• ETRI Journal
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• v.37 no.1
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• pp.21-25
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• 2015

A miniaturized triple-band antenna suitable for wireless USB dongle applications is proposed and investigated in this paper. The presented antenna, simply consisting of a circular-arc-shaped stub, an L-shaped stub, a microstrip feed line, and a rectangular ground plane has a compact size of $16mm{\times}38.5mm$ and is capable of generating three separate resonant modes with very good impedance matching. The measurement results show that the antenna has several impedance bandwidths for S11 ${\leq}$ -10 dB of 260 MHz (2.24 GHz to 2.5 GHz), 320 MHz (3.4 GHz to 3.72 GHz), and 990 MHz (5.1 GHz to 6.09 GHz), which can be applied to both 2.4/5.2/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. Moreover, nearly-omni-directional radiation patterns and stable gain across the operating bands can be obtained.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.5
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• pp.815-820
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• 2008

Recently the frequency assignment and the technical specifications of UWB systems for communications are completed. Therefore many UWB systems have been developed. In our country $3.1{\sim}4.8GHz$ and $7.2{\sim}10.2GHz$ are assigned for UWB systems for communications. When we consider RF technologies and the easy implementation of UWB systems, UWB systems used in the low band are more developed than high band systems. In this paper we design and implement a BPF for low band UWB systems by means of considering the easy implementation of UWB systems. The designed and implemented BPFs are low band filter and low band channel filters. The measured results of the low band filter show that the filter has 21.85dB and 17.91dB attenuation at 3.1GHz and 4.8GHz, 1.53GHz of -10dB bandwidth and 2dB of insertion loss. Low band can be divided into 3 channels with 500MHz of the channel bandwidth. The channel filter for channel number 1 has the characteristics of 24.85dB attenuation at 3.1GHz, 0.61GHz of -10dB bandwidth and 1.87dB of insertion loss. The filter for channel 3 in low band has 19.2dB of attenuation at 4.8GHz, 0.49GHz of -10dB bandwidth and 2.49dB of insertion loss.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.547-551
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• 2010

In this paper, Double rectangular patch with 4-bridges is investigated for solution of IEEE 802.11b/g(2.4GHz) and 802.11a(5.7GHz). Rectangular patch for 5.7GHz frequency band is printed on the PCB substrate and connected to another rectangular patch for 2.4GHz frequency band with 4-bridges to obtain dual band operation in a antenna element. The proposed antenna has a low profile and is fed by $50{\Omega}$ coaxial line. The dielectric constant of the designed antenna substrate is 3.27. Two rectangular patches have each resonance frequencies that are 2.4GHz and 5.7GHz. A dual-band characteristic is shown as connecting two rectangular patch using four bridges. Also, the proposed antenna is shown input return loss that is below -10dB at 2.4GHz and 5.7GHz of WLAN(Wireless LAN).

• 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.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.1-5
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• 2011

For measuring quad-band module system using WiBro network, frequency converter was developed. The size of the fabricated frequency converter is $3.1cm{\times}3.1cm{\times}0.4cm$. Noise figure of the receiver part of the frequency converter was 2.62 ~ 3.45 dB, EVM of that is -37.5 dB ~ -34.5 dB. And EVM of the transmission part was -42.5 ~ -35.5 dB. Quad-band module was fabricated with the developed frequency converter. Testing the quad-band module in 2.3 GHz WiBro network results the excellent internet connection for 2.5 GHz, 3.5 GHz and 5.5 GHz band.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.12
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• pp.718-728
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• 2014

The multi-band wireless local area network (WLAN) using 60 GHz band and the lower band (typically 2.4 GHz/5 GHz band) can support the very high data rate in short-distance communication using 60 GHz band and the long-distance communication using the lower band. For heightening the efficiency of multi-band WLAN, an band selection scheme is a necessity. In this paper, we propose an effective frequency band selection scheme for multi-band WLANs. By using computer simulation with NS-3, we show the performance of the proposed schemes when the stations suffer from the human blockage and the log-normal shadowing.

• 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.

• Journal of Advanced Navigation Technology
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• v.22 no.1
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• pp.31-36
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• 2018

In this paper, we designed and implemented an ultra wideband(UWB) antenna with band rejection characteristics. The proposed antenna consists of a planar radiation patch with slots and ground planes on both sides. Due to the slots in the radiation patch, the antenna shows band rejection characteristics. U-type slot contributes for wireless local area network(WLAN, 5.15~5.825 GHz) band rejection and n-type slot contributes for X-Band(7.25~8.395 GHz) band rejection. To make voltage standing wave ratio(VSWR) less than 2.0 for UWB frequency band except rejection bands, the shapes of planar radiation patch and ground plane was modified. The Ansoft 's high frequency structure simulator(HFSS) was used for the design process and simulations of the proposed antenna. The simulated antenna showed VSWR less than 2.0 for all UWB band excepts for dual rejection bands of 5.15 ~ 5.94 GHz and 7.02 ~ 8.45 GHz. And measured VSWR for the implemented antenna is less than 2.0 for all UWB band of 3.10~10.60 GHz excluding dual rejection bands of 5.12~5.95 GHz and 7.20~8.58 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2526-2533
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• 2015

In this paper, a design method for a compact dual-band coplanar waveguide-fed slot antenna using SRR(split-ring resonator) conductor is studied. The SRR conductor is loaded inside a rectangular slot of the proposed antenna for dual-band operation. When the SRR conductor is inserted into the slot, the original rectangular slot is divided into a rectangular loop region and a rectangular slot region, and frequency bands are created by the loop and slot, separately. A prototype of the proposed dual-band slot antenna operating at 2.45 GHz WLAN band and 3.40-5.35 GHz band is fabricated on an FR4 substrate with a dimension of 30 mm by 30 mm. Experiment results show that the antenna has a desired impedance characteristic with a frequency band of 2.38-2.51 GHz and 3.32-5.38 GHz for a voltage standing wave < 2, and measured gain is 1.7 dBi at 2.45 GHz, and it ranges 2.4-3.2 dBi in the second band.

• Journal of Advanced Navigation Technology
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• v.13 no.5
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• pp.714-719
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• 2009

In this paper, a compact antenna with band-rejected characteristic for Ultra-Wideband(UWB) applications is proposed. The designed antenna not only shows sufficient impedance bandwidth but has band-rejected characteristic for the frequency band of 5.15~5.825GHz limited by IEEE 802.11a and HIPERLAN/2. To obtain both properties of wideband band rejection, the techniques of a partial ground plane and embedded thin U-slot into planar radiator are used respectively. A designed antenna satisfied a VSWR less than 2:1 for the frequency band of 3.1~10.3GHz with band rejection of 4.90~5.92GHz.