single-semi-disc MPA and double-semi-disc MPA are 15.5 ％ and 31 ％, respectively. And monopole antenna with W4 length is designed and compared with double-semi-disc MPA in SARs. The SARs caused by double-semi-disc MPA on folder type handset are 0.811 W/kg and 0.507 W/kg and are about 32.7 ％ lower than monopole-1.206 W/kg and 0.7552 W/kg. While the radiation pattern of the monopole antenna is symmetrical, that of planar structured antenna is asymmetrical and SAR caused by double-semi-disc MPA is less than SAR by the monopole antenna.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.2-11
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• 2001

The L-shaped strip is shown to be an attractive feed for the thick mierostrip antenna (thickness around 10% of the operating wavelength). The L-strip incorporated with the radiating patch introduces a capacitance suppressing some of the inductance introduced by the strip itself. In this paper, a wideband microstrip patch antenna fed by L-strip for the PCS ($1,750{\sim}1,850MHz$) and IMT-2000 ($1,920{\sim}2,170MHz$) broad-band is presented. A two-element array fed by L-strip is also proposed. Both the antennas have stable radiation patterns across the passband. The impedance bandwidth is over 31% (VSWR < 1.5, 615 MHz) of the center frequency. Moreover, both the antennas have about 7 dBi average gain.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.5
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• pp.827-836
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• 2001

The L-shaped strip is shown to be an attractive feed for the thick microstrip antenna (thickness around 10% of the operating wavelength). The L-strip incorporated with the radiating patch introduces a capacitance suppressing some of the inductance introduced by the strip itself. In this paper, a wideband microstrip patch antenna fed by L-strip for the PCS (1,750~1,850 MHz) and IMT-2000 (1,920~2,170 MHz) broad-band is presented. A two-element array fed by L-strip is also proposed. Both the antennas have stable radiation patterns across the passband. The impedance bandwidth is over 31% (VSWR < 1.5, 615 MHz) of the center frequency. Moreover, both the antennas have about 7 dBi average gain.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7B
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• pp.727-736
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• 2002

In this paper, the broadband microstrip antenna with small size, thin-profile, conformability and ease of manufacture is proposed for providing PCS(down link: 1.75GHz∼1.78GHz, up link: 1.84GHz∼1.87GHz) '||'&'||' IMT-2000(down link: 1.92GHz∼1.98GHz, up link: 2.11GHz∼2.17GHz) services simultaneously. By using double U-slots and matching stub, the bandwidth and operating performance of printed antenna was significantly improved, with need for a complex fabrication procedure. We have also studied the various parameters of the U-slot$_2$for the performances of the antenna. Impedance bandwidth of the wideband microstrip antenna with the double U-slots is about 30.45% (VSWR<2)

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.75-79
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• 2004

In this paper, a single plane wide band microstrip antenna for integrated circuit as MMIC and LTCC is designed and fabricated. A new configuration for a wide band microstrip antenna with omni-directional pattern is proposed. This antenna consists of two rectangular folded dipoles, which are fed by a coplanar waveguide(CPW). It was effected stabilization ground that a signal plane of CPW feed have been limited ground plane. Therefore, a ground plane of folded structure should be extended outside folded antenna in this research. The characteristics of the proposed antenna were analyzed by using an FDTD methods. The return loss and radiation patterns were simulated and measured. The proposed antenna is get 120MHz bandwidth of PCS band and 250MHz bandwidth of IMT2000 band, used ISM band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.4 s.95
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• pp.359-365
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• 2005

This paper designed a very low profle, light and broadband internal antenna for operating at PCS, IMT-2000 and Wibro bands. The proposed antenna can be reduced the size by using shorting-pin and a broadband characteristic is obtained by using slit. It is optimized by using the CST Microwave Studio commercial software based on the FIA(Finite Integration Algorithm) and PBA(Perfect Boundary Approximation) and then fabricated and measured. As a result of measurement, the bandwidth(VSWR<2.5) is $40.8\;\%$ at $1.934\;\cal{GHz}$ and the size of antenna is 3$30\;\cal{mm}\times10\;\cal{mm}\times0.2\;\cal{mm}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.11 s.114
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• pp.1096-1104
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• 2006

In this paper, the broadband antenna for the combined base station of Cellular/PCS/IMT-2000/Wibro and S-DMB services is designed and the proposed antenna allows having sufficient coverage for each service band. In order to get the broadband impedance matching, the tapered sections are applied on the both terminus of hi-conical respectively. The design parameter is calculated and simulated by using FDTD method. As a result, the measured bandwidth of the proposed antenna is $0.79GHz{\sim}2.93GHz$ and the gain is distributed from 5.5 dBi up to 8.19 dBi.