• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.9
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• pp.841-848
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• 2016

In this paper, a microstrip-fed dual-band monopole antenna with DGS(: Defected Ground System) for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two strip lines and DGS structure and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters W2, L10, W3, and DGS to get the optimized parameters. The proposed antenna is made of $21.0{\times}36.0{\times}1.6mm3$ and is fabricated on the permittivity 4.4 FR-4 substrate. The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 700 MHz(2.10~2.80 GHz) and 1,780 MHz(5.02~6.80 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4GHz band/5.0GHz band), respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1049-1056
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• 2017

In this paper, a microstrip-fed dual-band monopole antenna with two arc-shaped lines for WLAN(: Wireless Local Area Networks) applications was designed, fabricated and measured. The proposed antenna is based on a microstrip-fed structure, and composed of two arc-shaped lines and then designed in order to get dual band characteristics. We used the simulator, Ansoft's High Frequency Structure Simulator(: HFSS) and carried out simulation about parameters L2, L5, and with/without slit to get the optimized parameters. The proposed antenna is made of $13.0{\times}34.0{\times}1.0 mm^3$ and is fabricated on the permittivity 4.4 FR-4 substrate($12.0{\times}34.0{\times}1.0mm^3$). The experiment results are shown that the proposed antenna obtained the -10 dB impedance bandwidth 360 MHz (2.29~2.65 GHz) and 1,245 MHz (4.705~5.95 GHz) covering the WLAN bands. Also, the measured gain and radiation patterns characteristics of the proposed antenna are presented at required dual-band(2.4 GHz band/5.0 GHz band), respectively.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1250-1256
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• 2017

This paper proposes the design of microstrip patch antennas for dual-band polarization adjustment. The antenna has a multi-layer structure for dual-band operation, and each layer contains a resonating patch with surrounding strips separated into two parts. The antenna polarization is adjusted by varying the separated positions of the strips, while fixing other design parameters. To demonstrate the feasibility, an antenna sample with right-hand circular polarization is fabricated, and its antenna characteristics are measured in a full anechoic chamber. The operating principle of polarization adjustment in the dual frequency bands is also verified by observing near electromagnetic fields and the magnetic surface current density around the antenna.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.436-441
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• 2018

In this paper, a design method for a compact double dipole quasi-Yagi antenna with a V-shaped ground plane operating in dual bands including 2.45 GHz and 5 GHz wireless LAN frequency bands is studied. First, a quasi-Yagi antenna operating in the 2.45 GHz band is designed, and a V-shaped ground plane is used instead of a conventional strip ground plane to reduce the length of the antenna. A second dipole is connected to the dipole driver of the quasi-Yagi antenna for 2.45 GHz band and a director is appended for 5 GHz band operation. A prototype of the proposed dual-band antenna operating at 2.45 GHz WLAN band and 4.57-7.11 GHz band is fabricated on an FR4 substrate with a dimension of 40 mm by 55 mm. Fabricated antenna shows frequency bands of 2.33-2.75 GHz and 4.38-7.5 GHz for a voltage standing wave ratio less than 2. Measured gain remains more than 4 dBi in both bands.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.2
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• pp.75-79
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• 2015

In this paper, a dual band antenna with the operating frequency in HF and UHF band was proposed. The antenna structure consists of three spiral turns coil in the bottom side to generate the HF frequency of 13.56 MHz. In the top of the antenna, an inverted-spiral dipole structure is used to create the UHF frequency of 922 MHz. The dual band antenna was optimized to reduce size with $80mm{\times}40mm{\times}0.8mm$ dimension. The antenna presents the omnidirectional characteristic with high gain. To validate the theoretical design, the antenna was simulated using FR-4 substrate and verified the simulation results.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.309-315
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• 2010

A dual-band dual-polarized microstrip antenna array for an advanced multi-function radio function concept (AMRFC) radar application operating at S and X-bands is proposed. Two stacked planar arrays with three different thin substrates (RT/Duroid 5880 substrates with $\varepsilon_r$=2.2 and three different thicknesses of 0.253 mm, 0.508 mm and 0.762 mm) are integrated to provide simultaneous operation at S band (3~3.3 GHz) and X band (9~11 GHz). To allow similar scan ranges for both bands, the S-band elements are selected as perforated patches to enable the placement of the X-band elements within them. Square patches are used as the radiating elements for the X-band. Good agreement exists between the simulated and the measured results. The measured impedance bandwidth (VSWR$\leq$2) of the prototype array reaches 9.5 % and 25 % for the S- and X-bands, respectively. The measured isolation between the two orthogonal polarizations for both bands is better than 15 dB. The measured cross-polarization level is ${\leq}-21$ dB for the S-band and ${\leq}-20$ dB for the X-band.

• Journal of electromagnetic engineering and science
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• v.18 no.4
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• pp.215-220
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• 2018

This study presents a dual-band polarization-reconfigurable antenna that comprises a large square patch with a pair of corner-cut edges and two small square patches with a shorting via. Two PIN diodes are located between the large square patch and two small square patches. Depending on the bias state applied to the two PIN diodes, each small patch may be disconnected or connected to the large square patch. As a result, the proposed antenna can provide polarization reconfigurability between two orthogonal linear polarizations. Further, the proposed antenna operates at 2.51 GHz and 2.71 GHz. From the measured results, the proposed antenna shows a 10 dB bandwidth of 2.39% (2.49-2.55 GHz) and 2.58% (2.68-2.75 GHz). In this work, the frequency ratio can be easily controlled by changing the size of the small patch.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.4
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• pp.811-817
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• 2014

In this paper, a design method for a dual-band monopole antenna operating in the bands of 2.45 GHz WLAN and UWB is studied. A monopole antenna operating in UWB band is first designed, and a slot is inserted on the monopole to operate in 2.45 GHz WLAN band. The optimized dual-band monopole antenna is fabricated on an FR4 substrate, and the experimental results show that the antenna has a dual-band characterisitc in WLAN and UWB bands with the frequency bands of 2.35-2.50 GHz and 2.99-11.82 GHz for a VSWR < 2. Measured gain is 1 dBi at 2.45 GHz, and ranges 1.5-4.6 dBi in the frequency band of 3.1-10.6 GHz.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.215-218
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• 2002

In this paper, a dual-frequency printed slot antenna loaded with an open-ring conducting strip and capacitively fed by a coplanar waveguide(CPW) is designed. The designed antenna has a bandwidth of 240㎒(1690㎒-1930㎒) at PCS frequency band and of 160㎒(2380㎒-2540㎒) at WLAN frequency band. In both frequency ranges, pattern and gain requirements are satisfied. The commercial software, IE3D, was used to design slot antenna. The predicted characteristics along with measured data are presented for verification purpose.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.2016-2021
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• 2009

In this paper, a dual-band antenna aimed for a mobile communication repeater was designed and measured. The operating frequency ranges are GSM(870${\sim}$960 MHz) and WCDMA(1920${\sim}$2170 MHz) bands. Experimental and numerical studies are performed for various design variables such as slot lengths. Using two meandering slots in the ground plane, we can obtain two higher resonant frequencies significantly with broader bandwidths. The measured maximum gain of antenna is 2 dBi in the GSM band and 2.45 dBi in the WCDMA band.