• Journal of the Microelectronics and Packaging Society
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• v.27 no.4
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• pp.67-75
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• 2020

In this paper, by applying LCP substrate, the capacitor and inductor are implemented with a variety of value that can be used in 35 GHz circuits. Depending on how to apply it to the circuit, it is required high value by designing the basic structures such as electrode capacitor and spiral inductor. However they are not available in high-frequency domain, because their SRF(Self-Resonant Frequency) is lower than the frequency of 35-GHz. By finding the limit, this paper devised classifying passive devices for the DC and the high-frequency domain. The basic structure is suitable for DC and microstrip λ/8 length stub structure can be used for high-frequency. The open and short stub structure operate as a capacitor and inductor respectively in the frequency of 35 GHz. If their impedance is known, it is possible to extract the value through the impedance-related equation. By producing with the permittivity 2.9 LCP substrate, the basic structure which are available in the DC constituted a library of capacitance of 1.12 to 13.9 pF and inductance of 0.96 to 4.69 nH, measured respectively. The stub structure available in the high-frequency domain were built libraries of capacitance of 0.07 to 2.88 pF and inductance of 0.34 to 1.27 nH, calculated respectively. The measurements have proven how to diversify value, so libraries can be built more variously. It is possible to integrate with the operation circuit of TRM(Transmit-Receive Module) for the frequency 35-GHz, it will be an alternative to the passive devices that can be properly utilized in the circuit.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.307-308
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• 2006

In this paper, we propose an ultra wideband pass filter of ring type with embedded stripline stub. The fractional bandwidth was 98 % at the center frequency of 8 GHz and insertion loss was below 1 dB in passband. Two kinds of dielectric materials with the permittivity of 7.8 and 40, respectively were adopted in evaluating the suggested filter structure. As the permittivity of material became larger, the size of filter smaller as expected without any sacrifice in filter performance. In summary, the suggested filter structure has smaller size due to the embedded stripline stub and can be minimized by adopting dielectric material with higher permittivity again.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.125-131
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• 2007

An iterative Green's function method (IGFM) is introduced in order to analyze complex electromagnetic waveguide stub structures in view of a university student. The IGFM utilizes a Green's function approach and an regional iteration scheme. A physical iteration mechanism with simple mathematical equations facilitates clear formulations of the IGFM. Scattering characteristics of a standard E-plane T-junction stub in a parallel-plate waveguide are theoretically investigated in terms of the IGFM. Numerical computations illustrate the characteristics of reflection and transmission powers versus frequency.

• Journal of electromagnetic engineering and science
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• v.14 no.4
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• pp.387-392
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• 2014

In this paper, a size-reduced Wilkinson balun with wide harmonic-suppressed band is presented. An accurate analysis of the parallel coupled line with an open stub (PCL-OS) is carried out. The PCL-OS structure shows excellent low pass filter and harmonic-suppression characteristics, which is useful for designing a low pass filter unit cell (LUC) with a reduced size. The designed Wilkinson balun at a 2.45 GHz center frequency not only shows an excellent harmonic suppression including the 5th harmonics up to 14 GHz over 15 dB, but it also has an area reduced to 48% of the conventional one.

• Journal of electromagnetic engineering and science
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• v.16 no.2
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• pp.100-105
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• 2016

We have designed a three-channel output multiplexer (OMUX) using a band-pass filter and an ultra-wideband (UWB) antenna. The proposed band-pass filter is composed of an inner rectangular loop, an outer open stub, and a defected ground structure. The outer open stub can be used to control the pass band, and the inner rectangular loop can improve the insertion loss characteristics of the band-pass filter. The proposed band-pass filter, UWB antenna, and OMUX are fabricated and measured. The designed OMUX can cover the band group 1 (3,168-4,752 MHz) of WiX system. The measured radiation patterns are close to those of a conventional dipole antenna and the measured antenna gain varies from 1.8 dBi to 3 dBi over the operating frequency range.

• Steel and Composite Structures
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• v.47 no.5
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• pp.645-661
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• 2023

Concrete-filled steel tubular columns with double inner steel tubes (CFST-DIST) are a novel type of composite members developed from conventional concrete-filled steel tubular (CFST) columns. This paper investigates the structural performance of circular CFST-DIST stub columns using nonlinear finite element (FE) analysis. A numerical model was developed and verified against existing experimental test results. The validated model was then used to compare circular CFST-DIST stub columns' behavior with their concrete-filled double skin steel tubular (CFDST) and CFST counterparts. A parametric study was performed to ascertain the effects of geometric and material properties on the axial performance of CFST-DISTs. The FE results and the available test data were used to assess the accuracy of the European and American design regulations in predicting the axial compressive capacity of circular CFST-DIST stub columns. Finally, a new design model was recommended for estimating the compressive capacity of CFST-DISTs. Results clarified that circular CFST-DIST columns had the advantages of their CFST counterparts but with better ductility and strength-to-weight ratio. Besides, the investigated design codes led to conservative predictions of the compressive capacity of circular CFST-DIST columns.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.12
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• pp.55-67
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• 2010

The electrical properties of a back drilled via-hole (BDH) without the open-stub and the plated through via-hole (PTH) with the open-stub, which is called the conventional structure, in a high-count multi~layered (HCML) printed circuit board (PCB) were investigated for a high-speed digital system, and a selected inner layer to transmit a high-speed signal was farthest away from the side to mount the component. Within 10 GHz of the broadband frequency, a design of experiment (DOE) methodology was carried out with three cause factors of each via-hole structure, which were the distance between the via-holes, the dimensions of drilling pad and the anti-pad in the ground plane, and then the relation between cause and result factors which were the maximum return loss, the half-power frequency, and the minimum insertion loss was analyzed. Subsequently, the empirical formulae resulting in a macro model were extracted and compared with the experiment results. Even, out of the cause range, the calculated results obtained from the macro model can be also matched with the measured results within 5 % of the error.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.1-5
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• 2017

In this paper, we propose a wideband band-stop filter (BSF) in order to extend the stopband of the band-stop filter using a symmetric dual spurline and the coupled open stub. First, we know that the symmetric dual spurline structure is advantageous in widening the stopband, as compared to the asymmetric dual spurline structure. So we designed a band-stop filter that combines the electrically coupled open stub (ECOS) band-stop filter with a symmetric dual spurline. We can greatly extend the stopband, when it is combined with the dual spurline and electrically coupled open stub on a microstrip transmission line, without any size increment. The stopband of the proposed band-stop filter is extended by approximately 244% (rejection depth: -20 dB) compared with a band-stop filter without a dual spurline.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.4
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• pp.35-40
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• 2022

This paper proposes an antenna that is located outside the PCB substrate of an electronic product to enable wireless communication in the ISM band. The PCB designed the T-shaped OPEN-STUB power supply line to be miniaturized so that it does not interfere with parts or interfere with design. The characteristics of the antenna were confirmed in the 2.4GHz and 5.8GHz bands using a T-shaped stub feeder and a spiral structure. The size of the antenna is 5mm in width × 6.5mm in length, and the thickness of the PCB is 1.2T. As a result of measurement of the manufactured antenna, it was possible to obtain a return loss of -10dB or more at 2.4GHz and 5.8GHz. In the E-plane, the gain was -4.45 dBi, and in the H-plane, the gain was -1.05 dBi. Therefore, the proposed small antenna for wireless communication showed excellent performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.7
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• pp.1237-1242
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• 2016

In this paper, the low pass filter with harmonics suppression and rejection using parallel coupled-line and radial type open stub is presented. And the resultant characteristic of the proposed low pass filter is that the harmonics are suppressed and rejected in wide bandwidth due to the parallel coupled-line structure. The open stub of a low pass filter is constructed in radial type which can be used to adjust the size of filter. The size of the proposed low pass filter is $6.98{\times}7.60mm2$ and the cut off frequency is 2.45 GHz. And the filter is economical in unit cost and can be constructed easily and has the merit of mass product because the filter is composed of distributed element. Also, the widely rejected harmonics is 128 % in the bandwidth and the insertion and return losses of the low pass filter are 1.07 dB and 19.5 dB, respectively.