• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5A
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• pp.482-489
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• 2010

In this paper we have proposed a new architecture of DQ-IRM(Double-Quadrature Image Rejection Mixer) for image rejection in the low-IF receiver. It consist of a frequency-tunable RF PPF(Poly Phase Filter) and the quadrature mixers. The conventional DQ-IRM generates the quadrature RF signals for the RF wide band at once. But the proposed DQ-IRM with the frequency-tuable RF PPF generates the quadrature RF signals for the narrow band of 2~3 channels bandwidth, which is partitioned from the RF wide band. We designed the CMOS RF tuner for T-DMB(Terrestrial Digital Multimedia Broadcasting) with the proposed 3rd DQ-IRM using a 0.18um CMOS technology and verified the performances of the designed receiver such as the image rejection ratio, the noise figure and the power consumption. The overall NF of the RF tuner is about 1.26 dB and the image reject ratio is about 51 dB. The power consumption is 55.8 mW at 1.8 V supply voltage. The chip area is $3.0{\times}2.5mm^2$.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.225-227
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• 2009

International standard specification, H.264/SVC improved from H.264/AVC, is set up so as to promote free use of huge multimedia data in various channel environments.;H.264/AVC is a international standard speicification for video compression, adopted and commercialized as standard for DMB broadcasting by JVT of ISO/IEC MPEG and ITU-T VCEG. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding. Among prediction technologies, 'inter-layer intra prediction' is to use co-located block of up sampled sublevels as a prediction signal. At this time, application of interpolation is one of the most important factors to determine encoding efficiency. SVC's currently using poly-phase FIR filter of 4-tap and 2-tap respectively to luma components. This paper is written for the purpose of analyzing encoding performance according to the interpolation. For this purpose, we applied poly-phase FIR filter of '2-tap', '4-tap' and '6-tap' respectively to luma components and then measured bit-rate, PNSR and running time of interpolation filter. We're expecting that the analysis results of this paper will be utilized for effective application of interpolation filter. SVC standard uses 'intra/inter prediction' in AVC as well as 'inter-layer intra prediction', 'inter-layer motion prediction' and 'inter-layer residual prediction' to improve efficiency of encoding.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.514-517
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• 1998

This paper proposed a symmetric feedback current enhancement circuit with 1.5V power supply to design a 3$^{rd}$ order butterworth low pass filter. The proposed filter designed on 0.8.mu.m CMOS n-well double poly/double metal process simulated in HSPICE composed of the 3dB frequency enhancement circuit and the unity-gain frequency enhancement circuit. The simulation result on the design filter shows the badnwith of 25MHz, phase of 92.6 .deg. and power consumption of 0.3mW..

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2479-2484
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• 2018

The filter bank multicarrier modulation (FBMC) technique is one of multicarrier modulation technique (MCM), which is mainly used to improve channel capacity of cognitive radio (CR) network and frequency spectrum access technique. The existing FBMC System contains serial to parallel converter, normal QAM modulation, Radix2 inverse FFT, parallel to serial converter and poly phase filter. It needs high area, delay and power consumption. To further reduce the area, delay and power of FBMC structure, a new clock gating technique is applied in the QAM modulation, radix2 multipath delay commutator (R2MDC) based inverse FFT and unified addition and subtraction (UAS) based FIR filter with parallel asynchronous self time adder (PASTA). The clock gating technique is mainly used to reduce the unwanted clock switching activity. The clock gating is nothing but clock signal of flip-flops is controlled by gate (i.e.) AND gate. Hence speed is high and power consumption is low. The comparison between existing QAM and proposed QAM with clock gating technique is carried out to analyze the results. Conversely, the proposed inverse R2MDC FFT with clock gating technique is compared with the existing radix2 inverse FFT. Also the comparison between existing poly phase filter and proposed UAS based FIR filter with PASTA adder is carried out to analyze the performance, area and power consumption individually. The proposed FBMC with clock gating technique offers low power and high speed than the existing FBMC structures.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.2
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• pp.130-135
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• 2009

In this paper, an efficient pulse-shaping filter structure for high-density and low-power electronic devices is proposed. The proposed structure is based on polyphase decomposition property and look-up table method. By Synopsys CAD simulations, it is shown that the use of the proposed method can result in reduction in the number of gates by 54% and can reduce power consumption by 9%.

• The Journal of the Acoustical Society of Korea
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• v.16 no.6
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• pp.54-60
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• 1997

In the SC filter consist of SC integrator and SC Lossy Integrator, after this paper proposes the method that cancels phase error using LDI clock and the imaginary part in damping term of SC Lossy integrator, LDI fifth order elliptic low-pass SC filter is designed. With the result of SCANAP program simulation applying the designed CMOS OP-Amp using power supply ${\pm}$5V and MOSIS 2--${\mu}$m double-poly double-metal n-well CMOS design rule.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.10
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• pp.1935-1940
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• 2016

This paper proposes a phase-locked loop (PLL) to minimize the loop filter output voltage fluctuation by using a comparator including RC time constant circuits. The voltage variation of loop filter is inputted to RC time constant circuits which have two RC time constants, large and small. While a small RC time constant circuit quickly conveys the output voltage variation of loop filter, a large RC time constant circuit conveys slowly the output voltage variation of loop filter and its output looks like constant voltage. The output signal of the comparator controls the sub charge pump and reduces the input voltage variation of voltage-controlled oscillator (VCO). Therefore, the proposed PLL generates a phase noise reduced signal. It has been designed with a 1.8V supply voltage, 0.18um multi - metal and multi - poly layer CMOS process and proved by Hspice simulation.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.245-250
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• 2019

Prussian blue (PB) is well known for its excellent $Cs^+$ ions adsorption capacity. Due to the high dispersibility of PB in aqueous phase, composite materials imbedding PB in supporting materials have been introduced as a solution. However, building PB particles inside porous supporting materials is still difficult, as PB particles are not fully formed and elute out to water. In this study, we suggest layer-by-layer (LBL) assembly to provide better immobilization of PB on supporting materials of poly vinyl alcohol sponge (PVA) and cellulose filter (CF). Three different PB attachment methods, ex-situ/in-situ/LBL assembly, were evaluated using PB leaching test as well as $Cs^+$ adsorption test. Changes of surface functionality and morphology during PB composite preparation protocols were monitored through Fourier transform infrared spectroscopy and scanning electron microscopy. The results indicate that LBL assembly led to better PB attachment on supporting materials, bringing less eluting PB particles in aqueous phase compared to other synthesis methodologies, such as ex-situ and in-situ synthesis. By enhancing the stability of the adsorbent, adsorption capacity of PVA-PB with LBL improved nine times and that of CF-PB improved over 20 times. Therefore, the results suggest that LBL assembly offers a better orientation for growing PB particles on porous supporting materials.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.5
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• pp.734-739
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• 2018

Fingerprint recognition and iris recognition, which are one of the biometric methods, are easily influenced by external factors such as sunlight. Recently, finger vein recognition is used as a method utilizing internal features. However, for accurate finger vein recognition, it is important to clearly separate vein and background regions. However, it is difficult to separate the vein region and background region due to the abnormalized illumination, and a method of separating the vein region and the background region after normalized the illumination of the input image has been proposed. In this paper, we proposed a method to enhance the quality improvement and improve the processing time compared to the existing finger vein recognition system binarization and labeling method of the image including the image stretching process based on the existing illumination normalization method.

• The Journal of the Acoustical Society of Korea
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• v.17 no.5
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• pp.57-62
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• 1998

본 논문에서는 입력신호의 시변특성에 따라 분석 필터의 대역을 가변 시키는 필터 뱅크의 구조를 제안한다. 제안된 필터뱅크는 일반적으로 32개의 균일한 대역으로 나누어 임 계대역의 표현을 적절히 표현하지 못하는 Polyphase 필터의 단점을 극복하면서 시스템 설 계에 높은 계산량을 요구하는 QMF-tree 필터의 단점을 보완한다. 본 연구에서는 분할 대역 은 4개에서 26개의 대역으로 가변하고, 웨이블릿 필터중 Daubechies필터를 사용하였다. 제 안된 구조의 부호화기는 128kbps에서 MPEG-a오디오와 비슷한 수준의 CD 음질을 유지하 며, 연산량 비교결과는 PolyPhase filter를 이용한 MPEG보다 부호화, 복호화 과정을 합쳐 다양한 전송률과 음원에서 평균 19%의 감소를 얻었다.