• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.27-30
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• 2016

in this paper, to improve the narrow bandwidth problem of the microstrip antenna for WLAN and WiFi dual band array antenna was designed to satisfy the bandwidth of 3.6GHz and 5.2GHz it contained with IEEE 802. 11. The substrate of proposed microstrip array antenna is FR-4(er=4.3) and $25mm{\times}45mm{\times}0.8mm$ size and thickness t=0.035mm, and the simulation was used for CST Microwave Studio 2014. input return loss compared -10dB less than operates at and when gain 3.6GHz 2.516dB, 5.2GHz showed the results of 3.581dB. the antenna designed to be miniaturized and the be used in electronic devices such as mobile phone.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.625-630
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• 2011

In this paper, spiral meander monopole printed antenna for dual band operation in GPS(1.57~1.577 GHz) and WiBro(2.3~2.4 GHz), WLAN(2.4~2.48 GHz) is proposed. Spiral(positive coupling) mounted end of monopole(small current) and meander mounted fed of monopole(big current) for reduce frequency ratio. Bandwidth(-10 dB) of the antenna is measured 130 MHz(1.49~1.62 GHz) in basic resonance frequency and 330 MHz(2.29~2.62 GHz) in harmonic resonance frequency($3{\lambda}_H/4$). The peak antenna gains are measured 2.86 dBi in GPS(1.57 GHz), and 3.49 dBi in WiBro(2.35 GHz), and 3.71 dBi in WLAN(2.44 GHz).

• ETRI Journal
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• v.35 no.1
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• pp.150-153
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• 2013

In this letter, a compact and fully printed composite right- and left-handed (CRLH) dual-band power divider is proposed. The branches of the conventional Wilkinson power divider are replaced by subwavelength CRLH phase-shift lines having $+90^{\circ}$ for one frequency and $-90^{\circ}$ for another frequency for dual-band and miniaturization performance. Equations are derived for the even- and odd-mode analysis combined with the dual-band CRLH circuit. A PCS and a WLAN band are chosen as the test case and the circuit approach agrees with the CAD simulation and the measurement. Additionally, the CRLH property is shown with the dispersion diagram and the eightfold size reduction is noted.

• Journal of IKEEE
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• v.20 no.1
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• pp.68-74
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• 2016

In this paper, we present a compact planar dual band rejection Ultra Wide Band(UWB) antenna with folded parasitic element. The proposed antenna is consist of a hexagonal planar radiation patch antenna with a folded parasitic element which is located over the top and bottom surface. In contrast with other antenna which rejects single band using one method, folded parasitic element rejects dual band using one simple structure. Owing to folded parasitic element, dual-rejected properties are achieved in the Worldwide Interoperability for Microwave Access(WiMAX), C-band, and Wireless Local Area Network(WLAN) bands. The bandwidth of the proposed antenna was measured as 3.1~10.6 GHz for voltage standing wave ratio(VSWR) less than 2, except for the dual rejection bands of 3.4~4.2 GHz and 5.15~6.00 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.9
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• pp.1633-1640
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• 2016

In this paper, we propose a open-ended rectangular microstirp patch antenna with fork-shaped feeding structure. This antenna extends the effective bandwidth by transforming single or multi resonant frequency and is designed planar monopole structure with microstrip line to satisfy the WLAN bands (2.4 - 2.484, 5.15 - 5.35, 5.25-5.825 GHz). The substrate is printed in 0.8 mm thickness on an FR-4 board. A commercial 3D simulation tool was used to analyze surface current and electromagnetic field distribution in order to analyze the operation mode and reconfiguration principle of antenna. According to the lengths of individual patches, simulated reflection loss was compared to obtain optimized values. When it was designed with the optimized values, it satisfied WLAN bands (2.380 - 2.710, 4.900 - 5.950 GHz), if the switch is off, and 2.4 WLAN band (2.380 - 2.710 GHz). From the fabricated and measured results, measured results of return loss, gain and radiation patterns characteristics displayed for operating bands.

• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.449-455
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• 2018

For the size reduction, we propose a microstrip-fed monopole antenna with half X-slot in the radiation patch and cover WLAN dual band 2.4 GHz band (2.4 ~ 2.484 GHz) and 5 GHz band (5.15 ~ 5.825 GHz). The frequency characteristics such as impedance bandwidth and resonant frequencies were satisfied by optimizing the numerical values of various parameters, while the reflection loss in 5 GHz was improved by using defected ground structure (DGS). The proposed antenna is designed and fabricated on a FR-4 substrate with dielectric constant 4.3, thickness of 1.6 mm, and size of $24{\times}41mm^2$. The measured impedance bandwidths (${\mid}S_{11}{\mid}{\leq}-10dB$) of fabricated antenna are 450 MHz (2.27 ~ 2.72 GHz) in 2.4 GHz band and 1340 MHz (4.79 ~ 6.13 GHz) in 5 GHz band which sufficiently satisfied with the IEEE 802. 11n standard in dual band. In particular, radiation patterns which are stable as well as relatively omni-direction could be obtained, and the gain of antennas in each band was 1.31 and 1.98 dBi respectively.

• Journal of Advanced Navigation Technology
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• v.22 no.4
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• pp.336-341
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• 2018

In this paper, we designed and implemented an ultra wideband (UWB) antenna with 5G mobile communication and WLAN bands rejection characteristics. The proposed antenna consists of a planar radiation patch with two slots, parasitic elements on both sides of the strip line and ground plane on back side. The upper n-type slot contributes for 5G mobile communication band (3.42~3.70 GHz) rejection and the lower n-type slot contributes for wireless local area network (WLAN) band (5.15~5.825 GHz) rejection. Parasitic elements were used in order to satisfy the voltage standing wave ratio (VSWR) less than or equal to 2.0 for UWB band (3.10~10.60 GHz) except two rejection bands. The Ansoft's high frequency structure simulator (HFSS) was used for antenna design and simulations. The simulated antenna showed dual rejection bands of 3.36~3.71 GHz and 5.13 ~ 5.92 GHz in UWB band, and measured result for the implemented antenna showed dual rejection bands of 3.40~3.72 GHz and 5.08~5.858 GHz. Simulated and measured VSWRs are less than or equal to 2.0 for all UWB band except dual rejection bands.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.213-217
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• 2014

In this paper, we designed monopole microstrip antenna for WLAN/WiMAX system. The monopole antenna is designed by FR-4 substrate with size is $30mm{\times}40mm$. The proposed antenna is based on a planar monopole design which cover WLAN and WiMAX frequency bands. To obtain the optimized parameters, we used the simulator, CST's Microwave Studio Program and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is designed. Thus the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are obtained for WLAN/WiMAX frequency bands.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.759-763
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• 2011

In this paper, a dual-band T-shaped microstrip monopole antenna with a pair of slits for 2.4/5.2/5.8-GHz wireless local area networks (WLANs) is proposed. A pair of T-shaped slits is loaded on a T-shaped monopole antenna fed by microstrip line in order to obtain dual-band operation as well as to reduce the antenna size. It is demonstrated from experimental results that the proposed antenna can cover all the required bands for WLAN. The measured impedance bandwidth for VSWR<2 is about 5.7% (2.37-2.51GHz) in the lower frequency band and about 28.8% (4.76-6.35GHz) in the higher frequency band. The measured peak gains are about 1.33 dBi to 1.66 dBi in the 2.4GHz band, 3.50 dBi to 3.95 dBi in the 5.25GHz band, and 2.06 dBi to 2.34 dBi in the 5.8GHz band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.10-18
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• 2014

In this paper, we propose a new frequency reconfigurable dual-band antenna. By using an electronically compact eighth-mode substrate-integrated-waveguide(EMSIW) resonator, we have designed a compact antenna, which performs dual-band movement by additionally loading a complementary split ring resonator(CSRR) structure. The EMSIW and CSRR structures are designed to satisfy the bandwidths of 1.575 GHz(GPS) and 2.4 GHz(WLAN), respectively. We load the CSRR with a varactor diode to allow a narrow bandwidth and to enable the resonance frequency to continuously vary from 2.4 GHz to 2.5 GHz. Thus, we realize a channel selection function that is used in the WLAN standards. Irrespective of how a varactor diode moves, the EMSIW independently resonates so that the antenna maintains a fixed frequency of the GPS bandwidth even at different voltages. Consequently, as the DC bias voltage changes from 11.4 V to 30 V, the resonance frequency of the WLAN bandwidth continuously changes between 2.38 GHz and 2.5 GHz, when the DC bias voltage changes from 11.4 V to 30 V. We observe that the simulated and the measured S-parameter values and radiation patterns are in good agreement with each other.