• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.1
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• pp.86-92
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• 1999

This paper proposed a small type ofen-loop antenna model for the moisture sensor, and its operating characteristics were analyzed numerically using the moment methods. The numerical analysis results through the moment methods showed that this antenna was able to match the input impedance to 50$\Omega$ by changing parameters of the antenna in the frequency range from 300MHz to 500MHz. The gain of antenna was obtained about 2.5dBd. This antenna proposed in this paper showed not only the radiation pattern characteristics of the uniform distribution toward the axial direction above the antenna, but also the narrowband resonant characteristics. Thus we can propose that the antenna be more suitable for the moisture sensor.

• Transactions on Electrical and Electronic Materials
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• v.18 no.2
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• pp.119-123
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• 2017

This paper presents a unique and miniaturized dual-band coplanar waveguide (CPW-fed) antenna for modern wireless communication. A new technique of using a modified ground structure (MGS) and frequency shifting strips (FSS) has been employed in the design to achieve dual-frequency operation. The proposed antenna generates two separate impedance bandwidths and covers the minimum required frequency bands of GSM 1800, GSM 1900, and Wi-Fi/WLAN 5 GHz. The proposed antenna is relatively small ($17{\times}20mm^2$) and operates over frequency ranges 1.51~2.06 and 4.43~6.70 GHz. The designed antenna was simulated using Ansoft HFSS, a FEM based simulator, and antenna characteristics, such as reflection coefficient, gain, radiation efficiency, radiation pattern, impedance bandwidth, VSWR, surface current, and electric field distributions, are reported in this paper. The effect of the antenna's key structural parameters on its performance is also analyzed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1265-1271
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• 2008

In this paper, we propose a new antenna design method for RFID tass on metallic surfaces using a low-cost, high-loss substrate such as FR4. The proposed design method highly reduces the substrate loss due to its dielectric loss, and so improves the radiation efficiency of the tag antenna more than double compared with a conventional PIFA(planar inverted-F antenna). The equivalent circuit model of the antenna according to the proposed method was established and its characteristics were analyzed systematically in this paper. The excellency of the proposed design method was verified by the fabrication and measurement of a prototype antenna.

• Journal of Satellite, Information and Communications
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• v.9 no.1
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• pp.38-44
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• 2014

In this paper, we designed a multiband monopole antenna for next-generation WLAN system. In conventional WLAN system, UWB antennas were used together, and, because the radiation occurs in different parts depending on the antenna structure, it has the disadvantage of having an unstable impulse response characteristic due to dispersion characteristics. Although a UWB antenna that has suitable radiation pattern for WLAN band, it does not have good impedance matching and has severe echo. Therefore, in this paper, a monopole antenna was designed by using CPW power feed so that various impedances can be easily implemented when designing an antenna and more parameters can be derived that can be used for design for optimal performance.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.8
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• pp.73-80
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• 2020

The 3D printing of electronics has been a major application topics in additive manufacturing technology for a decade. In this paper, wireless power transfer (WPT) technology for 3D electronics is studied to supply electric power to its inner circuit. The principle of WPT is that electric power is induced at the recipient antenna coil under an alternating magnetic field. Importantly, the efficiency of WPT does rely on the design of the antenna coil shape. In 3D printed electronics, a flat antenna that can be placed on the printed plane within a layer of a 3D printed part is used, but provided a different antenna response compared to that of a conventional PCB antenna for NFC. This paper investigates the WPT response characteristics of a WPT antenna for 3D printed electronics associated with changes in its design elements. The effects of changing the antenna curvature and the gap between the wires were analyzed through experimental tests.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.5
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• pp.53-59
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• 2011

In this paper wideband dipole antenna that is usable as PCS/WCDMA/WiBro/WiMax public relay station antenna is proposed. The proposed antenna that designed by using double ring structure improves bandwidth performance of existing dipole antenna to wideband performance. To verify wideband performance and isotropic radiation pattern of the proposed antenna, simulation and fabrication have progressed its radiation characteristic has measured and then compared with calculated result. Measured result is similar to calculated result and has gain of 2dB VSWR of 2:1 over 1.75~3GHz. It is considered that the dipole antenna that designed in this paper can be usable as PCS/WCDMA/WiBro/WiMax public relay station antenna.

• Proceedings of the IEEK Conference
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• summer
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• pp.334-338
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• 2004

In this paper, we suggest a new antenna structure for RFID(Radio Frequency IDentification) reader. Conventional RFID reader uses a loop antenna. The central area of a loop antenna shows a low magnetic field strength especially for the case of a large loop antenna diameter. We propose a parallel-fed multiple loop antenna. Simulation results and measured results show that we can adjust field distribution with the number of turns and diameter of an inner loop antenna to obtain a longer reading distance. Simulation results for the specific case of a proposed antenna structure show that at the center point of a proposed parallel-fed multiple loop antenna, the typical card area averaged magnetic field strength is 2.53A/m, which is higher than the case of a conventional type single loop antenna of 0.44A/m and the case of a series-fed multiple loop antenna of 0.96A/m when we drive with same source signal. We realized the antenna for the case of 13.56MHz RFID reader and the performance of reading distance was much more improved than the case of a conventional antenna.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.5-8
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• 2004

In this paper, a novel 400MHz band small meander microstrip antenna is proposed the shape of the proposed antenna is a waved meander microstrip with a pair rf short pins on th￡ edge. the length of waved meander microstrip is $\lambda_g/4$ but it bends to half its size. Therefore, the total size of the proposed antenna is reduced to about 1/20 which is compared with a square patch antenna the simulated antenna gain is about 3dBi at 424MHz. the proposed antenna of -10dB impedance bandwidth is measured about $1.4\%$.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1660-1663
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• 2003

This paper present the characteristics of radiation pattern of microstrip slot antenna on the ground plane fed by microstrip line. It is proposed for resonance frequency at 10 GHz. We will analysis two shape of slot antenna; double L-shape slot antenna and U-shape slot antenna. In this case, we will compare far-field radiation pattern of two shape slot antenna. Far-field radiation pattern of double L-shape slot antenna is bi-directional nevertheless U-shape slot antenna is uni-directional. The microstrip slot antenna is propose to analyze far-field radiation pattern for use in the wireless communication systems

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.47-56
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• 2003

We describe a new method for removing non-linear phased array antenna aberration called "squint" problem. To develop a compensation scheme. theoretical antenna and artificial neural networks were used. The purpose of using the artificial neural networks is to develop an antenna system model that represents the steering function of an actual array. The artificial neural networks are also used to implement an inverse model which when concatenated with the antenna or antenna model will correct the "squint" problem. Combining the actual steering function and the inverse model contained in the artificial neural network, alters the steering command to the antenna so that the antenna will point to the desired position instead of squinting. The use of an artificial neural network provides a method of producing a non-linear system that can correct antenna performance. This paper demonstrates the feasibility of generating an inverse steering algorithm with artificial neural networks.