• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.6
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• pp.17-23
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• 2021

In the present study, a more compact dual-band slot antenna is newly proposed for Wi-Fi application. The proposed antenna is composed of rectangular two stepped slot with open end which can generate standing wave resonance at dual frequency bands and L-type microstrip feed line. The measured impedance bandwidths are 50 MHz(2.412 ~ 2.470 GHz) at low frequency band and 452 MHz(5.451 ~ 5.903 GHz) at high frequency band respectiviely. Furthermore its size of 14 × 21 mm² is reduced by 30% compared to the size of 20 × 21 mm² of a conventional similar compact slot antenna. It has the omni-directional radiation pattern characteristics of a typical dipole antenna on the H-Plane, so it is suitable for commercial wireless network applications such as Wi-Fi.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.127-134
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• 2022

A modified folded monopole slot antenna for 3G WCDMA (1.91 ~ 2.17 GHz), 4G LTE (2.17 ~ 2.67 GHz), 3.5 GHz 5G (3.42 ~ 3.7 GHz) and Wi-Fi dual band (2.4 ~ 2.484 GHz / 5.15 ~ 5.825 GHz) was proposed for the first time. 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 35 × 60 mm². The measured impedance bandwidth of the proposed antenna is 2910 MHz(1.84 ~ 4.75 GHz) and 930 MHz(5.11 ~ 6.04 GHz), antenna gain in each frequency band is from 1.811 to 3.450 dBi. In particular, it was possible to obtain a commercially suitable omni-directional radiation pattern in all frequency bands of interest.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.5
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• pp.552-559
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• 2011

In this paper, the frequency reconfigurable antenna is proposed and designed. The proposed antenna is designed using the vertically stacked dipole structures and have the operating band for Cellular, PCS/WCDMA/Wibro/WiFi and WiMAX. The operating frequency band is selected by three pair of PIN diodes using the voltage difference between each dipole antenna and feeding transmission lines. The proposed antenna meets the required operating bandwidth and the maximum gain for each frequency band are measured as 6.3 dBi, 5.4 dBi and 5.8 dBi, respectively. The proposed antenna in this paper can be applied for the future mobile small base station or repeater antenna because this antenna can provide the small size and high gain features.

• Journal of Advanced Navigation Technology
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• v.15 no.2
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• pp.197-203
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• 2011

A triple-band antenna which can be used at GSM900, PCS1900 and Bluetooth(or Wi-Fi) frequency band is proposed. The proposed antenna is designed based upon switching between IFA(Inverted F Antenna) that has a resonant length of ${\lambda}/4$ and loop antenna that has a resonant length of ${\lambda}/2$. It can be applied to triple-band only by use of single printed pattern due to the switching characteristic. It is designed by use of the IFA for the application to the GSM900, while it is designed by use of the loop antenna for the application to the PCS1900 and by use of additional pattern of IFA for the application to the Bluetooth(or Wi-Fi) respectively. As a result, it has been observed that the proposed antenna satisfies the required return loss(${\leq}10dB$) and also has efficiency(${\geq}80%$) over the whole band. Moreover the proposed antenna has omni-directional radiation pattern which is suitable to apply to the mobile phone.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.41-47
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• 2013

This letter describes a dual-band compact monopole antenna with two branches for Wi-Fi applications. The proposed antenna is based on a planar monopole design, and composed of two branches of radiating patches for dual-band operation. The ground size of the antenna matches the ground size of a typical hand-held cellular phone for improved compatibility with mobile phone printed circuit boards. The antenna is designed using a simulator and fabricated with optimized parameters. The fabricated antenna is measured at the lower and higher operating frequencies, and the return loss coefficient, gain, and radiation patterns are determined.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.944-949
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• 2015

This study proposed a patch antenna with a MIMO structure which is applicable for wireless communication equipment by combining a single patch antenna with a multi port. The proposed MIMO patch antenna was designed through the TRF-45 substrate with a relative permittivity of 4.5, loss tangent equal to 0.0035 and dielectric high of 1.6 mm, and the center frequency of the antenna was 2.45 GHz in the ISM (Industrial Scientific and Medical) band. The proposed MIMO patch antenna had a 500 MHz bandwidth from 2.16 ~ 2.66 GHz and 24.1% fractional bandwidth. The return loss and VSWR were -62.05 dB, 1.01 at the ISM bandwidth of 2.45 GHz. The Wibro band of 2.3 GHz was -17.43 dB, 1.33, the WiFi band of 2.4 GHz was -31.89 dB, 1.05, and the WiMax band of 2.5 GHz was -36.47 dB, 1.03. The radiation patterns included in the bandwidth were directional, and the WiBro band of 2.3 GHzhad a gain of 4.22 dBi, the WiFi band of 2.4 GHz had a gain of 4.12 dBi, the ISM band of 2.45 GHz had a gain of 4.06dBi, and the WiMax band of 2.5 GHz had a gain of 3.9 6dBi.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.10
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• pp.1338-1343
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• 2018

MIMO(Multiple Input Multiple Output) slot antenna that operates on the dual WiFi band(2.401~2.495GHz, 5.18~5.825GHz), in this paper, was studied. The basic theory for the slot design is based on the coupling between adjacent slot, and slots are fed by the each microstrip lines. Two slot antennas for the MIMO operation are located on the left and the right side of top of the metal notebook, and grounds between a notebook and two microstrip feeding lines are connected. Measurement of return loss showed under -6dB on entire design band, and isolation was below than -30dB. Radiation efficiency, average gain and peak gain for the left and the right slot were measured in the anechoic chamber, and showed good performances as 57.25%, -2.42dBi, 5.64dBi and 55.35%, -2.61dBi, 6.42dBi for the 2.4GHz band and 55.89%, -2.58dBi, 7.3dBi and 53.79%, -2.8dBi, 7.54dBi for the 5GHz band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.4
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• pp.424-430
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• 2012

A ground radiation antenna is designed using a capacitor connected between two ground points by a strip line. This paper analyzes the variations of radiation performance when changing the capacitor position. The surface current distribution of the ground antenna was investigated as the capacitor position is changed, in order to demonstrate the effects on the impedance bandwidth and antenna efficiency. Our antenna is for the Wi-Fi application. It is verified that the capacitor at the end of the strip line provides a wide impedance bandwidth(7.2 % at the 2.45 GHz frequency) and good antenna efficiency(measured as 66 % averaged over the overall Wi-Fi frequency band).

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.4
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• pp.43-49
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• 2013

In this paper, it is designed inverted triangle structural planar monopole antenna with edge and rectangle slot for UWB(Ultra Wide Band) communication (3.1~10.6 GHz) and researched in about 5.8 GHz notch structure to prevent interference between UWB systems and existing wireless systems for using Wi-Fi service. The antenna have broadband property structurally through inverted triangle structural planar monopole which have edge. and rectangle form addition planned notch slot of 1 mm and height 0.1 mm. Monopole and ground of proposed antenna exist on coplanar plane, and excite as CPW. It used FR4 epoxy dielectric substrate of ${\varepsilon}r$=4.4, and the size is $20{\times}20{\times}1.6$ mm dimension. The measured results that are obtained return loss under -10 dB through 3.1~10.6 GHz(7.5 GHz) without Wi-Fi bandwidth and maximum gain of 8.44 dBi at E-plane. Radiation pattern is about the same that of dipole antenna at all frequency. And using notch slot and it will be able to confirm the quality which becomes notch from 5.8 GHz which are a radio LAN frequency range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.265-274
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• 2011

In this paper, it is studied on wide radiating slot antenna's miniaturization for ultra wide-band(UWB) technologies and notch structure to prevent interference between UWB systems and existing wireless systems for using Wi-Fi service of IEEE standards 802.11 a/n. Proposed antenna that wide slot is decreased from $\lambda/2$ to $\lambda/4$ length of resonant frequency has decreased by 72 % compared with conventional antenna. And optimized T-shaped CPW-fed stub has satisfied UWB bandwidth for 3.0~11.8 GHz. Then, creating 2-order Hilbert curve slot line in the stub's patch area, 4.9~5.6 GHz that centered frequency is 5 GHz is eliminated. Finally, the designed antenna constructed on FR4-epoxy has $20{\times}15\;mm^2$ dimension. The measured results that are obtained return loss under -10 dB through 3.2~11.8 GHz without Wi-Fi bandwidth, a linear phase characteristic, a stable group delay, and omnidirectional radiation patterns are presented.