• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.142-147
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• 2023

This paper presents a novel design of a differential patch antenna for 60-GHz millimeter-wave applications. The design process of the back-to-back (BTB) patch antenna is based on the conventional single-patch antenna. The initial design of the BTB patch antenna (Type-I) has a patch size of 0.66 × 0.98 mm² and a substrate size of 0.99 × 1.48 mm². It has a gain of 1.83 dBi and an efficiency of 94.4% with an omni-directional radiation pattern. A 0.4 mm-thick high-resistivity silicon (HRS) is employed for the substrate of the BTB patch antenna. The proposed antenna is further analyzed to investigate the effect of substrate size and resistivity. As the substrate resistivity decreases, the gain and efficiency degrade due to the substrate loss. As the substrate (HRS) size decreases approaching the patch size, the resonant frequency increases with a higher gain and efficiency. The BTB patch antenna has optimal performances when the substrate size matches the patch size on the HRS substrate (Type-II). The antenna is redesigned to have a patch size of 0.81 × 1.18 mm² on the HRS substrate in the same size. It has an efficiency of 94.9% and a gain of 1.97 dBi at the resonant frequency of 60 GHz with an omni-directional radiation pattern. Compared to the initial design of the BTB patch antenna (Type-I), the optimal BTB patch antenna (Type-II) has a slightly higher efficiency and gain with a considerable reduction in antenna area by 34.8%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3642-3667
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• 2021

Texture synthesis technology has the advantages of repairing texture and structure at the same time. However, during the filling process, the size of the patch is fixed, and the content of the filling is not fully considered. In order to be able to adaptively change the patch size, we used the exemplar-based inpainting technique as the test algorithm, considering the image structure and texture, calculated the image structure patch size and texture patch size, and comprehensively determined the image patch size. This can adaptively change the patch size according to the filling content. In addition, we use multi-layer images to calculate the priority, so that the order of image repair was more stable. The proposed repair algorithm is compared with other image repair algorithms. The experimental results showed that the proposed adaptive image repair algorithm can better repair the texture and structure of the image, which proved the effectiveness of the proposed algorithm.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.464-467
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• 2003

In this paper, to reduce the patch size of microstrip antenna, folded surface-type patch antenna is designed and fabricated. Size reduction could be achieved because of the downed resonant frequency by the extended current path passing along below the transformated patch surface. Comparison of the patch size at the 1.575 GHz between plane type(length 82 mm${\times}$width 90 mm) and "ㄷ"-shaped folded type is carried and comparision of frequency variation at the same patch size is carried. The result is like that the patch size was reduced than the plane type by 60 mm(73.17 %) at the same frequency. Therefore, it could be checked that "ㄷ"-shaped folded type antenna is advantageous than the plane type in size reduction.

• 한국통신학회논문지
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• 제28권3A호
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• pp.166-170
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• 2003

In this paper, the characteristics of Koch island microstrip patch antenna are investigated by numerical and experimental methods. The Koch patch is fractal shaped antenna which can be characterized by two properties such as space-filling and self-similarity. Due to its space-filling property of fractal structure, the proposed Koch fractal patch antennas are smaller in size than that of conventional square patch antenna. From numerical and experimental results, it is found that as the iteration number and iteration factor of Koch patch increase, its resonance frequency becomes lower than that of conventional patch, thus contributes to antenna size reduction. In particular, when the fractal iteration factor is 1/4, the fractal antenna is 45% smaller in size than that of conventional patch, while maintaining radiation patterns comparable to those of rectangular antenna and cross polarization level is about -20~-14 dB.

• 한국전자파학회논문지
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• 제18권4호
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• pp.389-397
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• 2007

본 논문은 크기가 소형화된 광대역 기생 패치 안테나를 제안한다. 폭이 좁아진 주 패치의 두 방사 모서리부에 U자 형태의 기생 패치를 설계하여 안테나 전체 크기를 감소시키고, 주 패치와 기생 패치 사이의 E-plane 및 H-plane을 통한 electromagnetic coupling에 의해 광대역 특성을 얻는다. 안테나 방사 소자들의 전체 크기는 $18{\times}17.6\;mm^2$ 이고, 접지면과 유전체를 포함한 전체 크기는 $25{\times}30{\times}4\;mm^3$이다. 설계된 안테나는 FR4 유전체를 이용해 제작하였으며, 5.12 GHz와 6.08 GHz의 공진 주파수와 5.5 GHz 중심 주파수를 기준으로 27.3 %(1.5 GHz)의 대역폭을 갖는다. 측정된 안테나의 방사 패턴은 일반적인 마이크로스트립 패치 안테나와 유사하다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.473-477
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• 2003

In this paper, a integrated structure of a two-element microstrip patch antenna with two feeds for GPS/PCS dual-band operation is proposed. The radiating element for PCS operation is a novel broad band low-profile cylindrical monopole top-loaded with a shorted meander patch, which gives linearly polarized conical radiation pattern and size reduction of patch due to meander line. The radiating element for GPS operation is a novel square-ring microstrip patch with truncated corners and slits. which provide circularly polarized broadside radiation patterns and size reduction due to slots. using dielectric substrate in GPS antenna of proposed antenna provide to improve isolation between two feeds and reduce size of patch. The proposed antenna achieves the bandwidth and polarization requirements of GPS and PCS systems.

• Animal cells and systems
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• 제15권1호
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• pp.73-78
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• 2011

Estimating the habitat potential of inland forest patches for birds requires the modeling of species-area relationships, or relationships between habitat size and numbers of bird species in each patch. The accurate estimation of speciesarea relationships significantly reduces the effort required to recognize the number of species living in each patch. The objective of this study was to estimate the relationship between forest patch size and bird species diversity in Dangjin County, in northwest South Korea, based on the sizes of inland forest patches. KOMPSAT-2 images were obtained and ortho-rectified to construct a map of the target forest patches. The numbers of birds per patch were surveyed four times: August 2008, September 2008, February 2009 and May 2009. Regression models were derived to explain the relationships between the numbers of bird species and patch size. A model that was derived using data from all four observation periods had the highest coefficient of determination ($R^2$). According to these models, the numbers of bird species at first increased linearly with increasing patch size; however, the curve then plateaued. Our model including observations from four seasons will be useful for estimating the numbers of bird species in other inland forest patches in South Korea.

• 한국조경학회지
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• 제23권4호
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• pp.12-19
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• 1996

Urban parks, as remnant patches, of two older cities and two new towns can be analyzed by a landscape ecological approach. The index of patch shape, the dispersion of patches, the mean edge length, and the mean patch size of parks of each city are ocmpared. The findings of this study are as follows : 1) The mean edge length of urban parks of older cities is longer than that of new towns : Seoul>Suwon>Bundang>Ansan. 2) The mean patch size of urban parks in Seoul is much greater than those of other cities : Seoul> Ansan>Suwon>Bundang. 3) The index of patch shape of urban parks of older cities is greater than that of new towns : Seoul>Suwon>BundangAnsan. 4) The dispersion of patches is in the order of Bundang >Ansan>Seoul>Suwon. The new towns have relatively even distributions of urban parks than older cities. Further research is required to find out the relationship between the index of patch shape and patch interior dynamics.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.187-190
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• 2007

This study is for analyzing best band in image matching using correlation coefficient of left and right images of stereo image pair, lot red, green, blue band images separated from color aerial photo and gray image converted from the same color aerial photo image. The image matching is applied to construct Digital Elevation Model(DEM) or terrain data. The correlation coefficients and variation by change of pixel patch size are computed from pixel patches of which sizes are $11{\times}11{\sim}101{\times}101$. Consequently, the correlation coefficient in red band image is highest. The lowest is in blue band. Therefore, to construct terrain data using image matching, the red band image is preferable. As the size of pixel patch is growing, the correlation coefficient is increasing. But increasing rate declines from $51{\times}51$ image patch size and above. It is proved that the smaller pixel patch size than $51{\times}51$ is applied to construct terrain data using image matching.

• 한국환경복원기술학회지
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• 제8권5호
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• pp.56-67
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• 2005

Rapid and reckless economical development is causing nationwide deforestation; more and more forest is being developed to be used as a base for economic advancement. While benefiting the national economy, this destruction of forest is creating a serious problem in the National Land Plan. To solve this problem, it is imperative to understand the current condition of damaged forest and make an environment-friendly plan. This paper explains the principles of spatial plan and sets the criteria for the plan, such as patch size, connectivity, and edge of the Landscape Ecology. The paper assesses the conservational value of area that are currently being developed or planned to be developed to figure out the current environmental situation. This conservational value was verified by the field survey. The result of assessment appears that the patch size of the major mountains in site is over 1,000ha and edge is located widely beside roads. The area of the high connectivity is located agriculture area in valley or narrow roads. The research shows that the patch size is related to biodiversity the larger the patch size, the more populated the species are. The research also reveals the conservational value indicated by degree of connection to forest, difference in the structure of vegetation between core area and edge area, and effects of surrounding environment. In further study, we will assess other criteria of conservation value, such as patch shape and fragmentation to the Landscape Ecology, and apply those criteria in biological aspects of the spatial plan.