• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.45-51
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• 2015

In this paper, we study the RF characteristics of the short wavelength thin-film transmission line employing microstrip line (ML)/coplanar waveguide (CPW) composite structure on silicon substrate for application to RFIC (radio frequency integrated circuit). The thin-film transmission line employing ML/CPW composite structure showed a wavelength shorter than conventional transmission lines. Concretely, at 10 GHz, the wavelength of the transmission line employing ML/CPW composite structure was 6.26 mm, which was 60.5 % of the conventional coplanar waveguide. We also extracted the bandwidth characteristic of the transmission line employing ML/CPW composite structure using equivalent circuit analysis. The S parameter of the equivalent circuit showed a good agreement with measured result. According to the bandwidth extraction result, the cut-off frequency of thin-film transmission line employing ML/CPW composite structure was 377 GHz. Above results indicate that the transmission line employing ML/CPW composite structure can be effectively used for application to broadband and compact RFIC.

• 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.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.107-115
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• 2005

This paper presents the structure of a broadband coplanar waveguide(CPW) fed square slot antenna with a impedance bandwidth tuning patch. The designing method of the antenna suggests that two resonant frequencies are excited as a dual-frequency dipole antenna following the dimensions of the square slot. In other words, the lower resonant frequency mainly depends on the slot width and the higher one its length. A CPW fed square slot antenna with a impedance tuning patch was measured to $20GHz^\~33GHz$, $50\%$, VSWR=2 impedance bandwidth by adjusting the dimensions of the tuning patch when the slot length had $70\%$ of its width. This result shows that a medical CPW fed antenna is easily implemented with a simple square slot structure including a bandwidth tuning patch in the center.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.11
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• pp.2518-2525
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• 2015

In this paper, we propose a UWB(Ultra Wide Band) antenna with CPW(Coplanar Waveguide) structure notched the 802.11a(5.15 ~ 5.825 GHz) band by using the U shaped slot. The proposed antenna not only shows Ultra-Wideband characteristic(3.1 ~ 10.6 GHz) suitable for UWB communications but has partially notched-band characteristic to reject 5 GHz WLAN band(5.15 ~ 5.825 GHz). The antenna is designed on an FR-4 substrate of which the dielectric constant is 4.4, and its overall size is $30mm(W){\times}20mm(L){\times}1mm(t)$. Fabricated antenna satisfied $VSWR{\leq}2$ in 3.1 ~ 10.6 GHz except for the band rejection of 5.15 ~ 5.825 GHz. And measured results of gain and radiation patterns characteristics displayed determined for operating bands.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1143-1148
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• 2003

The distortion of picosecond pulses caused by dispersion as it propagates along microstripline and CPW(Coplanar waveguide) is investigated and measured using time domain measurement. Especially, this study presents that the distortion of these lines is analyzed and compared considering the relation between the dispersion effect and cut-off frequency(f$\_$TE/) of fundamental TE mode for the substrate of line. To verify theoretical results, several samples of 50 $\Omega$ lines are fabricated on the two kind of substrates with the different values of f$\_$TE/. The propagation characteristics of picosecond Gaussian pulse on thess lines are simply measured using VNA(Vector Network Analyzer) with the time-domain analysis function.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1248-1253
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• 2008

The MCS(Micro-Coplanar Strip) line with ground has been analyzed. The conformal mapping method is used to calculate the quasi-static effective dielectric constant and characteristic impedance of this MCS line. The computed results of the present work are found to be in good agreement when compared with the results obtained using commercial S/W, IE3D. And in this paper, the stepped-impedance low pass filter is designed and fabricated with MCS lines for improving the frequency responses. The LPF proposed structure has been also designed and implemented to have the sharp attenuation characteristics in stop band. The agreement between simulation and measurement results verify the implemented LPF.

• Journal of the Korean Ceramic Society
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• v.43 no.2 s.285
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• pp.74-78
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• 2006

A non-integrated type noise filter on a Coplanar Waveguide (CPW) transmission line is demonstrated by using a highly resistive $Co_{41}Fe_{38}Al_{13}O_8$ nanogranular thin film with the dimensions of $4\;mm (\iota)\times4\;mm(\omega)\times0.1\;{\mu}m(t)$. The noise suppression characteristics are evaluated without placing an insulating layer between the CPW line and the magnetic thin film. The insertion loss is very low being less than 0.3 dB and this low value is maintained up to 2 GHz. At a ferromagnetic resonance frequency of 3.3 GHz, the power loss is very large and the degree of noise attenuation is measured to be 3 dB. This level of noise attenuation is still small for real applications; however, considering the small magnetic volume used in this work, further improvement is expected by simply increasing the magnetic volume and by integrating the magnetic thin film into the CPW transmission line.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.7
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• pp.761-767
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• 2012

In this paper, a novel ultra-wideband planar monopole antenna for the UHF communications and Digital-TV reception is proposed. The proposed antenna fed by a coplanar waveguide(CPW) is based on a triangular patch that has a broadband characteristic. To further increase the bandwidth of the triangular patch antenna, the top side of the regular triangular patch is loaded with a notch cut and each oblique side with a step. In addition, a slope is given to the ground plane of the CPW structure. Experimental results show that the -10 dB return loss bandwidth of the proposed antenna is 2,320 MHz from 480~2,800 MHz(5.83:1 bandwidth), which covers all the frequency bands of the various wireless communication systems and Digital TV broadcasting in the UHF band. Within the entire operating frequency range, the measured antenna gain in y-z plane(E-plane) varies from 3.01 to 4.71 dBi.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.59-60
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• 2017

In this paper, we studied a design method for obtaining broadband property by loading a chip capacitor on a coplanar waveguide(CPW)-fed compact quasi-Yagi antenna(QYA). The proposed antenna is a three-element QYA with dipole, reflector, and director. To reduce the size, the ends of both dipole and reflector are bent, and balun is incorporated in the antenna. To improve impedance matching, the loading position and capacitance value of chip capacitor were determined. From some simulations, the proposed antenna using an FR4 substrate with a size of 90 mm by 90 mm was designed for the operation in a broadband covering the UHF RFID and GPS systems. The antenna showed a good performance with a broadband of 850-1,626 MHz(62.7%) for a VSWR ${\leq}2$, a gain ${\geq}3dBi$, and a frong-to-back ratio ${\geq}4.6dB$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.212-216
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• 2004

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 measured impedance bandwidth of the proposed antenna is about 13:1(2.0 GHz∼25.9 GHz) with VSWR$\leq$2. Simulation and measurement results for return loss and radiation pattern are presented.