• Journal of electromagnetic engineering and science
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• 제11권2호
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• pp.83-90
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• 2011

In this paper, we present the design method for a low-pass type inverter, which can effectively suppress the spurious response associated with band-pass filters. The inverter has a length of ${\lambda}/4$ and employs not only a stepped-impedance configuration but also asymmetrical and bending structures in order to improve frequency selectivity and compactness. The inverter is applied as an impedance/admittance inverter to the ultra-wideband (UWB) band-pass filter. The UWB band-pass filter configuration is based on a stub band-pass filter consisting of quarter-wavelength impedance inverters and shunt short-circuited stubs ${\lambda}/4$ in length. The asymmetrical stepped-impedance low-pass type inverter improves not only the spurious responses, but also the return loss characteristics associated with a UWB band-pass filter, while a compact size is maintained. The UWB band-pass filter using the proposed inverters is fabricated and tested. The measured results show excellent attenuation characteristics at out-band frequencies, which exceed 18 dB up to 39 GHz. The insertion loss within the pass-band (from 3.1 to 10.6 GHz) is below 1.7 dB, the return loss is below 10 dB, and the group delay is below 1 ns.

• Journal of electromagnetic engineering and science
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• 제16권2호
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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.

• Journal of information and communication convergence engineering
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• 제22권3호
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• pp.173-180
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• 2024

This study proposed an interdigital band-pass filter based on the microstrip transmission line. When designing a conventional structure for an interdigital filter based on the characteristics of the 5th order transmission line, seven resonators are required. By changing the impedance of the resonator adjacent to the feed line, the proposed interdigital band-pass filter was designed to reduce the number of resonators compared to conventional interdigital band-pass filters. Consequently, the resonator order decreased, and return and insertion losses become comparable to that in case of a conventional interdigital filter design. The proposed band-pass filter was designed with a center frequency of 2.75 GHz and a bandwidth of 1.5 GHz. Furthermore, based on various transmission characteristics such as group delay and coupling coefficient, two band-pass filters were designed, compared, and analyzed.

• 대한전자공학회논문지TC
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• 제46권9호
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• pp.60-65
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• 2009

본 논문에서는 대역통과 여파기와 대역저지 여파기를 하나의 구조로 합성하여 크기 증가 없이 초광대역 특성을 가지면서 Wireless-LAN 대역을 저지하는 대역통과 여파기를 설계, 구현하였다. 대역저지 특성을 얻으면서도 여파기의 크기증가가 없어야 하기 때문에 전송선에 내장된 형태의 오픈 스터브를 사용하였다. 그리고 저역 통과 특성을 얻기 위하여 접지 면에 식각할 수 있는 DGS(Defected Ground Structure) 구조를 이용하였다. 기존의 대역통과 여파기와 저역통과 여파기를 직접 연결하였을 때 보다 크기를 줄일 수 있었다. 측정결과 통과대역은 $2.21GHz{\sim}10.92GHz$ 이고 삽입손실은 최대 0.7dB, 반사손실은 최소 17dB, 군 지연 변화폭은 0.22ns였으며 $5.3GHz{\sim}5.7GHz$의 저지대역을 형성하였다.

• Journal of the Optical Society of Korea
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• 제16권3호
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• pp.288-291
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• 2012

We designed an ultra-wide band-pass filter applicable to microwave reflectometry for KSTAR (Korea Superconducting Tokamak Advanced Research) and to microwave photonics. The proposed ultra-wide band-pass filter exhibits a metamaterial structure characterized by a wide band, low insertion loss, and high skirt selectivity. The proposed filter is applied to enhance the linearity of reflectometry at the output of a VCO (voltage controlled oscillator). The pass-band of the proposed filter is observed at 18~28 GHz, and the out-of-band rejection is below 20 dB. Further, we constructed an unwrapped negative phase of S(2, 1) to verify the characteristics of the metamaterial. The under- and upper-band at lower limits of the pass-band are left- and right-handed, respectively. The group delay of the filter is less than 0.5 ns.

• 대한전자공학회논문지TC
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• 제46권5호
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• pp.162-167
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• 2009

본 논문에서는 대역통과 여파기와 저역통과 여파기를 하나의 구조로 합성하여 크기 증가 없이 초광대역 특성을 가지는 여파기를 설계 및 구현하였다. 제안한 구조는 그 구조가 간단하다. 그리고 저역 통과 특성을 얻기 위하여 이미 잘 알려진 DGS(Defected Ground Structure) 구조를 이용하였다. 기존의 대역통과 여파기와 저역통과 여파기를 직접 연결하였을 때 보다 크기를 줄일 수 있었다. 측정결과 통과대역은 $2.1GHz{\sim}10.56GHz$이고 삽입손실은 최대 0.5dB, 반사손실은 최소 20dB, 군 지연은 $0.13ns{\sim}0.35ns$ 까지 최대 변화폭 0.23ns의 변화를 보인다.

• E2M - 전기 전자와 첨단 소재
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• 제9권9호
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• pp.933-941
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• 1996

In this study, the Tx(Transmitting) and Rx(Receiving) band pass filter for personal communication services was constructed and designed using .lambda./4 TEM mode dielectric resonators. Band pass filter was composed of ceramics resonators which has been developed using ($Zr_{0.65}$,$Sn_{0.35}$) $Ti_{1.04}$ $O_{4.04}$ ceramic and Unloaded-Q ( $Q_{o}$) of .lambda./4 TEM mode dielectric resonator with inner hole size 0.9mm and external size 3mm using silver electrode is 354.5 at 1.95GHz. For the band pass filter design and construction, the design theory and simulation results of band pass filter using J-inverter theory have been studied. The parameters which are evaluated by design theory are practically applied to the filter construction and the simulation results are in agreement with the measured results after fine tunnings.s.s.s.s.s.

• 한국통신학회논문지
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• 제10권5호
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• pp.250-257
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• 1985

고차 필터는 각 2차 함수를 종속연결함으로써 실현화한다. 본 논문에서는 다원함수의 고차 대여통과와 대역서지 필터 실현화에 있어서 전 동적범위를 향상시키기 위한 방법을 제시하였으며 고역통과 놋치, 저역통과 놋치 그리고 대칭 놋치등 각 2차함수들의 최적배열을 다원함수의 대역통과와 대역저지 필터에 적용하였다.

• 한국통신학회:학술대회논문집
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• 한국통신학회 1984년도 춘계학술발표회논문집
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• pp.25-28
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• 1984

This paper describes the design of band-pass filter using the dielectric resonator and microstrip line depends mainly upon the magnetic field and is principal parameter as band-pass filter. Because dielectric resonator band~pass filter has a very high-Q, the bandwidth of this filter is very narrow. as a result of experiment, the dielectric resonator bandwidth of this filter is very narrow. As a result of experiment, the dielectric resonator band-pase filter has various modes central frequencies due to the mode change and good characteristric as a band-pass filter.

• 대한전자공학회논문지TC
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• 제49권7호
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• pp.65-70
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• 2012

본 논문은 CRLH와 DGS 구조를 합성하여 초광대역 대역 통과 특성이 있으면서 통과대역 내에 조정가능한 이중대역 저지 기능이 있는 필터를 제안한다. 초광대역 대역통과 여파기는 WLAN과의 전파간섭을 피하기 위해 2.4GHz와 5.8GHz를 저지하여야 한다. 이를 위해 본 논문에서는 CRLH구조를 이용하여 2중 저지 대역을 형성하였으며 통과 대역 이후 주파수에서 우수한 대역 저지 효과를 얻기 위해 DGS구조를 합성하였다. 실제 제작된 여파기 측정결과 2.4GHz와 5.8GHz에서 30dB 이상의 저지 특성을 확인하였다. 차단 주파수는 CRLH의 파라미터를 변경함으로써 매우 쉽게 이루어질 수 있다. 제작된 여파기는 0.4dB(Lower Pass-Band), 0.7dB(Upper Pass-Band)의 삽입손실과 0.6ns 이하의 작은 Group Delay를 확인하였다. 또한 크기가 17mm*17mm 로 매우 소형이다.