• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.4
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• pp.354-362
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• 1997

In this paper, a microstrip antenna with a small loop consisting of the left and right parallel plate to load a capacitor is proposed. It is obtained the improved high gain and bandwidth than the antenna consisting of the right parallel plate to load a capacitor on QMSA (Quarter-Wavelength Mi- crostrip Antenna). Also, the designed and manufactured antenna can receive both vertically and horizontally polarised waves to operating frequency of 1.5 GHz; therefore this is available as a small antenna for wireless telephones and will be quite useful for indoor communication.

• Journal of Navigation and Port Research
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• v.35 no.7
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• pp.563-568
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• 2011

The various properties such as the electric current distribution, resonant frequency and radiation patterns of open-ended meander slot antenna placed on a small ground plane, are investigated to give the help in performing antenna design. Based upon these characteristics, the designed antenna which is only 22mm($0.06{\lambda}_g$) in height and 31mm($0.09{\lambda}_g$) in width can operate at the 433 MHz with the measured radiation efficiency of 8% and end-fire radiation pattern. These properties make the antenna suitable for the handheld device such as the wireless remote controller.

• ETRI Journal
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• v.30 no.4
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• pp.597-599
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• 2008

This letter presents the design of a small and low-profile RFID tag antenna in the UHF band that can be mounted on metallic objects. The designed tag antenna, which uses a ceramic material as a substrate, consists of a radiating patch and a microstrip line with two shorting pins for a proximity-coupled feeding structure. Using this structure, impedance matching can be simply obtained between the antenna and tag chip without a matching network. The fractional impedance bandwidth for $S_{11}$ <3 dB and radiation efficiency are about 1.4% and 56% at 911 MHz, respectively. The read range is approximately from 5 m to 6 m when the tag antenna is mounted on a metallic surface.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.6
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• pp.52-58
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• 2008

In this paper, electrically small square loop antenna with SRR (Split Ring Resonator) cover structure is built and tested. The proposed antenna has very small size, ka = 0.34 by Chu limit. The experimental result shows that the resonant frequency and impedance bandwidth($VSWR{\leq}2$) are 906MHz and 5.8MHz (901.7 - 907.5MHz), respectively. The proposed antenna is matched and designed by equivalent circuit model. The proposed antenna is fabricated simple structure without additional matching network and printed on a Teflon substrate without ground plane. Therefore, it has advantages of low cost, small size, and light weight and will be applied to wireless communication systems where small antennas are required.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.311-318
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• 2018

In this paper, test-bed for the evaluation of wireless communication system on a small launch vehicle is proposed. The proposed test-bed consists of antenna test-coupler, RF attenuators, and RF switch modules. The antenna test-coupler isolates antennas for each band and transmits / receives wireless signals. The RF attenuator and switch are used for path selection of testing signal path. In design and measurement result of the antenna test-coupler, the antenna test-coupler has shielding effect higher than 39.3, 47.1, 56.1 dB at UHF-, S-, X-band. Through testing on small launch vehicle wireless communication system, we were able to successfully transmit and receive data between each test system and launch vehicle with antenna path switching.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.4
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• pp.28-34
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• 1975

텔레비젼 수신용 안테나로써 가장 널리 사용되고있는 Yagi안테나는 구조가 간단하고 지향성 이득등이 좋으나 방사주파수에 대한 반파장길이의 소자를 사용하므로 칫수가 커지고 주파수대역이 좁다. 따라서 설치 취급등에 불편을 느낄 경우가 많다. 한편 최근 일반적으로 아무곳에서나 용이하계 설치할 수 있을만큼 소형이면서 화질이 좋은 수상이 가능한 수신안테나에 대한 요망이 커지고 있는데 본 연구에서는 그 파장에 비해서 소형인 폴디드·다이폴 안테나 소자 2개를 좁은 간격으로 배열하고 이들을 이상결합하므로써 VHF텔레비젼전파의 고채널 주파수대에서 비교적 양한 단일지향성을 얻고 있다. 본 안테나에 능동소자를 이용한 저잡음광대역증폭기를 삽입한다면 다소자 Yagi안테나에 비나될 전후방비를 갖는위에 그의 이득도 크게 증가되어 일반수상안테나로 뿐만 아니라 고우스트 방지용실내안테나로서 상당한 기여틀 할것으로 생각된다. The Yagi antenna, which is most widely used for television receiving, has simple form and good directiyity as well as high gain, but it must be made with linear elements of half wave length. Therefore, the dimension of multi-element Yagi antenna becomes bulky and so a(ten it is inconvenient to install and handle, because of its big size. Moreover the frequency band width of the Yagi antenna is usually not broad enough to cover the total frequency range of VHF TV channels in our country. Recently, the aemand for an antenna which is not only small enough to install it easily anywhere but also assures good quality of pictures is generally increasing. In this study 2 elements o( folded dipole, which is small compared to its electrical ways length, are fixed parallel to each other with a narrow distance and the emfs induced in them are made to get together with some phase difference. This new phased array antenna has shown a relatively good unidirectivity through over the high channel VHF television frequency hand as well as the good PIB ratio which is comparable to that of multielements Yagi antenna. As a result this new antenna will be used as a VHF high channel TV receiving antenna and it may become better antighost antenna when used inside the room than other room antennas.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.2
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• pp.217-226
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• 2001

A small sized ceramic dielectric patch antenna is designed and implemented for GPS/GLONASS combined receiver, and it shows a wideband characteristics with circular polarization. For the miniaturization of the antenna, high-permittivity dielectric material is used, and the wideband characteristics with low axial-ratio is achieved by using dual feed with 90$^{\circ}$ phase difference. The measured data of the manufactured antenna show that the bandwidth is 242 MHz, the axial ratio is less than 3 dB, the half-power beam-width is more than 112$^{\circ}$, and the antenna satisfies the required characteristics of the GPS/GLONASS antenna.

• Journal of the Korea Society of Computer and Information
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• v.9 no.4 s.32
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• pp.93-97
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• 2004

This paper proposed that a small type conductor surface open-loop antenna model for the moisture sensor and its operating characteristics were analysed numerically by using the moment methods. The numerical analysis results from this antenna model showed that this antenna could match the input impedance to $50[{\Omega}]$ by changing parameters of the antenna in the frequency range from 300[MHz] to 500[MHz]. This model also showed that the open-loop radius. height and wire width give a tremendous influence on the antenna resonance variation. while the loaded inductance values affects the variation or the input impedance at the resonance frequencies.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.351-355
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• 2003

In this paper, rectangular patch antenna is miniaturized by changing the middle of patch into narrow microstrip line except the edges of the patch where the fringing field occurs. Miniaturized rate, gain, bandwidth, radiation pattern of suggested antennas were compared with general square and rectangular microstrip antennas by using simulator Ensemble. As a result, it reduces the dimension of antenna by 44 % and improves the characteristic of x-pol by 40 dB as an advantage when compare with square microstrip antenna while it reduces bandwidth.

• Journal of electromagnetic engineering and science
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• v.6 no.3
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• pp.165-170
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• 2006

In this paper, magneto-dielectric material is proposed to use for minimizing antenna size. One examle of very small antenna is presented to prove this with antenna's area of $0.078\lambda_0\times0.016\lambda_0$, and just moderate values of permittivity and permeability while the return loss can reach - 38 dB at the resonant frequency. The parameters of dielectric material for that best performance are $\varepsilon_r=1.71-j0.004$, and $\mu_r=2.39-j2.58$. Besides, this material also has ability to control the trade-off between the gain and bandwidth while keeping the antenna size unchanged.