• ETRI Journal
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• v.28 no.3
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• pp.383-385
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• 2006

A new meander-line antenna consisting of two open-ended strips is proposed for a compact and broadband UHF radio frequency identification tag. An equivalent circuit model for the proposed antenna is derived and used to perform a simple and wideband impedance match to an arbitrary complex impedance of a tag chip without any additional matching network. The performance of the proposed antenna is validated by comparing calculated and measured results, which show good agreement.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.31-31
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• 2009

In this paper, RFID antenna is designed and realized for UHF (860 ~ 960 MHz) application. Aluminium is used for patterning on polythelene terephalate (PET) substrate using etching process. The thickness of the substrates is 50 ${\mu}m$ and for copper and aluminium, the thickness is typically 18 ${\mu}m$ or 35 ${\mu}m$ and 10 ${\mu}m$ respectively. As a result of simulation, maximum return loss is indicated 0.04 dB at 960 MHz and 0.08 dB at 900 MHz.

• Proceedings of the KIEE Conference
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• 2003.10a
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• pp.207-210
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• 2003

가스절연개폐장치(Gas-Insulated Switchgear, GIS) 내부에서 발생하는 부분방전(Partial Discharge, PD) 신호는 1ns이하의 상승시간(rising time)을 가지므로, 이 신호를 효과적으로 측정하기 위해서는 초광대역(Ultra Wide Band, UWB)특성을 갖는 커플러가 필요하다. 본 논문에서는 이러한 UWB 특성을 구현하기 위해, 대수주기 톱니형 평면 안테나(log-periodic toothed planar antenna)와 등각 스파이럴 패치안테나(equi-angular spiral patch antenna)형태의 두 가지 초광대역 UHF 커플러를 설계 제작하였다. 제작한 커플러들의 특성을 파악하기 위해 안테나의 급전부에, 자체 설계한 매칭 회로인 발룬(balun, balance to unbalance)을 장착하여, 반사계수, 모의펄스에 의한 검출신호, 스펙트럼 둥을 측정하였다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.1
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• pp.101-106
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• 2004

The phenomenon of PD(Partial Discharge) is accompanied by electromagnetic wave which can be detected by UHF(Ultra High Frequency) antenna. The signals obtaining from UHF antenna are very high rapid pulse and have wide band frequency responses. The distribution of PRPD(Phase Resolved Partial Discharge) which consisted of those pulse train can show distinct characteristics of PD sources. But it is not sufficient to discriminate among PD sources. This paper suggests that the stochastic parameters formed by preprocessing of STFT(Short Time Fourier Transform) are good tools for differentiate from PD sources. The stochastic parameters are CC(Cross Correlation) mean value, CC standard deviation, CC skewness, CC kurtosis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.1
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• pp.6-16
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• 2009

For the application to the direction finding(DF) antenna for V/UHF bands, circular active array composed of 9 dipole element has been investigate. For miniaturization of the overall size array, the element has been chosen to be of the top-hat dipole type. For the broadband operation over 20-1300MHz, some number of pin diodes have been inserted in each arms of each dipole element. By employing this type of each element dipole, the effective dipole length can be increased or decreased according as the inserted pin diodes is on or off. The active array antenna has been design to be directly connected to the balanced push full amplifier such that the amplifier may play a role as a balloon and may improve the sensitivity as a receiver as well. The active array antenna has been designed and fabricated. Some experimental results have been presented in comparison with simulated results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1148-1157
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• 2013

In a passive UHF RFID system, the impedance matching between tag antenna and chip as well as the protocol parameter settings in a reader plays important role in determination of the maximum read-range. Almost no paper, however, has dealt with the above issues in relation with the maximum read range. In this paper, two known methods (of using the value from data sheets and proprietary RFID tester) and our proposing method in chip impedance evaluation are compared in terms of maximum read range. The read range of tags whose antenna impedance is conjugate matched with the chip impedance obtained from the proposed method is improved maximum 73 % more than that of tags from the other methods.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.12
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• pp.52-58
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• 2009

We propose a folded monopole antenna with loads, and analyze the roles of design parameters which affect the return loss of the proposed antenna. VSWR < 3 bandwidth of the antenna is 30 ~ 2000 MHz, ranging from the HF/VHF/UHF bands. For operating travelling antenna, we connect six loads at the end of the antenna. The reflected wave is drastically reduced due to the six loads. For improved return loss properties, we use Klopfenstein tape that determine positions and values of six loads. The propose antenna has omni-directional radiational patterns like that of conventional monopole antennas. For wideband impedance transformation, we use the balun which operating frequency region is 10 ~ 1900 MHz. We expect the proposed antenna has important role for the wideband and multi-rold multi-functional communication systems.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1638-1640
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• 2003

In the recent years, UHF PD measuring technique for detecting partial discharges was proved the effective method for Gas Insulated Switchgear (GIS). However, in case of GIS with a metal flange around insulating spacer, UHF PD measurement using typical external UHF PD sensor is difficult. In this paper, a novel hole-type UHF PD sensor based on Archimedean spiral antenna theory has been proposed and realized. All spacers with metal flange have small hole in order to inject epoxy. Using the novel hole-type UHF PD sensor, it makes detection possible to PD signal that are emitted through the epoxy injection hole. Additionally, the measuring characteristic of UHF PD signals from several artificial defects in GIS and the novel ${\Phi}$-f-q pattern analysis technology are discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.252-255
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• 2008

A study for discharge pattern analysis partial and fault location by use of UHF sensors in GIS. However, in the latter case, the results considered the velocity of EM waves modified by the waveguide characteristics of GIS bus bar were not reported yet. In this paper, UHF wide band sensor to detect partial discharge signals have been designed and manufactured to get the widest band characteristic by an application of Fat-Dipole UHF antenna and the result that the transmission velocity of EM waves is 2/3 of the light have been got through the consideration of waveguide characteristics. Also, to verify applicability on site of the developed method, self-designed external type UHF sensor have been installed on operating GIS in Korea Midland Power co. and detected location of the fault. Through the fault have been found at the location, the reliability of the developed method have been proved.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.177-179
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• 2005

본 논문에서는 지상파 UHF 휴대용 슬리브 안테나를 설계 제작하였다. 이 안테나는 차량 네비게이션장치에 들어가는 지상파 UHF TV 수신을 위한 안테나이다. 기존 모노폴 형태가 갖는 단점을 제거하고 성능 향상을 위해 세트 external 안테나로, 필요시에 목걸이형으로 부착이 가능한 구조를 가지고 있다. 동축선을 이용하여 슬리브 다이폴 안테나로 설계함으로써 안테나 입장에서 볼 때 접지가 부족한 문제를 해결하였다. 제작 측정한 결과 UHF 대역에서 VSWR 2:1 이하의 특성을 만족하였다.