• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.8
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• pp.1796-1803
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• 2013

In this paper, a novel particle swarm optimization method based on IE3D is used to design a mobile communication microstrip patch antenna. The aim of the paper is to design and fabricate an inset fed rectangular microstrip antenna and study the effect of antenna dimensions length (L), width (W) and substrate parameters relative dielectric constant (${\varepsilon}r$), substrate thickness on radiation parameters of band width. PSO algorism was applied to IE3D, low resistance against, band width and advantage, were improved.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.1785-1790
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• 2014

In communication systems, there are various types of microstrip antenna that can be used for many applications. This paper mainly focuses on the simple design of inset fed rectangular microstrip patch antenna to operate at frequency of 2.45 GHz for wireless communication. The study involves using HFSS simulator to design the antenna dimensions and to determine its performance. This antenna is based on a thickness of 1.6mm Teflon substrate with a dielectric constant of approximately 2.2, on one side of the substrate and another side has a ground plane. After simulation, the antenna performance characteristics such as return loss, VSWR, gain, radiation pattern are obtained.

• 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 TC
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• v.43 no.8 s.350
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• pp.103-109
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• 2006

In this paper, single-feed equilateral triangular microstrip antennas(ETMA) for circular polarization(CP) are designed and studied experimentally. It is demonstrated that by embedding a narrow slot or a cross of unequal slot lengths in the triangular patch circularly polarized radiation RHCP(right-hand circularly polarized wave), LHCP(left-hand circularly polarized wave) of microstrip antennas can easily be achieved using by strategically positioned coaxial single probe feed. And the size of a triangular microstrip patch antenna is smaller than that of a conventional rectangular or circular patch at a given frequency. A single-feed ETMA with a horizontal narrow slot is printed on the substrate of 60 mils thick and the other ETMA with a corss slot of unequal slot lengths is printed on the same substrate. The antenna radiation characteristics are calculated by ENSEMBLE(Ver. 5.0) software, and compared with the experimental results. This results show that the antenna size reduction of about $17%{\sim}2l%$ is obtained as compared to the regular-size CP design.

• Journal of Korean Society of Steel Construction
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• v.27 no.4
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• pp.359-370
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• 2015

This paper presents the experimental results for the interfacial bond behaviour between AFRP strip and steel members. The objective of this paper is to examine the interfacial behavior and to evaluate the interfacial bond stress between Aramid FRP strips and steel plates. The test variables were bond length and AFRP thickness. 18 specimens were fabricated and one-face shear type bond tests were conducted in this study. There were two types of failure mode which were debonding and delamination between AFRP strip and steel plates. From the test, the load was increased with the increasing of bond length and AFRP thickness, which was observed that maximum increase of 63 and 86% were also achieved in load with the increasing of bond length and AFRP thickness, respectively. Finally, bond and slip characteristics had the elastic bond-slip model and it was observed that bond strength and fracture energy were not affected by bond length and AFRP thickness.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.49-59
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• 2014

Effects of the dielectric constant and thickness of a feed substrate on the bandwidth and radiation characteristics of an aperture coupled microstrip patch antenna (ACMPA) are investigated. The optimized return loss bandwidth of an ACMPA increases without the degradation of radiation characteristics as the feed substrate dielectric constant increases for the same feed substrate thickness. The optimized return loss bandwidth of an ACMPA with the dielectric constant of a feed substrate of 10, which is compatible with the high dielectric constant monolithic microwave integrated circuit (MMIC) materials, increases without the degradation of radiation characteristics as the thickness of a feed substrate decreases. The ACMPA configuration is suitable for integration with MMICs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3A
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• pp.424-429
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• 2000

In this paper, the characteristics of the asymmetric coupled microstrip(ACM) lines with finite metalization thickness are investigated using the quasi-static analysis in the multilayered structure. By mode-matching method as the quasi-static analysis. the characteristic impedances and effective dielectric constants in ACM lines are obtained as a function of metalization thickness. The numerical results show that the propagation characteristics of ACM lines in the single and multilayered structure will be changed by the variation of metalization thickness.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.9
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• pp.29-39
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• 2001

Dielectric cover effect of rectangular microstrip patch antenna on uniaxial substrates with airgap are studied. First, we derive Dyadic Green function for selected anisotropic material by constitutive relation and then formulate integral equations of electric fields using Fourier transform in space region. Using Galerkin's moment method, we discretize the electric field integral equations into the matrix form and select sinusoidal functions as basis functions. We verify the validity of numerical results and compare the results with existing ones in showing a good agreement between them. When the dielectric cover thickness is varied, the resonant frequencies and input impedances in the variation of air gap, patch length and thickness and permittivity of superstrate are presented and analyzed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.05a
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• pp.223-227
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• 2001

To complement the narrow band characteristics of the microstrip patch antenna, the slot patch antenna was designed for the wide band characteristics. The microstrip slot patch antenna has wide band characteristics when the size of the slots and the feed line shapes are designed accordingly. In this study, various substrates as a epsilon-10, and a epoxy were used to design slot patch antennas. The feed line structure of the circular and square were also designed to have wide band. In the case of slot antennas with the circular patch shapes using epsilon-10 plate 50mm thickness with relative permittivity the 41% bandwidth on the 1.5∼2.28㎓ was shown. When an Epoxy plate 1.Sum thickness with relative permittivity 4.75 is used to construct a circular slot antenna with a square patch form, the frequency band width was obtained 77% as the 1.2∼2.7㎓ frequency range. These results are coincided well with the theoretical results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.11 s.114
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• pp.1040-1049
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• 2006

A design method for minimizing transmission loss of a broadband right-angle transition from a coaxial cable to a microstrip line is presented. The right-angle transition has been widely used where printed circuit applications need to be fed from behind the ground plane using coaxial line. To obtain the minimized transmission loss over the whole operating frequency range of the transition, design parameters such as ground aperture and probe diameters, ground aperture offset, and stub length are optimized using a commercial electromagnetic simulation software. Results are presented for the optimum right-angle transition from an SMA connector to a microstrip line on common reinforced 0.787 mm thick PTFE substrates. Measurements of a fabricated transition show that reflection coefficient is less than -22 dB and insertion loss is less than 0.45 dB over $0.05{\sim}20GHz$.