• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.9
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• pp.777-782
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• 2015

In this paper, the compact CPW-fed antenna with triple folded patch for dual-band WLAN applications is proposed. As the conventional double inverted-L antenna is changed into the C-shaped patch and double inverted-L antenna, the antenna overcomes the narrow-band characteristics according to the miniaturization of the antenna. The proposed antenna with the size of only $16.5mm{\times}29.5mm{\times}1.0mm$ is designed and fabricated by optimized parameters to be operated at 2.4 GHz band and 5 GHz band. The antenna is fabricated into FR-4 substrate with thickness of 1.0 mm. We confirm that it is operated as antenna for WLAN applications by obtaining the measured return loss level of < -10 dB at dual-band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.12
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• pp.1184-1187
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• 2011

In this letter, a planar monopole UWB antenna with dual band-notched characteristics is proposed. The band-stop characteristics is realized by embedding the 1st/3rd order Hilbert-curve slots on the patch. With the dimension adjustment of each Hilbert-curve slots, the band rejection from 3.3 to 3.7 GHz and from 5.3 to 6 GHz can be accomplished easily. The VSWR and radiation pattern of the fabricated antenna are measured, and the proposed antenna would be adequate to a UWB applications.

• Journal of Advanced Navigation Technology
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• v.21 no.2
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• pp.193-199
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• 2017

In the paper, a dual band-notched monopole antenna is proposed for 2.4 GHz WLAN (2.4 ~ 2.484 GHz) and UWB (3.1 ~ 10.6 GHz) applications. The 3.5 GHz WiMAX band notched characteristic is achived by a pair of L-shaped slots instead of the previous U-shaped slot on the center of the radiating patch, whereas the 7.5 GHz band notched characteristic is achived by C-shaped strip resonator placed near to the microstrip feed line. The measured impedance bandwidth (${\mid}S_{11}{\mid}{\leq}-10dB$) is 8.62 GHz (2.38 ~ 11 GHz) which is sufficient to cover 2.4 GHz WLAN and UWB band, while measured band-notched bandwidths for 3.5 GHz WiMAX and 7.5 GHz bnad are 1.13 GHz (3.15 ~ 4.28 GHz) and 800 MHz (7.2 ~ 8 GHz) respectively. In particular, it has been observed that antenna has a good omnidirectional radiation patterns and higher gain of 2.51 ~ 6.81 dBi over the entire frequency band of interest.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.242-250
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• 2004

In this thesis, a new broadband PIFA(Planar Inverted-F Antenna) for PCS and IMP-2000 applications is designed. The dual-L antenna structure is adopted in order to improve the characteristics of PIFA which usually has a narrow band. The height of the antenna is fixed 6 mm considering terminal's thickness and the structure is deformed into the folded radiation patches to minimize the size of the antenna. The bandwidth of a realized antenna is 1.66∼2.35 ㎓(34.5 %) fur return loss below -10 ㏈ which contain the required bandwidth of PCS and IMT-2000. And Monopole antenna with λ/4 length is designed and compared with dual-L with folded patch in SAR. 1 g and 10 g averaged peak SAR of PIFA are about 25.7 %, 30.3 % lower than those of monopole antenna respectively.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1611-1618
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• 2017

This paper presents a compact reconfigurable printed monopole antenna, operating in three different frequency bands (2.45 GHz, 3 GHz and 5.2 GHz), depending upon the state of the lumped element switch. The proposed multiband reconfigurable antenna is designed and fabricated on a 1.6 mm thicker FR-4 substrate having a relative permittivity of 4.4. When the switch is turned ON, the antenna operates in a dual band frequency mode, i.e. WiFi at 2.45 GHz (2.06-3.14 GHz) and WLAN at 5.4 GHz (5.11-5.66 GHz). When the switch is turned OFF, it operates only at 3 GHz (2.44-3.66 GHz). The antenna radiates omni-directionally in these bands with an adequate, bandwidth (>10 %), efficiency (>90 %), gain (>1.2 dB), directivity (>1.7 dBi) and VSWR (<2). The fabricated antenna is tested in the laboratory to validate the simulated results. The antenna, due to its reasonably compact size ($39{\times}37mm^2$), can be used in portable devices such as laptops and iPads.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.8
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• pp.899-905
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• 2008

In this paper, we propose a dual-spiral line loaded monopole antenna having a vertical ground plane for quadband applications. The antenna occupies a volume of $38{\times}12{\times}7\;mm^3$ with a $40{\times}92\;mm^2$ ground plane. The measured impedance bandwidths of the antenna based on $VSWR{\le}2$ are approximately of 11.7 % and 24.8 % in the first and second frequency band, respectively. The operating frequency can simultaneously cover Cellular($0.824{\sim}0.894\;GHz$), PCS($1.750{\sim}1.870\;MHz$), UMTS($1.920{\sim}2.170\;MHz$), and IMT-2000($1.885{\sim}2.200\;GHz$) bands. The maximum gains of the antenna are -0.99 dBi, 4.07 dBi, 2.72 dBi, and 4.33 dBi at the center frequencies of the Cellular, PCS, UMTS, and IMT-2000 bands, respectively. Good radiation patterns are experimentally obtained.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.885-894
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• 2015

In this paper, it can be applied to a walkie-talkie, the RFID / USN 920 MHz band(917~923.5 MHz) and WiFi 2.4GHz band(2.4~2.483 5GHz) return loss is 10 dB over the band, on-board dual band with omni-directional radiation characteristics is proposed. The basic structure designed antenna is used meander monopole antenna. It was used as double stubs and tabs for antenna designs that meet the criteria proposed. The double stub and the tab affects the reactance of the antenna to form a common-mode and differential-mode in the stub to improve the antenna characteristics and return loss in the bandwidth, gain and radiation characteristics. The system size of walkie-talkie is $52{\times}77mm^2$, the size of the antenna is limited to $52{\times}15mm^2$, the thickness of FR4 dielectric substrate is 0.8 mm, FR4 dielectric constant 4.4 is used. For experimental results, the return loss is measured more than 10 dB, the maximum gain is measured 1.95 dB, the maximum bandwidth is measured 360 MHz, the radiation characteristic is measured omni-directional. By a walkie-talkie terminal design applying the results of the paper, the handset's price competitiveness and production efficiency can be improved.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.465-473
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• 2012

In this study, a novel dual band planar monopole antenna for wireless local area network (WLAN)/ Worldwide Interoperability of Microwave Access (WiMAX) application was designed, fabricated, and measured. The proposed antenna consists of two hook shaped strips, an asymmetric ground plane, and a rectangular slit in the ground plane. Acceptable agreements between the measured and simulated results are achieved. Numerical and experimental results demonstrate that the proposed antenna satisfies the 10 dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. This paper also presents and discusses the 2D radiation patterns and 3D gains according to the results of the experiment that was conducted.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.710-710
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• 2006