• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4B
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• pp.388-396
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• 2002

In this paper, An aperture-coupled microstrip patch antenna operating at WLL frequency range(Rx : 2.3∼2.33Ghz, Tx : 2.37 ∼2.4Ghz) for WLL repeater is designed and fabricated. FR-4 epoxy substrate with 4.7 relative permittivity is inserted between feed-line and patch plane. Aperture-coupled structure is employed for consideration of bandwidth improvement and gain\`s characteristics. Air gap is arranged at each layer for bandwidth extension and radome is used as a protector in the upper patch. In this paper, both 1 port and 2 port are designed as 1$\times$2 array antenna which uses T-junction and λ$\_$g//4 transformer. Here, 1 port is used as transmitting/receiving antenna and 2 port is used as receiving antenna. Functionally independent two antennas using space diversity arrange slots between two antennas in order to be placed at the same place. As a result, we obtained a excellent isolation below -40dB and return loss is reduced by means of slots arrangement between patch and antenna.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.6
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• pp.37-45
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• 2016

The effect of substrate size on the radiation characteristics of an H-plane 5-elements linear array antenna with an aperture coupled microstrip patch antenna (ACMPA) as unit element is investigated. The distance between the patch center and the substrate edge on the E-plane ($d_E$) and that on the H-plane ($d_H$) at which the maximum broadside gain of an H-plane 5-elements linear array antenna occurs are the same to those of single ACMPA using a unit element. Besides, $d_E$ and $d_H$ at which the minimum broadside gain of an H-plane 5-elements linear array antenna occurs are almost the same to those of single ACMPA using a unit element. The edge effect on the radiation characteristics of an H-plane 5-elements linear array antenna is mainly determined by $d_E$. The optimum substrate size for the radiation characteristics of an H-plane linear array antenna could be obtained from that of single ACMPA using a unit element of an H-plane linear array antenna.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.6
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• pp.1015-1022
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• 2023

In this paper, we propose DLP(Dual Linear Polarization) antenna with aperture coupled feeding structure for private network. The proposed antenna has general aperture coupled structure and design two port between top and bottom layer to obtain the enhanced isolation. Also, The size of each substrate(top and bottom layer) is 34.0 mm(W)×34.0 mm(L), which is designed on the FR-4 substrate which thickness (h) is 1.0 mm, and the dielectric constant is 4.4. Also, the size of patch antenna is 12.70 mm(W2)×14.60 mm(L3), and it is located on the top layer. The size of feeding line is 24.0 mm(W2)×1.6 mm(L3), and is located at the bottom layer Also, rectangular slot is located on the ground plane between top layer and bottom layer. From the fabrication and measurement results, bandwidths of 300 MHz (4.52 to 4.82 GHz) for feeding port 1, and 170 MHz (4.65 to 4.82 GHz) for feeding port 2 are obtained on the basis of -10 dB return loss and transmission coefficient S21 is got under the -30 dB. Also, cross polarization isolation between each feeding port obtained

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.4
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• pp.357-365
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• 2009

A general analysis of a microstrip-to-vertically mounted slotline(VMS) coupler is presented with a view to developing an equivalent circuit, and the efficient evaluation of the related circuit element values. Based on this theory, the effects of frequency and structure parameters such as aperture length and VMS width on the characteristics of the coupler are studied. In order to check the validity of the proposed analysis and design theory, a C-band linearly tapered slot antenna fed by an aperture-coupled back-to-back microstripline-to- VMS coupling structure is optimally designed using a hybrid genetic algorithm. Moreover, the computed characteristics from the network analysis is compared to the measurement and simulation results. The obtained results fully validate the efficiency and accuracy of the proposed network model.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.20-23
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• 2018

In this work, an aperture-coupled patch array antenna with wideband characteristics was designed and arrayed in a $4{\times}1$ S-band. The designed antenna structure consists of two layers, and it possesses wideband characteristics achieved using coupling between the two layers. The first layer is comprised of four radiation patches and the second layer has an aperture and a ground plane. The antenna structure possesses 15 % wideband characteristics and the center frequency is at 3.2 GHz. A phase shifter was added to the array antenna to enable beam steering. The proposed phase array antenna was fabricated and measured. Our proposed design enables beam steering up to $35^{\circ}$.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.113-116
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• 2000

평행평판의 원면에 위치한 슬릿을 통하여, 슬릿의 바로 윗 부분에 도체 스트립이 있을 때 일어나는 전자기적 결합 현상에 대하여 살펴보았다. 슬릿의 폭이 파장에 비하여 매우 작을 때와 매우 클 때의 두 경우로 나누어서 기술하였다. 슬릿의 폭이 좁은 경우는 기존의 개구결합(aperture-coupled) 마이크로스트립 안테나에 해당되며 슬릿의 폭이 넓은 경우는 기존의 proximity-coupled 마이르로스트립 안테나에 해당된다. 본 연구의 결과는 기존의 마이크로스트립 안테나의 급전구조와 기존의 마이크로스트립 누설파 안테나의 급전구조 설계에 도움을 줄 것으로 생각된다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.369-373
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• 2000

This paper describes a design for microstrip EMC cross dipole array antenna with circular polarization. To realize the wide bandwidth and circular polarization, the electromagnetic-coupled cross dipole is used. To obtain the uniform aperture illumination, offset technique for array is adopted. In 20-element array design, the calculated axial ratio and gain are about 0.1 dB and 9.9 dBi at 12GHz, respectively. The frequency characteristics of a fabricated 20-element array antenna are measured. The calculated results agree well with the measured ones.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.199-207
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• 2021

This paper deals with accurate image reconstruction of gamma camera using a coded-aperture mask based on pixel-type CsI(Tl) scintillator coupled with silicon photomultipliers (SiPMs) array. Coded-aperture imaging (CAI) system typically has a smaller effective viewing angle than Compton camera. Thus, if the position of the gamma source to be searched is out of the fully-coded field-of-view (FCFOV) region of the CAI system, artifacts can be generated when the image is reconstructed by using the conventional cross-correlation (CC) method. In this work, we propose an effective method for more accurate reconstruction in CAI considering the source distribution of partially-coded field-of-view (PCFOV) in the reconstruction in attempt to overcome this drawback. We employed an iterative algorithm based on compressed-sensing (CS) and compared the reconstruction quality with that of the CC algorithm. Both algorithms were implemented and performed a systematic Monte Carlo simulation to demonstrate the possiblilty of the proposed method. The reconstructed image qualities were quantitatively evaluated in sense of the root mean square error (RMSE) and the peak signal-to-noise ratio (PSNR). Our simulation results indicate that the proposed method provides more accurate location information of the simulated gamma source than the CC-based method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.4
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• pp.342-350
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• 2002

In this paper, aperture coupled U-slot microstrip antenna with wideband stub is investigated. The dielectric constant of the substrate is 2.2 and the hight of the substrate is 62 mil. The impedance bandwidth (VSWR<1.5) of U-slot antenna with wideband stub is about 10 %. The bandwidth characteristic of U-slot antenna wish wideband stub is compared with that of antenna without it. And the results of parameter studies of the wideband stub provides the optimum characteristics of bandwidth and matching.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.757-765
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• 1999

In this paper, L-Type aperture coupled circular polarization patch antenna for mobile communication(IMT-2000, 1.9375 GHz), which is capable of being mounted in mobile unit, was designed and fabricated. This antenna is expanded to the $2\times2$ circular polarization array antenna for satellite mobile communications which are using the L-band frequency. The results are as followings : Returnloss 18.56 dB, beamwidth $60^{\circ}$, gain 7 dBd, axial ratio 0.9 dB in the case of single element and returnloss 28.43 dB, beamwidth $38^{\circ}$, gain 9.8dBd, axial ratio 1.5 dB in the case of $2\times2$ array, respectively.