• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.7
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• pp.719-725
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• 2008

In this paper, we have proposed a printed monopole antenna using parasitic elements. The broadband characteristics of the antenna is obtained by using the printed monopole and parasitic elements. To confirm the broadband characteristics of the antenna, of have designed and fabricated the proposed antenna. The return loss and radiation patterns are measured in the frequency range of$0.8{\sim}1.2\;GHz$. The measured results show that the proposed antenna has return loss less than -10 dB in the operating frequency band and the radiation pattern is the dipole-like patterns. The antenna gain varies from 1.7 to 4.6 dBi in the operating frequency band. Thus, the proposed antenna can be used for the broadband repeater antenna $0.806{\sim}0.960\;GHz$(TRS-800, CDMA and GSM-900).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.2016-2021
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• 2009

In this paper, a dual-band antenna aimed for a mobile communication repeater was designed and measured. The operating frequency ranges are GSM(870${\sim}$960 MHz) and WCDMA(1920${\sim}$2170 MHz) bands. Experimental and numerical studies are performed for various design variables such as slot lengths. Using two meandering slots in the ground plane, we can obtain two higher resonant frequencies significantly with broader bandwidths. The measured maximum gain of antenna is 2 dBi in the GSM band and 2.45 dBi in the WCDMA band.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.365-379
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• 2008

In this paper we consider technological requirements of the on-channel repeater to broadcast the terrestrial digital multimedia broadcasting (T-DMB) signals using single frequency networks (SFN) and propose the configuration and implementation method of the equalization on-channel repeater (OCR) that meet such requirements. The proposed equalization OCR not only has short time delay, but shows high output power and good quality of output signal by removing a feedback signal due to incomplete antenna isolation and multipath signal existing between the main transmitter and the OCR. In addition, computer simulations and laboratory tests results are provided to figure out performance of the proposed equalization OCR.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.453-461
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• 2011

In order to use more efficiently limited frequency resources at the broadcasting band and to eliminate blanket area of the terrestrial broadcasting and to improve broadcasting quality. The importance of repeaters has increasing continuously. However, in case of T-DMB digital on channel repeater in OFDM systems, some of the signal radiated feedback again at the receiver antenna. So it generates feedback signal interference in repeater system. Also phase noise increases ICI(Inter Carrier Interference). It affects seriously the frequency domain equalizer. In this paper, we remove the feedback signal interference by LMS with correlation. Also we propose an effective equalizer algorithm that can remove ICI caused by phase noise and the power amplifier's back-off. In this simulation results, this system is satisfied the performance of BER=$10^{-4}$ at less than SNR=14 dB after compensation of phase noise.

• Journal of Broadcast Engineering
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• v.9 no.4 s.25
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• pp.371-383
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• 2004

In this paper we consider technological requirements to broadcast digital television signals using single frequency networks (SFN) in the Advanced Television Systems Committee (ATSC) transmission systems and propose equalization digital on-channel repeater (EDOCR) that overcomes the limitations of conventional digital on-channel repeaters (DOCRs). Since there are no forward error correction (FEC) decoder and encoder, the EDOCR does not have an ambiguity problem. In addition, since an adaptive equalizer in the EDOCR removes multi-path signals, additive white Gaussian noise (A WGN), and feedback signal due to low antenna isolation, the EDOCR may have good output signal quality with high power.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.552-559
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• 2011

In this paper, the frequency reconfigurable antenna is proposed and designed. The proposed antenna is designed using the vertically stacked dipole structures and have the operating band for Cellular, PCS/WCDMA/Wibro/WiFi and WiMAX. The operating frequency band is selected by three pair of PIN diodes using the voltage difference between each dipole antenna and feeding transmission lines. The proposed antenna meets the required operating bandwidth and the maximum gain for each frequency band are measured as 6.3 dBi, 5.4 dBi and 5.8 dBi, respectively. The proposed antenna in this paper can be applied for the future mobile small base station or repeater antenna because this antenna can provide the small size and high gain features.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1355-1362
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• 2000

Microstrip antennas are attractive for many applications because of their compact size, low profile, and light weight. Recently, the demand for the miniaturization of the personal communication equipment has been increasing along with the proliferation of personal communication systems. Thus, the development of small antenna has been highly demanded. In this paper, a new technique to reduce the overall dimension of a microstrip antenna with a locally non-homogeneous substrate configuration is proposed. The miniaturized microstrip antenna for a repeater system in a mobile communication cellular band(824~894 MHz) is designed with the proposed technique, and commercialized with low cost, light weight, and small size. Comparison between simulations, based on Agilent Technologies HFSS software, and measurements are provided. The proposed method will be more attractive for a light-weight, small-size, and low-cost microstrip array design. This paper also presents the bandwidth improvement technique for under-coupled microstrip patch antenna with a tuning stub.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.3-6
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• 2008

In this paper, we propose the folded PIFA with its made an alteration to a factor of resonance for L-slot PIFA. Proposed antenna maintain diminished size patch and improve each bandwidth of GSM(0.88$\sim$-0.96 GHz) and W-CDMA(1.92$\sim$2,17 GHz) for miniaturized repeater. The non-slot step folded PIFA's structure that design of essence was general L-slot PIFA for dual-band. It has no U-slot, multi band and the another slot. The parameters of proposed antenna were optimized for dual-band and compact size by folded singleness patch. Proposed antenna by using folded singleness patch take satisfaction main point, bandwidth of GSM and W-CDMA, compact patch size($39{\times}21{\times}13mm^3$). The antenna was designed by FDTD simulation tool and it was made from result of simulation. Measured data shown that the proposed non-slot step folded PIFA was strong possibility.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1095-1103
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• 2014

WBAN has received great attention recently due to its versatile applicability. In this paper, antennas suitable for WBAN communication depending on the locations of mobile devices and the manufacturing of a human equivalent phantom are introduced. The effect of the body on the communication performance is largely dependent on the locations of devices. Specifically, the radiation and return loss characteristics of the antenna are greatly influenced by the characteristics of a medium existing in the near-field of an antenna. Thus, the proper WBAN antenna design is important in establishing a successful communication link between the transceivers. To consider the effect of the body on the antenna performance, the human equivalent phantom is also important factor in the WBAN antenna design and measurement. In introduction, categorization of the WBAN communication channel is introduced and antenna characteristics required for each communication channel are described. In the main subject section, several WBAN antenna design examples along with the implementation of the human equivalent phantom are discussed. In conclusion, the factors, which have to be considered in the design process, and future research are mentioned.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.298-300
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• 2003

미국 PCS 대역 실내 간이 중계기에 사용될 수 있는 소형 안테나를 개발 제작하였다. 이동통신용 PCS 주파수는 CDMA에 비해 2배 정도 높기 때문에 건물 등 실내에서 통신하기에는 감쇠가 심하다. 따라서 건물 밖 신호를 받아서 건물의 특정부분으로 중계해주는 시스템이 필요하게 된다. 이 연구에서는 벽걸이 혹은 사진액자 형태의 중계기에 사용될 수 있는 소형이면서도 대역특성이 넓은 패치 안테나를 제작하였다. A4 크기의 중계기에 적용되는 소형 패치 안테나를 2개 배열하여 측정한 결과 S11의 -10㏈ 대역폭은 1.7 - 2.1㎓로 400㎒ 의 광대역이고, 이득 6 - 8.5㏈i 및 -l8㏈의 F/B 비 특성을 보였다.