• Journal of IKEEE
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• v.7 no.2 s.13
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• pp.218-222
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• 2003

Even if using the standard field test which radiation of electric wave and measurement test equipment there are difficult thing that building test equipment. so, we can use the substitution test field. In this paper, for optimization analysis for homogeneous field structure of GTEM-CELL (Giga hertz Transverse Electro Magnetic Cell) that calculate electromagnetic field characteristic for variable of each structure and characteristic impedance inner conductor.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.12
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• pp.32-37
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• 2000

We proposed to a new method of the aperture coupled microstrip antenna with T-shaped feeding slot. We analyzed method of enhancing the bandwidth of the antenna using FDTD. And the antenna parameters are optimized to get maximum bandwidth. We also calculated the progress process of waves and the distribution of electric field in the time domain. We also calculated return loss, VSWR, input impedance, radiation pattern in the frequency domain by Fourier transforming the time domain results, respectively. It was found that the bandwidth of this antenna changes length and width of the patch, length and width of the slot, length of T-shaped feedline, position of the offset. Measured % bandwidth was 49.2 % in the center frequency 2.5 GHz. These results were in relatively food accordance with calculated values.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.915-921
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• 2004

In this paper, we propose a printed monopole antenna called the saw tooth monopole antenna(STMA) with a very wide band. And impedance matching of the antenna for the wideband is achieved using a special matching structure to vary ground size of back plate. The proposed antenna is smaller than general $\lambda$/4 monopole antenna in size but provides a 2:1 VSWR bandwidth of about $89.6\%$. The radiation pattern is omni-directional at 0.8 GHz$\~$2.0 GHz with gain of about -0.02 dBi$\~$2.54 dBi.

• Journal of electromagnetic engineering and science
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• v.15 no.1
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• pp.6-13
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• 2015

In this paper, a novel monopole antenna for WLAN/WiMAX application is presented. The proposed antenna consists of two arc-shaped strips, a vertical strip, and a slot in the ground plane. In this study, a prototype of the proposed triple-band antenna was designed, fabricated, and tested. The quantitative and experimental results demonstrate that the proposed antenna satisfy the -10 dB impedance bandwidth requirement of 440 MHz for 2.4/2.5 GHz bands (from 2.26 to 2.70 GHz), 970 MHz for 3.5 GHz bands (from 3.27 to 4.24 GHz), and 870 MHz for the GHz bands (from 5.08 to 5.95 GHz), while simultaneously covering the WLAN and WiMAX bands. In addition, the presented triple-band antenna has an omnidirectional radiation pattern at all three frequency bands with an antenna gain of 4.45 dBi for the lowest band, 2.04 dBi for the middle band, and 3.98 dBi for the highest band.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.5
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• pp.567-574
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• 2014

In this paper, a VHF antenna with monopole structure is designed and fabricated for marine wireless communication applications. The proposed antenna is based on a monopole design, and composed of circular ring and meander structure for VHF operation which cover VHF frequency bands. To obtain the optimized parameters, we used the simulator, Ansoft's High Frequency Structure Simulator(HFSS) and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is fabricated. The experiment results demonstrated that the proposed antenna satisfied the -10 dB impedance bandwidth requirement while covering the VHF bands. And measured characteristics of gain and radiation patterns are obtained for operating bands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.12
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• pp.2217-2226
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• 2007

In this paper, we propose a microstrip antenna with sufficient impedance bandwidths and gains for the 2.65GHz antenna which can be used in the satellite digital multimedia broadcasting. The prposed 2.65GHz satellite DMB bandwidth microstrip antenna is implemented on a substrate, which is small enough to be installed in practical mobile phones, and described simulation feature using by CST MicroWave Studio program. And also, we measured the antenna performance between the proposed antenna and the commercial antenna. From the analysis, it was found that the radiation pattern of proposed antenna is superior to the commercial antenna and an acceptable frequency band is more wider than the existing products.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.74-75
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• 2016

Various types of microstrip antennas can be used for many applications in wireless communication systems. In this paper, we studied a design method for a broadband dual-fed stacked microstrip patch antenna. The impedance bandwidth is improved by adjusting the sizes of main radiating patch and parasitic patch, the distance between the patches, the length of inset feed line, etc. The antenna is designed by simulation for an operation in the frequency range of 2.3-2.7 GHz, and the antenna characteristics such as return loss, gain, radiation patterns are examined.

• Composites Research
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• v.20 no.2
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• pp.27-31
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• 2007

"Structural surface becomes an antenna." This term, CAS, indicates antenna embedding in structural surfaces. The CAS is composed of several composite laminates and Nomex honeycombs, and microstrip antenna elements are inserted between layers with designed configurations. Constituent materials are selected considering electrical contributions as well as mechanical performances. Antenna design with adhesive films are impossible because of their thin and rough distributions between honeycomb and substrate. Therefore, adhesive effects on antenna performances in CAS are experimentally investigated, CAS with targeted impedance and radiation characteristics are designed considering adhesive effects. multilayer

• Journal of the Korean Electrochemical Society
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• v.16 no.2
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• pp.91-97
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• 2013

Solid polymer electrolyte films are prepared by ultraviolet radiation in the mixtures of an ionic liquid salt (1-ethyl-3-methylimidazolium tetrafluoroborate, $EMIBF_4$) and solvent (acetonitrile (ACN) or propylene carbonate(PC)), and an oligomer (poly(ethylene glycol)diacrylate, PEGDA, 45-60 wt.%). Electrochemical properties of activated carbon supercapacitors adopting the solid polymer electrolyte films as a separator are also examined by cyclic voltammetry and impedance measurement techniques. As a result, the supercapacitor adopting the PEGDA as much as 45 wt.% exhibits a superior capacitance of $46Fg^{-1}$ at $20mVs^{-1}$. It seems that this is due to fast kinetics of ion conduction by sufficient film flexibility, which can be allowed by comparatively weak ultraviolet curing of small anount of the PEGDA.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.523-532
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• 2008

In this paper, we proposed a U-shaped RFID tag antenna with isotropic radiation characteristic for the stable operation of RFID system. The proposed antenna is composed of a U-shaped half wavelength dipole and a rectangular-shaped feed. In order to have good impedance matching with a tag chip, the commercial tag chip is attached to the lower center of the feed. A gain deviation characteristic of the U-shaped tag antenna can be further improved by inserting a rectangular slit in the lower center of the U-shaped antenna body. On the condition of VSWR<2, the tag antennas of two structures satisfy the Korea UHF RFID bandwidth and showed the gain deviation of less than 1.63 dB and 0.74 dB for without slit and with slit, respectively. On the condition of VSWR<5.8, the U-shaped tag antenna showed the gain deviation of less than 3.8 dB and 1.2 dB for without slit and with slit, respectively.