• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2427-2433
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• 2015

A high-gain circularly-polarized patch antenna with a double-layered superstrate is proposed operating at a wireless LAN frequency. A superstrate has an array of metallic periodic unit cells and is located above the patch antenna with an air-gap. The designed antenna has a high gain of over 9.59dBi, which is the gain enhancement of 6.48dB compared to the patch antenna without superstrate. And it has a low axial ratio of under 3dB, so that it maintains the circular polarization of the patch antenna. The optimum air-gap height at the superstrate of $4{\times}4$ arrays is 25mm, which is equivalent to about $0.2{\lambda}$ at the frequency of 2.45GHz. We confirmed that the double-layered stacking of a superstrate increases the effective aperture size and hence it leads to enhance a gain of the patch antenna.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.874-879
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• 2016

A wideband stacked patch antenna with parasitic elements, rectangular and triangle shaped patches, is proposed. Two different shaped parasitic elements are placed in the above of main rectangular microstrip patch antenna in order to achieve wide bandwidth for 860 MHz band. Coupling between the main patch and parasitic patches is realized by thick air gap. The gap and locations of parasitic patches are found to be the main factor of the wideband impedance matching. The proposed antenna is designed and fabricated on a ground plane with small size of $119mm{\times}109mm$ for application of compact transceivers. The fabricated antenna on an FR4 substrate shows that the minimum measured return loss is below -11.68dB at 824 MHz and an impedance band of 818~919 MHz(11.7%) at 10dB return loss level. The measured radiation patterns are similar to those of a conventional patch antenna with maximum gain of 2.11 dBi at 824 MHz.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.1
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• pp.67-78
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• 2005

We proposed a blind watermarking for 3D mesh model using the patch CEGIs. The CEGI is the 3D orientation histogram with complex weight whose magnitude is the mesh area and phase is the normal distance of the mesh from the designated origin. In the proposed algorithm we divide the 3D mesh model into the number of patch that determined adaptively to the shape of model and calculate the patch CEGIs. Some cells for embedding the watermark are selected according to the rank of their magnitudes in each of patches after calculating the respective magnitude distributions of CEGI for each patches of a mesh model. Each of the watermark bit is embedded into cells with the same rank in these patch CEGI. Based on the patch center point and the rank table as watermark key, watermark extraction and realignment process are performed without the original mesh. In the rotated model, we perform the realignment process using Euler angle before the watermark extracting. The results of experiment verify that the proposed algorithm is imperceptible and robust against geometrical attacks of cropping, affine transformation and vertex randomization as well as topological attacks of remeshing and mesh simplification.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1063-1068
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• 2022

The modern society has become entry into the information age after the spread of Internet. In the information age, internet was developed from the wired access to the wireless Internet access. When a surge in demand for wireless Internet access, performance and speed of 2.4 and 5GHz band for Wi-Fi which leads to saturation of the communication was significantly fall. Accordingly, the communication of the 6GHz band for Wi-Fi 6E came to be interested. In this paper, we studied the design and fabrication of microstrip patch antenna to be used in wireless communication systems operating at around 6GHz band. To obtain antenna parameters such as patch size, inter patch space, antenna was simulated by HFSS(High Frequency Structure Simulator). From these parameters, slot microstrip patch antenna is fabricated using FR-4 of dielectric constant 4.4. The characteristics of fabricated patch type microstrip antenna were analyzed by network analyzer.

• Journal of Information Technology Services
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• v.13 no.1
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• pp.135-146
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• 2014

In this paper, an antenna has been proposed for the operation of mobile devices such as Zigbee. The presented rectenna operates at ISM (Industrial Scientific Medical) band of 2.45 GHz and consists of $2{\times}2$ array patch antenna and Villard voltage double rectifier circuit for high conversion efficiency. $2{\times}2$ array patch antenna is fabricated in FR4 substrate having thickness of 1.6mm and dielectric constant of 4.7. The proposed $2{\times}2$ array patch antenna resonates at 2.56GHz with return loss of 38.36dB, VSWR of 1.0244, and its impedance is matched to $50{\Omega}$. The fabricated rectenna has maximum conversion efficiency of 59.8% at an input power lever of 15dBm and load resistance of $500{\Omega}$.

• Journal of Biomedical Engineering Research
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• v.27 no.2
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• pp.64-72
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• 2006

The present study introduces a new cortical patch-based source model for EEG/MEG cortical source imaging to consider anatomical constraints more precisely. Conventional source models for EEG/MEG cortical source imaging have used coarse cortical surface mesh or sampled small number of vertices from fine surface mesh, and thus they failed to utilize full anatomical information which nowadays we can get with sub-millimeter modeling accuracy. Conventional ones placed a single dipolar source on each cortical patch and estimated its intensity by means of various inverse algorithms; whereas the suggested cortical patch-based model integrates whole cortical area to construct lead field matrix and estimates current density that is assumed to be constant in each cortical patch. We applied the proposed and conventional models to realistic EEG data and compared the results quantitatively. The quantitative comparisons showed that the proposed model can provide more precise spatial descriptions of neuronal source distribution.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.350-357
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• 2016

In this paper, a small mu-zero zeroth order resonance(ZOR) antenna based on meta structure is proposed using parasitic patch at 5.8 GHz. The mu-zero ZOR antenna is designed by utilizing the resonance of series inductance and capacitance of mu-negative transmission line and its size can be further reduced by a simple parasitic patch. The parasitic patch can increase series capacitance of mu-negative transmission line related to a resonant frequency. We have simulated and optimized dimension of the parasitic patch using Ansys commercial simulator(HFSS). As a result, the antenna has the following characteristics: kr of 0.59, efficiency of 92 %, and gain of 6.57 dBi. Also, its size is reduced by 24 % compared to a conventional mu-zero ZOR antenna. The measured results are in good agreement with the simulated results.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.155-158
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• 2004

This paper presents a CPW patch antenna with $\lambda/2$ CPW transmission lines. Through the full-wave simulation and the equations of gap capacitance, the dimensions of the CPW transmission lines and resonance circuit components are extracted. Using extracted dimensions, we designed and implemented CPW patch antennas in the range of frequency of 5GHz.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.432-435
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• 2007

In this paper, a dual band microstrip patch Antenna is designed for RFID Application. The antenna shows a good performance at the frequencies, 900MHz and 2.45GHz for the radiation characteristics and input impedance matching, as well. The reflection factor is lower than -25dB and a good directivity higher than 5dB is achieved for both frequency.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.145-148
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• 1998

In this paper, a microstrip antenna is designed using a rectangular patch. To find characteristics of the antenna, computer simulations of the rectangular single microstrip patch antenna are performed with changing width. And we compared the result of computer simulation with the experimental value. Through the results, we found that the 3-D FDTD method is an effective method for designing microstrip patch antenna. According to simulation the resonant point has been found it in the frequency received from GPS satellite. It is thought that make it match by adjusting the feedpoint.