• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.424-429
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• 2016

This paper presents dual-mode ring-resonator bandpass filter using LUC of artificial-transmission-lines. The conventional ring-resonator bandpass filter has limitation in miniaturization because the conventional ring-resonator is based on a one wavelength operation, and problem due to undesire harmonics. The ring-resonator bandpass filter is miniaturized and show higher order mode rejection by configuring a ring-resonator with LUC of artificial-transmission-lines. The two-stage bandpass filter is designed and fabricated with a ring-resonator and input/output interdigital coupled line. A fabricated filter shows dual-mode, rejection of whole ultra wide band, sharp skirt characteristics and has ring area reduced by 60 % compared to the conventional ring-resonator bandpass filter.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.810-813
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• 2003

Application of inorganic silica-neodymia alloy films grown by sputtering technology to the dielectric layer of plasma display panel (PDP) is presented. The experimental results reveal that dielectric constant of the alloy films increases with neodymia concentration. Also, the alloy films act as band rejection color filter owing to sharp absorptions originating in the intratransition within the 4f shell of the $Nd^{3+}$ ion. In the optical band pass region, the transmittances of the alloy films show higher than those of commercial glass-like dielectrics. As a result, the luminance of PDP device with the alloy dielectric layer is higher than that of device with conventional dielectrics, indicating wider color gamut and higher color purity.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.45-46
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• 2006

An ultrawide bandpass filter with sharp rejection and wider stopband is designed and implemented using multilayer ceramic configuration. The proposed filter is composed of a broadside coupled structure and a ring type filter with an embedded stripline stub. The measured results show that the fractional bandwidth and upper stopband of the proposed filter are 106 % and better than -30 dB, respectively. The insertion loss is less than 1 dB, and group delay is less than 0.3 ns in the passband. In addition, ring and broadside coupled gap structures are characterized and compared to the proposed structure.

• Journal of Navigation and Port Research
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• v.30 no.7
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• pp.607-610
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• 2006

A new compact microstrip low-pass filter and its equivalent-circuit model are developed. The philosophy of the structure behind this novel microstrip low-pass filter is simple as it is composed of a pair of symmetrical parallel coupled-line and an open-stub. With this configuration, a finite attenuation pole near the stopband cutoff frequency is available and adjustable by simply tuning the circuit parameters. Furthermore, the rejection bandwidth of this type of low-pass filter can be extended. In order to validate the feasibility of the proposed design method, a low-pass filter based on a microstrip structure is designed, fabricated, and measured. Experimental results agree very well with the simulation and analytical results.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2383-2385
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• 2005

In this paper we discuss the design and fabrication of two millimeter wave filters, in bandpass and bandstop topologies for wireless communications applications. The filters are made using a high Q MMIC transmission line, which consists of a 100 micrometers tall, surface micromachined, air filled inverted microstrip structure on a quartz substrate, made by using a JSR THB-151N negative photoresist sacrificial layer mold and electroplating technology. The filter topologies include a new, very compact, four pole, cross-coupled filter, that presents a single transmission zero at the lower side of the passband, which provides a very sharp out of passband rejection at this region.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.92-98
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• 2010

A new wideband bandstop filter(BSF) with a sharp roll-off characteristic is introduced in a stripline structure in this paper. The BSF consists of two sections: the first is two capacitively coupled $\lambda/4$ short-circuited lines with opposite ground positions, while the second is a capacitively coupled $\lambda/4$ short-circuited line. The BSF provides three transmission zeros within the stopband and better than 22 dB rejection over the whole wireless local area network (WLAN) band from 5.15 to 5.825 GHz. The BSF, cascaded to an U.S. ultra-wideband(UWB: 3.1~10.6 GHz) band-pass filter(BPF), is simulated with HFSS and realized with low-temperature co-fired ceramic(LTCC) green tape with a dielectric constant of 7.8. The measurement results agree well with the HFSS simulation results. The size of the UWB BPF including the BSF is $3{\times}6.3\times0.45\;mm^3$.

• Membrane and Water Treatment
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• v.11 no.2
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• pp.111-121
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• 2020

The fouling of Nanofiltration membrane (NF) was examined using wastewater containing reactive black dye RB5 of 1500 Pt/Co color concentrations with 16890 mg/l TDS collected from El-alamia Company for Dying and Weaving in Egypt. The NF-unit was operated at constant pressure of 10 bars, temperature of 25℃, and flowrate of 420 L/min. SEM, EDX, and FTIR were used for fouling characterization. Using the ROIFA-4 program, the total inorganic fouling load was 1.07 mM/kg present as 49.3% Carbonates, 10.1% Sulfates, 37.2% Silicates, 37.2% Phosphates, and 0.93% Iron oxides. The permeate flux, recovery, salt rejection and mass transfer coefficients of the dye molecules were reduced significantly after fouling. The results clearly demonstrate that the fouling had detrimental effect on membrane performance in dye removal, as indicated by a sharp decrease in permeate flux and dye recovery 68%. The dye mass transfer coefficient was dropped dramatically by 34%, and the salt permeability increased by 14%. In this study, all the properties of the membrane used and the fouling that caused its poor condition are identified. Another study was conducted to regeneration fouled membrane again by chemical methods in another article (Abdel-Fatah et al. 2017).

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.77-80
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• 2008

In this paper, low phase noise VCO using novel compact microstrip spiral resonator is proposed. A spiral resonator has super compact dimension, low insertion losses in the passband and high level of rejection in the stopband with sharp cutoff and a large coupling coefficient value, which makes a high Q value, and has reduced the phase noise. To increase the tuning range of VCO, varactor diode has been connected at the tunable negative resistance in VCO. This VCO has presented the oscillation frequency of $5.686{\sim}5.841GHz$, harmonics -29.83 dBc and phase noise of $-115.16{\sim}-115.17dBc/Hz$ at the offset frequency of 100 KHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.1
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• pp.28-35
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• 2010

In this paper, we designed and fabricated a ultra-wideband(UWB) bandpass filter with a good performance of a stopband, and a notched band in passband. The transformed equivalent circuit of the highpass filter was realized by distributed element. A wide-passband with 3-dB fractional bandwidth of more than 100 % was achieved by using optimum response of the HPF. For improving lower and upper stopband characteristic, a cross coupling between feed lines was employed, which was analyzed by desegmentation technique. In order to reject interference of Wireless LAN and Hyper LAN(5.15~5.825 GHz), the narrow notched(rejection) band was realized by a spurline. The fabricated BPF indicated the passband from 3.1 to 10.55 GHz and the flat group delay of less than 0.94 ns over the entire passband except the rejection band. The filter shown sharp attenuation both inside and outside the band and notched band from 5.2 to 6.12 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.511-516
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• 2006

In this raper, we propose the Sequentiel Couleur Avec Memoire or Sequential Color with Memory (SECAM) video encoder system using modified anti-cloche filters and the SECAM video decoder system using a band pass filter (BPF) and an error-free square root. The SECAM encoder requires an anti-cloche filter recommended by International Telecommunication Union-Recommendation (ITU-R) Broadcasting service Television (BT) 470. However, the design of the anti-cloche filter is difficult because the frequency response of the anti-cloche filter is very sharp around rejection-frequency area. So, we convert the filter into a hish pass filter (HPF) by shifting the rejection frequency of 4.286MHz to 0Hz frequency. The design of HPF becomes very easy, compared to that of the anti-cloche filter. The proposed decoder also uses an error-free square root, two differentiators and trigonometric functions to extract color-component information of Db and Dr accurately from frequency modulation (FM) signals in SECAM systems. Also, the BPF in decoder it used for removing color noise in chrominance and dividing CVBS into chrominance and luminance. The proposed systems are experimentally demonstrated with Altera FPGA APEX20KE EP20K1000EBC652-3 device and TV sets.