• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.73-78
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• 2007

In this paper, the CPW-fed triple-band internal planar monopole antenna which simultaneously meets the three bands such as Cellular, PCS and Wibro is designed. The size of the radiation elements can be reduced to about $\lambda/4$ by designing the CPW-fed monopole antenna and then we can miniaturize the antenna size by meandering the radiation elements. In addition, we design the planar antenna for the slim-type mobile phone. We can obtain the desired antenna properties by controlling the length of each radiation elements. The measured return loss of the antenna is less than -7 dB at the desired bandwidth. And the measured radiation patterns are similar to that of the monopole antenna. The designed antenna has the gains -5.2 dBi. -2 dBi, -0.4 dBi at each resonant frequencies respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.30 no.3
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• pp.181-189
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• 2019

In this study, a triple-band antenna that can be used in WLAN(Wireless Local Area Network) at 2.4 GHz, 5.8 GHz, and 5G at 3.5 GHz is fabricated. The proposed antenna uses a parasitic element to show the triple band, and the reflector is used at a distance of ${\lambda}/4$ from the antenna to reduce the Specific Absorption Rate(SAR). Its dimensions are $100{\times}75{\times}1.6mm^3$ and each parameter value is optimized for better performance and a lower SAR value. As a result, we obtained a bandwidth of 540 MHz(2.02~2.56 GHz), 390 MHz(3.39~3.78 GHz), and 1,210 MHz(5.56~6.77 GHz) based on the reflection loss factor of -10 dB. In addition, the SAR values of the antenna with reflector are observed to reduce below the SAR value of international standard.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.3
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• pp.341-348
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• 2019

In this paper, a monopole type antenna applicable to WLAN and WiMAX standard frequency bands is designed and fabricated. The proposed antenna is designed to have rectangular ring and rectangular patch based on microstrip feeding for triple band characteristics and inserted two stub in the top of the rectangular ring patch to enhance impedance bandwidth characteristics. The proposed antenna has $18.0mm(2W_1+W_2){\times}33.0mm(L_7+L_8+L_9)$ on a dielectric substrate of $27.0mm(W_1){\times}44mm(L_1){\times}1.0mm$ size. From the fabrication and measurement results, impedance bandwidths of 660MHz (2,08 to 2.74GHz) for 2.4/2.5MHz band, 488MHz (3.40 to 3.88GHz) for 3.5MHz band, and 2,180MHz (4.61 to 6.79GHz) for 5,000MHz band were obtained based on the impedance bandwidth. The proposed antenna also obtained the measured gain and radiation pattern in the anechoic chamber.

• Journal of the Korea Society of Computer and Information
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• v.10 no.1 s.33
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• pp.175-180
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• 2005

Transmission speed becomes high speedization gradually in system while is the latest microwave and millimeter wave communication and user's demand is trend that also increase rapidly. To accommodate wider band width therefore, signalman who have high frequency and not required welsh suppression special quality little more is required. Designed oscillator, point Parts, in duplex all communication systems several systems studies that can keep pace with a lot of amount of informations in modern info-age are archieved vigrously.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.1 s.92
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• pp.66-77
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• 2005

This paper proposed a novel broadband PIFA(Planar Inverted-F Antenna) for IMT-2000/WLAN/DMB terminal. Two branch lines for meander line were utilized in order to improve the characteristics of PIFA which usually has a narrow band. The shorting strip between the ground plane and meander-type radiation elements were used in order to minimize the size of the antenna. The -10 dB return loss bandwidth of a realized antenna was $38.2{\%}$(1.84~2.71 GHz), which contains the broadband bandwidth with triple band. And the simulated and measured values of 1 g and 10 g averaged peak SAR on human head caused by the triple band PIFA mounted on folder-type handsets were analyzed and discussed. As a result, the measured 1 g and 10 g averaged peak SARs of PIFA were similar with the simulated values and were lower than the 1.6 W/kg and 2 W/kg of 1 g and 10 g averaged peak SAR limits.

• ETRI Journal
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• v.30 no.5
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• pp.735-737
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• 2008

We propose a novel spatial multi-band-stop filter using modified multiple loop array elements to block electromagnetic waves or signals of mobile phones in public facilities. It operates at the following frequency bands: Korean cellular (824 MHz to 894 MHz), Personal Communication Service (PCS) (1.75 GHz to 1.87 GHz), and IMT-2000 (1.92 GHz to 2.17 GHz). Two frequency selective surfaces with modified multiple-loop elements are printed on the top and bottom of a pair-glass pane, which is a pair of glass panes with an air gap between them. A modified multiple-loop element with a meander line is used to make the size of the filter compact. The simulated and measured results show good agreement, which confirms the usefulness of the proposed tri-band spatial filter.

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.220-223
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• 2004

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.5
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• pp.528-536
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• 2010

A monopulse feeder gives the most important impact upon the radiation pattern characteristics of a multi-function radar or a tracking radar which uses the space feed. It is described that the triple-mode type monopulse feeder which possesses the optimum aperture illumination for three monopulse channels is designed and measured in this paper. The measured results show that the designed feeder has not only the characteristics of the optimum aperture illimination in each channel and also very low return loss over the 10 % of fractional bandwidth at X-band. This means that the feeder provides the antenna system with low sidelobe level and high monopulse slope characteristics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.8
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• pp.1429-1435
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• 2010

In this paper, a double lorentz composite right left handed(DL-CRLH) transmission line is designed using defected ground structure (DGS) and varactor diodes. Previously, the diode has been adopted only selectively for one of parallel or series resonators, and the balanced frequency as well as triple band frequencies were fixed. However in the proposed DL-CRLH transmission line, the balanced frequency, where the resonant frequencies of the series-connected parallel resonator and shunt-connected series resonator are the same, is adjustable. In addition, the triple band frequencies are controlled, too. The measured balanced frequency varies between 3.42~4.8GHz according to the controlled bias voltage. Under the same bias condition for the balanced frequency, the adjusted frequencies are 2.22~2.77GHz, 3.7~5.2GHz, 7.32~8.23GHz, 3.42~4.8GHz, and 4.44~5.92GHz for the conditions that ${\beta}d=+0.5{\pi}$, $-0.5{\pi}$, 2nd $+0.5{\pi}$, ${\omega}_{\infty}$, and ${\omega}_o$, respectively.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.6
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• pp.585-593
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• 2015

In the nanoscale regime, many multigate devices are explored to reduce their size further and to enhance their performance. In this paper, design of a novel device called, Triple Material Surrounding Gate Tunnel Field effect transistor (TMSGTFET) has been developed and proposed. The advantages of surrounding gate and tunnel FET are combined to form a new structure. The gate material surrounding the device is replaced by three gate materials of different work functions in order to curb the short channel effects. A 2-D analytical modeling of the surface potential, lateral electric field, vertical electric field and drain current of the device is done, and the results are discussed. A step up potential profile is obtained which screens the drain potential, thus reducing the drain control over the channel. This results in appreciable diminishing of short channel effects and hot carrier effects. The proposed model also shows improved ON current. The excellent device characteristics predicted by the model are validated using TCAD simulation, thus ensuring the accuracy of our model.