• 한국정보전자통신기술학회논문지
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• 제8권2호
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• pp.128-132
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• 2015

논문은 이중 급전을 갖는 마이크로스트립 이중 모드 대역 통과 필터를 제안한다. 제안된 필터는 이중 모드 구현을 위해 모서리 부분을 제거되고, 직교 슬롯을 포함하는 정사각형 패치와 이중 급전 구조로 구성된다. 직교 슬롯은 공진기의 소형화 및 불요신호를 억압하기 위해 사용되고, 상측 차단 대역에서의 차단 특성을 개선하기 위해 이중 급전 구조를 사용하였다. 보다 자세한 필터 설계 방법 및 특성 결과를 본문에 기술하였다.

• 전기학회논문지P
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• 제66권4호
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• pp.200-205
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• 2017

In this paper, we propose a technique to determine the normal and arc of an alternating current using a mixed filter composed of an average filter and a band-pass filter and a frequency analysis. The proposed method uses the moving average filter of the FIR filter structure for noise removal and the band-pass filter of the IIR filter structure for detecting only specific frequency components after normalizing the measured current signal based on the maximum value. After performing Fast Fourier Transform (FFT) using the band-pass filtered signal, the total energy is calculated using the magnitude component of the frequency, and the arc is detected using the magnitude of the calculated energy. In order to show the validity of the proposed method, we experimented with various data and found that arc and steady state can be easily discriminated by calculating spectral energy. Therefore, it is considered that the proposed method can be applied to arc diagnosis of low voltage electric wire.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제2권2호
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• pp.115-121
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• 2002

This paper presents an evolutionary design of digital IIR filters using the genetic algorithm (GA) with modified genetic operators and real-valued encoding. Conventional digital IIR filter design methods involve algebraic transformations of the transfer function of an analog low-pass filter (LPF) that satisfies prescribed filter specifications. Other types of frequency-selective digital fillers as high-pass (HPF), band-pass (BPF), and band-stop (BSF) filters are obtained by appropriate transformations of a prototype low-pass filter. In the GA-based digital IIR filter design scheme, filter coefficients are represented as a set of real-valued genes in a chromosome. Each chromosome represents the structure and weights of an individual filter. GA directly finds the coefficients of the desired filter transfer function through genetic search fur given filter specifications of minimum filter order. Crossover and mutation operators are selected to ensure the stability of resulting IIR filters. Other types of filters can be found independently from the filter specifications, not from algebraic transformations.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권10호
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• pp.630-638
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• 2005

In FIR (Finite Impulse Response) filter applications, Nth-band F]U digital filters are known to be important due to their reduced computational requirements. The conventional methods for designing F]U filters use iterative approaches such as the well-known Parks-Mcclellan algorithm. The Parks-Mcclellan algorithm is also used to design Nth-band FIR digital filters. But a disadvantage of the Parks-Mcclellan algorithm is that it needs a good amount of design time. This paper describes a direct design method for Nth-band FIR Filters using Chebyshev polynomials, which provides a reduced design time over indirect methods such as the Parks-Mcclellan algorithm. The response of the resulting filter is equiripple in passband. Our proposed method produces a passband response that is equripple to within a minuscule error, comparable to that of the Parks-Mcclellan algorithm.

• ETRI Journal
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• 제28권3호
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• pp.393-396
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• 2006

This letter proposes a new impedance matching scheme of a traveling wave electro-absorption modulator (TWEAM) module for a 60 GHz band radio-over-fiber (ROF) link. A microstrip band pass filter (BPF) was used to achieve impedance matching at the 60 GHz band, and termination resistance was carefully designed to obtain an input impedance close to $50\;{\Omega}$. Also, a bias circuit for the device was designed in the module. The measured return loss and frequency response show that the modulator module observes the characteristics of a filter without the need of a further tuning process.

• 한국조명전기설비학회지:조명전기설비
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• 제10권3호
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• pp.47-54
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• 1996

본 논문에서는 정보설비용 개인 휴대 통신 장치 대역 통과 필터를 설계 제작하였다. 대역 통과 필터를 설계 제작하기 위하여 유전체 공진기 구조에 따른 특성을 분석하였다. J-인버터 이론을 이용한 대역 통과 필터의 설계 이론과 시뮬레이션 결과를 알아보았다. 설계 이론으로부터 구한 파라미터를 이용하여 실제 제작한 결과 미세 조정 후 특정한 결과와 시뮬레이션 결과와 일치함을 볼 수 있다.

• 대한전자공학회논문지TC
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• 제41권1호
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• pp.69-72
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• 2004

접지면에 PBG와 Aperture를 설치함으로써 고성능 대역통과 여파기를 설계하였다. 대역통과 여파기의 하모닉 특성은 PBG 구조에 의하여 개선되었고 대역폭은 Aperture에 의하여 확대되었다. 세가지 크기를 갖는 PBG 구조가 결합되어 새로운 PBG 구조가 도출되었다. 설계 중심 주파수는 2.2 GHz이었고 대역폭은 Aperture에 의하여 $40\%$ 확대되었다.

• ETRI Journal
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• 제29권4호
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• pp.533-535
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• 2007

For the purpose of decreasing intermodulation distortion, a new multi-harmonic suppression band-pass filter based on a microstrip radial stub is studied. Compared with traditional resonator filters, the new filter can suppress the second, third, and even fourth harmonics directly. The dimension of the filter is about $0.3\;{\lambda}_{g^0}{\times}0.13\;{\lambda}_{g^0}$ (${\lambda}_{g^0}$ is the guiding wavelength at the resonant frequency). Only one gap was introduced, so lower insertion loss can be obtained. Basic agreement between the measured and simulated results has been achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.653-655
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• 1997

In this paper, a monoblock dielectric filter for 900MHz band CT-1 is designed by using CAD(Computer Aided Design). Equivalent circuit for monoblock dielectric filter represented by parallel coupled stripline is simulated by using SuperCompact software tool. A Designed filter structure is simulated by using HFSS to optimize result.

• 한국전자파학회논문지
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• 제21권12호
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• pp.1423-1431
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• 2010

본 논문은 평행 결합 선로를 이용한 이중 대역 소형 광대역 대역 통과 필터에 대하여 제안한다. 제안한 필터는 크기가 작고 대역폭의 조절과 이중 대역 운용이 가능하다. 뿐만 아니라 T-형태의 대역 저지 필터를 삽입하여 이중 대역의 지원이 가능하도록 하였다. 이중 대역의 대역 통과 필터는 첫 번째 운용 중심 주파수와 대역폭이 각각 5.8 GHz 및 60 %, 그리고 두 번째 운용 주파수 중심 주파수와 대역폭은 각각 16.2 GHz 및 60 %이다. 첫번째 주파수의 삽입 및 반사 손실은 각각 0.4 dB 및 17.4 dB를 갖고 있고, 두 번째 주파수의 삽입 및 반사 손실은 각각 0.62 dB 및 19.8 dB를 갖는다.