• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.40-44
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• 2006

This study investigated a new tuneable bandpass filter based on coplanar waveguide coupled line structure, and using the varactor diode for tuning the center frequency of the filter. The filter was designed by a commercial simulator and had a tuning range of 180[MHz] from 0.95[GHz] to 1.13[GHz]. The filter acceptable values regarding the insertion loss was less than 3[dB] and its return loss greater than 12[dB]. The figure of merit of the implemented tuneable filter increased with the reverse bias voltage up to 14[V] on the varactor diode. The proposed filter has a promising future as it can be used in integration processes and in various materials as substrate.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.968-971
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• 2001

In this paper, internal antennas for IMT-2000 handset(1.92∼2.17 GHz) were designed to be capable of being mounted on the circuit-board with a CPW(coplanar waveguide) feeding structure. The chip antennas were miniaturized to a greater extent by fabricating multilayer high dielectric ceramic($\varepsilon$$\sub$r/=7.8) hexahedron. The proposed antennas has λ/4 monopole element with helical structure in the multilayer dielectric ceramic hexahedron. The simulated and measured results were invesgated with width, length, and thickness of helical structure in the hexahedron.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.12
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• pp.1051-1057
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• 2000

A traveling-wave CPW(coplanar waveguide) electrode with abruptly broken input/output-taper for LiNbO$_3$optical modulator was designed and fabricated. The electrical characteristics of traveling-wave electrode on z-cut LiNbO$_3$crystal with SiO$_2$buffer layers were measured by network analyzer. To confirm the possibility of the electro-optic modulator electrode, detailed calculations of the impedance, microwave effective index and attenuation constants are presented as a function of the microwave electrode thickness, but the buffer layer thickness is fixed as 1${\mu}{\textrm}{m}$. These characteristics are discussed from the viewpoint of the device optimization and are expected to be design guides for the LiNbO$_3$modulator’s electrodes.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.524-527
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• 2003

In this paper, a new design for a Coplanar Waveguide (CPW) fed wide-band slot antenna is presented. To enhance the impedance bandwidth of the slot antenna, we proposed the tapering slot structure. A various resonance modes are generated in the tapering slot. The impedance bandwidth of the proposed antenna is about 12:1 ($2.0GHz{\sim}24.3GHz$) with $VSWR{\le}2$. Simulation results for return loss and radiation pattern are presented.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.72-76
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• 2008

In this paper, the several printed square loop antennas which modified monopole antennas are proposed. The proposed antennas are reduced about 20% physical size of antenna and miniaturized reactance value of impedance due to fold center part of the loop. They obtained omni-directional radiation patterns with broad bandwidth and feed method used coplanar waveguide to composed single planar. The proposed antenna bandwidth is about 900MHz($2.63{\sim}3.56GHz]$) resonance frequency on $VSWR{\le}2$. it can be sufficiency of S-DMB band.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.9
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• pp.12-20
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• 2013

In this paper, a co-planar waveguide(CPW) fed zeroth-order resonant(ZOR) antenna with frequency reconfigurable radiating structures is fabricated and measured. The unit cell of proposed antenna consists of a series metal-insulator-metal(MIM) capacitor and two shunt line inductors which are shorted through the via. The proposed antenna is designed based on a composite right/left-handed(CRLH) transmission line with two unit cells and it has open ended structure in order to radiate electromagnetic energy mainly on the shunt arm. In order to reduce the antenna size and to exhibit a frequency reconfigurable ability using diode switches four straight strips bent by 90 degrees are used as shunt inductors. The total size of fabricated antenna is $0.22{\lambda}_0{\times}0.16{\lambda}_0$ at zeroth-order resonant(ZOR) frequency. The measured maximum gain and bandwidth (VSWR ${\leq}2$) are 3.1 dBi and 56MHz at ZOR frequency of 2.97 GHz, respectively. This type of antenna can be applied to a frequency reconfigurable antenna system with triple bands.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1492-1497
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• 2017

In this paper, a design method for a CPW-fed wideband loop antenna for indoor digital TV applications is studied. The proposed loop antenna consists of a square loop and two circular sectors which connect the loop with central feed points, and the CPW feed line is inserted in the lower circular sector. The CPW feed line is designed to match with the 75 ohm port impedance for DTV applications, and the ground slots are etched in order to improve the impedance matching in the middle frequency region. The effects of the gap between the circular sectors and the location and dimension of the ground slots on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized antenna is fabricated on FR4 substrate, and the experiment results show that it operates in the frequency band of 463-1,280 MHz for a VSWR < 2, which assures the operation in the DTV band.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.11
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• pp.40-46
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• 2002

A MEMS(Micro Electro Mechanical System) package using a doped-silicon(Si) carrier for coplanar microwave and millimeter-wave integrated circuits is proposed in order to reduce parasitic problems of leakage, coupling and resonance. The proposed carrier scheme is verified by fabrication and measuring a GaAs CPW(Coplanar Waveguide) on the three types of Si-carriers(gold-plated high resistivity, lightly doped, high resistivity). The proposed MEMS package using the lightly doped(15 ${\Omega}{\cdot}$) Si-carrier shows parasitic-free performance since the lossy Si-carrier effectively absorbs and suppresses the resonant leakage.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.303-307
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• 2008

In this paper, a new co-planar waveguide ultra-wideband aperture is designed. The designed antenna consists of a rectangular aperture on a determined ground plane and a mushroom shaped stub. The mushroom-shaped stub, which is simple, convenient to analyze and optimise, has less parameter. This antenna has compact aperture size $21.1{\times}8.1mm^2$, designed on FR-4 substrate with dielectric constant of 4.3, thickness of l.5mm. CPW fed planar antenna has the advantages of wide-bandwidth, low-cost and easy interaction with the radio frequency front end circuitry.

• Korean Journal of Optics and Photonics
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• v.15 no.4
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• pp.375-384
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• 2004

Switching phenomenon of a three-waveguide optical coupler was analyzed by using the coupled mode theory, and the coupling-length of the device was calculated by means of the FDM. CPW traveling-wave electrodes were designed by the CMM and SOR simulation techniques so as to satisfy the conditions of phase-velocity and impedance matching. Traveling-wave modulators were fabricated on a z-cut LiNbO$_3$ substrate. Ti was in-diffused in LiNbO$_3$ to make waveguides and Au electrodes were built on the waveguides by the electroplating technique. Insertion loss and switching voltage of the optical modulator were about 4 ㏈ and 15.6V. Network analyzer was used to obtain S parameters and corresponding RF response. From the measurement, parameters of the traveling-wave electrodes were extracted as such Z$_{c}$=39.2 $\Omega$, Neff=2.48, and a0=0.0665/cm((GHz) (1/2)). The measured optical response R(w) was compared with the theoretically estimated and both responses were shown to agree well. The measurement results revealed that the ㏈ bandwidth turned out to be about 13 GHz.