• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.505-513
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• 2000

This study suggests new antenna design for polarization diversity. For dual polarization, two port feeding lines are printed on two separate layers and cross-shaped aperture is located on ground between the substrates. For reducing back radiation, a reflector is attached around $\lambda$/4 behind feeding substrates. For wide bandwidth we use a perturbed patch with saw tooth shaped. This perturbation effect causes reduction of antenna size and also reduction of array size. With the antenna proposed here, $1\times4$ array dual polarization antenna for polarization diversity of PCS base station is built. One single element has as large as 10.3%, 11.3% bandwidths at each port, V.S.W.R less than 1.3 and the isolation is less than -40 dB, also array antenna has 13.2% 12.7% band bandwidth, V.S.W.R less than 1.3 the isolation below -36dB and the XPD of 10 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.363-644
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• 1997

This paper presents the design and fabrication of a shaped-beam array antenna which will be used for a PCS basestation using structure that is coupled to a microstrip line by an aperture on the interening ground plane. The shaped-beam pattern is obtained by an antenna synthesis method. An array antenna considering the mutual coupling between array elements patches) and a feeding network are designed by CAD tools. The feeding network is designed by using the Wilkinson power divider to obtain the optimized shaped-beam. The designed results are compared with the measured data.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.919-930
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• 2001

This paper presents a wideband technique of impedance and axial-ratio bandwidth which uses the stacked planar array structure through optimum design of sub-polarization generating sections and parasitic patch. So, the effect of the dual-resonance characteristic can contribute to the bandwidth expansion of single fed planar array antenna using circular polarization which doesn\`t hire previous bandwidth expansion technique. The antenna can be used as a dual-band antenna by adjusting the resonance frequencies as well, and then the antenna is designed and fabricated in the frequency band of domestic satellite-TV service. This antenna has the performance of 9.7 % impedance bandwidth and 24 dBi of antenna gain. And it has also 2.8 % and 1.4 % of 3 dB Axial-ratio bandwidth at 11.4 GHz and 11.8 GHz respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.268-272
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• 2002

슬롯이 있는 직사각형 마이크로스트립 안테나의 이중주파수 동작 특성을 연구하였다. 마이크로스트립 안테나의 급전방식은 전자기적으로 결합된 단일 마이크로스트립 안테나이며, 패치구조는 직사각형 패치의 대각선 방향에 "ㄱ"형 슬롯을 대칭으로 배치시켰다. 본 논문에서 제안된 "ㄱ"형 슬롯의 장점으로는 패치의 크기를 줄이는 효과와 동시에 이중 대역의 주파수를 갖는 것으로 확인되었다. 제안된 마이크로스트립 안테나의 반사손실은 S11에서 -10 dB 기준으로 첫 번째 공진점 4.808 ㎓ 에서는 120 MHz의 대역폭을 가졌고, 두 번째 공진점 6.175 GHz 에서는 100 MHz의 대역폭을 가졌다.는 100 MHz의 대역폭을 가졌다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.11A
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• pp.912-920
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• 2003

This paper is about the design of a small wide-band slot loop antenna, which consists of dual offset-fed and rectangular loop within the slot on a substrate. The proposed antenna is a novel structure generating a multi-resonances due to three geometrical resonance structures. The impedance matching of this antenna can be accomplished by changing the offset position of dual-fed at resonance frequencies. In this experiment, the slot of a fabricated antenna has a center frequency of 6.755㎓, 12.5mm${\times}$50mm in size and the rectangular loop has 10.5mm${\times}$27.5mm in size. The measured result is fractional bandwidth 63.21% with VSWR 2:1, which is agreed with the simulated result within 5% of error, and the maximum antenna gain is 7.42㏈i.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.2
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• pp.291-298
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• 2018

In this paper, we propose an antenna that improves narrow band characteristics which is a disadvantage of inverted-F type antenna and utilizes the structural advantages of small size and low profile by modifying the inverted-F type antenna structure and applying CPW feeding method. Experimental results show that the broadband characteristic of about 40% at the center frequency of 3 GHz is seen, and it is found that the narrow band characteristic which is a disadvantage of the conventional inverted F antenna can be improved. The radiation pattern showed almost omnidirectional characteristics and the maximum gain was about 2.0dBi.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.662-668
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• 2009

Design of IPI(Inverted PI) feeding internal antenna for the gain improvement of mobile phone was proposed. IPI feeding structure affects on both low radiation resistance of antenna and increase current for the internal antenna such as IFA(Inverted F Antenna). By these facts, antenna fed by IPI can get the gain improvement with increasing radiation efficiency. For the verification, we applied IPI feeding structure to conventional quad band IFA. Measurement shows that IPI-IFA has 0.3~2.0[dB] higher gain than conventional IFA on GSM/DCS/USPCS/WCDMA band.

• Journal of IKEEE
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• v.26 no.1
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• pp.137-140
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• 2022

In this paper, we proposed a new W-band monopulse tracking system based on reflectarray antenna structure. The proposed reflectarray antenna monopulse tracking system consists of four feed horn antennas and a planar reflector using a microstrip reflectarray. The four feed horn antennas have a gain of 10 dBi and a half-power beam-width of 56 degrees symmetrically in the E/H plane. It was confirmed that the reflectarray antenna using one feed horn antenna has a size of 41.8 × 41.8 mm², a gain of 26.8 dBi, and a half-power beam-width of about 5.6 degrees. The reflectarray monopulse tracking system using 4 feeding horn antennas is well matched from 75 GHz to 90 GHz, and the isolation is secured by more than 10 dB. Finally, the proposed system shows the tracking range of 5.98 degrees and the tracking error range was 0.02 degrees.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1030-1036
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• 2010

This paper proposes a simulation design for feeding probe with the CMM(Cylindrical Magneto Material) structure for broad bandwidth of a dipole type antenna. In order to ensure low frequency bandwidth, the magnetic material with high relative permeability was considered in design calculation. It was confirmed that the broad bandwidth was independent on the relative permeability value and depended on the control of distance($r_m$) between magnetic material and feeding probe, and of magnetic material thickness($t_m$). Furthermore, an antenna size with the CMM was miniaturized about 18 % comparison with its size without the CMM.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.927-932
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• 2008

We propose a novel $4{\times}4$ Hadamard matrix feed network for a $4{\times}1$ array antenna to form a dual beam. If each element of the array is excited following the elements in a row of the Hadamard matrix, a two-lobed antenna beam can be obtained. The angle between the two lobes can be controlled. The Hadamard matrix feed network consists of four $90^{\circ}$ hybrids, a crossover and four $90^{\circ}$ phase shifters. The array, including the Hadamard matrix feed network, was fabricated on a microstip structure. The measured beam directions of the two lobes are $0^{\circ}$, ${\pm}15^{\circ}$, ${\pm}33^{\circ}$, ${\pm}45^{\circ}$ depending on the choice of the input port of the feed network.