• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.15-22
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• 2018

In this paper, a microstrip-fed triple-band monopole antenna for WLAN/WiMAX applications was proposed. The proposed antenna is consist of two arc-shaped and one strip line structure, then get the three current path and then designed in order to get triple resonant characteristics. We carried out simulation about parameters. Taking account of coupling effect, Adjusted the length of the two arc-shaped and one strip line, we get the optimized parameters. The proposed antenna is fabricated on an FR-4 substrate, the dielectric constant is 4.4, and total size is $23.5mm(W1){\times}32.0mm(L1){\times}1.0mm(t)$, and its proposed antenna size is $21.0mm(W6){\times}31.0mm(L7)$. From the measured results, return loss of the proposed antenna satisfied return loss 927 MHz (1.844~2.771 GHz), 926 MHz (3.33~4.256 GHz), and 1,415 MHz (5.13~6.545 GHz). And measured results of gain and radiation patterns displayed for operating bands.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.4
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• pp.69-76
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• 2005

In this paper, a 2 stage 6-pole bandpass filter(BPF) is designed and implemented by using triple-mode cavity for satellite payload system. The BPF has a 100MHz bandwidth at the center frequency of 14.5GHz(Ku-band) and the response of the filter is the Chebyshev function. The cavity filter uses two orthogonal $TM_{113}$ modes and one $TM_{012}$ mode. The coupling between the adjacent cavityes(intercavity coupling) results in a Chebyshev response and is accomplished by only H-filed component of If modes. The size and location of intercavity slot is determined by the coupling equation from E-and H-field of TE and TM resonant modes in circular cavity. The 2-stage 6-pole triple-mode cavity BPF has the insertion loss of 2.4dB and the reflection loss of 15dB in the passband. The triple-mode BPF proposed in this thesis can be used as channel filters for satellite payload system and can minimize filter assembly in general wireless communication system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.4
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• pp.679-687
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• 2017

In this paper, a microstrip-fed triple-band monopole antenna with DGS (Defected Ground Structure) for WLAN/WiMAX applications was proposed. 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 triple band characteristics. We carried out simulation about parameters. Adjusted the position and length of the two strips and three slits, we get the optimized parameters. The proposed antenna is fabricated on an FR-4 substrate of which the dielectric constant is 4.4, and its overall size is $34mm(W_1){\times}34mm(L_1){\times}1.6mm(t)$, and its proposed antenna size is $17.0mm(W_6){\times}30.75mm(L_3+L_4+L_9)$. From the fabricated and measured results, return loss of the proposed antenna satisfied return loss -10dB bandwidth 360 MHz (2.335~2.695 GHz), 645 MHz (3.37~4.015 GHz) and 1,770 MHz (5.14~6.91 GHz). And measured results of gain and radiation patterns characteristics displayed for operating bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.320-327
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• 2012

In this paper, a novel ultra wide band(UWB) antenna with tri-band notch capability is proposed. The proposed antenna can reject WiMAX(3.3~3.7 GHz), WLAN IEEE 802.11a/n(5.15~5.825 GHz), and ITU(8.025~8.4 GHz) bands. Band rejection capability is achieved only split ring resonators(SRRs) and complementary SRRs(CSRRs). The SRR under the radiating patch, the CSRR loaded on the radiating patch, and the CSRRs on the ground of the CPW feeding reject the WiMAX, WLAN, and ITU bands, respectively. The simulation and measurement results demonstrate the performances of the proposed antenna.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.433-439
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• 2012

In this paper, we proposed the triplexer using unit-cell of CRLH transmission line which has a bandpass characteristic to reduce adjacent channel interference. The input impedance of triplexer with each channel filter is operated open-circuit at the resonance frequencies of other channels. Such property is due to the combination a series and parallel resonance circuits of CRLH-TL unit-cell. The measured triplexer results are showed a measured insertion loss of each channel, less than 1.5 dB, matching at each port, less than 15dB and isolation between channel, better than 25 dB. Also, to validate the triplexer, a small signal amplifier with triple-band is designed and tested. the measured amplifier results show good agreements with prediction.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.73-78
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• 2007

In this paper, the CPW-fed triple-band internal planar monopole antenna which simultaneously meets the three bands such as Cellular, PCS and Wibro is designed. The size of the radiation elements can be reduced to about $\lambda/4$ by designing the CPW-fed monopole antenna and then we can miniaturize the antenna size by meandering the radiation elements. In addition, we design the planar antenna for the slim-type mobile phone. We can obtain the desired antenna properties by controlling the length of each radiation elements. The measured return loss of the antenna is less than -7 dB at the desired bandwidth. And the measured radiation patterns are similar to that of the monopole antenna. The designed antenna has the gains -5.2 dBi. -2 dBi, -0.4 dBi at each resonant frequencies respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.10
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• pp.1060-1070
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• 2003

The frequency selective surface for use in Ka/Ku band parabolic antenna of domestic satellite communications is proposed. The frequency selective surface structure consists of the infinite periodic arrays of the triple square loop slot element with narrow width on the honeycomb structure of multi-layered dielectric. The frequency selective surface is fabricated and measured. The good agreement is obtained between theory and experiment. It is demonstrated that the frequency selective surface passes 14/12 GHz band wave while reflecting 30/20 GHz band wave as required.

• Journal of Advanced Navigation Technology
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• v.25 no.6
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• pp.536-542
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• 2021

In this paper, we proposed a triple band printed monopole antenna with a bent branch strips for WiFi / 5G. An antenna structure in which bent strips for generating multiple resonance are attached in the form of branches was newly proposed based on a typical monopole strip vertically erected as a triple band antenna structure. The proposed antenna is designed on a FR-4 substrate with dielectric constant 4.3, thickness of 1.6 mm, and size of 28×40 mm². The measured impedance bandwidth is 430 MHz (2.22~2.65 GHz) in the 2.4 GHz WLAN, 450 MHz (3.38~3.83 GHz) in the 3.5 GHz and 2390 MHz (4.95~7.34 GHz), In particular, it has been observed that antenna has a stable omnidirectional radiation patterns as well as gain of 1.537 dBi, 1.878 dBi and 2.337 dBi in the entire frequency band of interest.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.4
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• pp.447-452
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• 2011

In this paper, we present a compact triple-mode resonator. The resonator itself can provide three transmission poles and one transmission zero. The resonance condition of each mode is analyzed theoretically, and the transmission zero is generated by open stub. Using this proposed resonator, a compact three pole bandpass filter for 2.4 GHz WLAN application with one transmission zero is designed and fabricated. The fabricated triple-mode filter shows 3 dB bandwidth of 15.8 % with the center frequency 2.4 GHz and less then 1.17 dB in 2.4~2.5 GHz passband. The size of fabricated triple-mode filter including the feed lines is 15.9 mm${\times}$9.7 mm and very compact compared with previous reported triple-mode filter.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.1
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• pp.30-38
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• 2015

In this paper, the design of a compact triple-mode bandpass filter using a high-Q cylindrical dielectric resonator is proposed. In detail, the triple $TE_{01{\delta}}$ modes along three orthogonal axes are used and novel coupling structure in the metallic enclosure is adopted to introduce the coupling between the resonant modes. Due to the cross coupling, the proposed bandpass filter has an asymmetric frequency response with flexible three transmission zeros, one of which can be located very close to the passband edge to provide an extremely sharp skirt characteristic with low insertion loss. The proposed filter is about 60 % miniaturized compared with conventional single-mode dielectric resonator filter. The proposed bandpass filter design is validated by the circuit and 3D EM simulations and measurements compared to the target specifications.