• ETRI Journal
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• 제27권5호
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• pp.643-646
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• 2005

This letter proposes a band-pass filter (BPF) with two transmission zeros based on a combination of parallel coupling and end coupling of half-wave transmission lines. The fabricated BPF exhibited a narrow bandwidth and two transmission zeros near the pass-band due to the end-coupled and shielding waveguide. At the center operation frequency of 60 GHz, the 20 dB bandwidth of the BPF is 1.0 GHz, which is almost 2% of the center operation frequency, and the insertion loss is 3.12 dB. Two transmission zeros reach approximately 40 dB at 58.5 and 62.5 GHz. The simulation results almost agree with the measured results.

• Transactions on Electrical and Electronic Materials
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• 제18권2호
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• pp.62-65
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• 2017

In this paper, three DC Block designs are presented which efficiently meet the need of modern-day compactsize wireless communication systems. As one of the important parts of a complete system design, the proposed microstrip-based DC block with coupled transmission lines efficiently attenuates unwanted frequencies that cause damage to the system. The compact-sized DC block structures are created by incorporating an extended coupled-line section with a radial stub, an enveloped coupled-line section, and using alternate up-down meandering techniques. The structures are analyzed for the L-Band using a high-resistive silicon substrate. At a resonating frequency of 1.575 GHz, the designed DC Block structures have a return loss better than -10 dB, an insertion loss of around -1 dB, and also possess wide pass-band characteristics.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.183-185
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• 2010

A 2.4 GHz dual-polarized antenna for a Doppler radar is studied. The proposed dual-polarized antenna using a stacked annular ring patch with two co-centric gap-coupled feed lines and a $90^{\circ}$ hybrid exhibits fairly good performance of 22 dB isolation at a center frequency of 2.4 GHz. Using a $90^{\circ}$ hybrid, a right-handed circular polarization for the transmitter and a left-handed circular polarization for the receiver are implemented. The gain of the designed antenna is about 0 dBi over operating frequencies. The antenna size including a ground plane is only $40{\times}40\;mm^2$.

• 한국결정성장학회지
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• 제12권6호
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• pp.288-291
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• 2002

We developed a new RF indirect-heating LPE furnace. The thermal gradient of our newly developed furnace is less than that of direct heating, and is as gentle as that of the resistance-heating LPE furnace. With this new furnace, the heating and/or cooling is faster than that of the resistance-heating furnace. Impurity-doped YIG film was grown from a $PbO-B_{2}O_{3}$, based flux on a (111) GGG substrate. To study the effect of the impurities on the MSSW threshold power and the saturation response time, we used two microstrip lines to excite and propagate the MSSW at 1.9 GHz. The MSSW threshold power and saturation response time was found to be related to the $\Delta$H.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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• pp.323-325
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• 1997

Conventionally it is asummed that the microstrip line conductor has a rectangular cross-section. but the additive and substactive processes used to create conductors for PCBs produce a conductor of approximately Trapezoidal cross-section. For wide Strip line, the thickness and edge effect will be small since most of capacitance is parallel plate rather than fringing and we can ignore the cross-section. For narrow strip lines, the edge effect become immportant. So in this paper, we measure the chracteristic impedance of microstripline by Vector Analyzer and simulate the electromagnetic field of microstripline using finite element method with edge angle.

• ETRI Journal
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• 제27권2호
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• pp.166-171
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• 2005

In this paper, a synthesis technique for nonuniform filtering structures to be employed in active integrated antenna layouts is presented. The idea is to suppress the higher harmonic contribution due to the presence of nonlinear components through a nonuniform transmission line properly designed via Orlov's synthesis formula. The theory presented is applied here to synthesize an amplifier-based active antenna layout for wireless local area network (WLAN) purposes working at 2.4 GHz. The numerical results presented show the capabilities of the proposed approach.

• 전자공학회논문지
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• 제50권2호
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• pp.54-59
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• 2013

이중대역에서 동작하는 브랜치 라인 커플러를 나타낸다. 새로운 설계 구조에서는 단락 스터브가 병렬로 추가된 전송선로가 2개의 주파수에서 $90^{\circ}$의 위상 천이를 구현하기 위하여 사용된다. 제안하는 브랜치 라인의 특성 임피던스와 전기적 길이는 종래의 구조와 비교하여 조정된다. ABCD 행렬 파라미터를 이용하여 설계 방정식을 유도하였다. 설계 개념을 검증하기 위하여 0.8 GHz 및 1.85 GHz에서 동작하는 마이크로스트립 커플러를 제작하고 측정하였다.

• 한국통신학회논문지
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• 제21권5호
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• pp.1304-1316
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• 1996

In this paper, A VCO(Voltage Controlled Oscillator) in use of clock recovery/data regeneration circuit for 10 Gbps fiber optic receivers was developed. The improved hair-pin resonator with a parallel coupled lines, which has been applied to microstrip filters, was used as a resonance part. As a frequcncy tuning device by substituting 3-terminalMESFET vaaractor for varactor diode, an MMIC manufacturing process will be simplified. Since a hair-pin resonator is planar type compared to the dielectric resonator and has a relatively flat reactance verus frequency, it will be favorable to apply a hair-pin resonator to an MMIC, in addition wideband frequency tuning range is able to be obtained.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권2호
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• pp.81-85
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• 2005

This paper presents some interesting results regarding the harmonic performance on the photonic band-gap (PBG) structures formed by periodic conducting vias. Study on PBG structures has been one of the major topics in electromagnetics, microelectronics, and communications areas. In most of the studies, the band-gap filtering behavior was fulfilled by a periodic pattern of perforations on the ground planes of microstrip lines. Nevertheless, the PBG characteristics can also be realized using a periodic via-pattern along the transmission-line circuits. Hence, some of the via-typed PBG structures are studied and their frequency characteristics in terms of the scattering parameters are presented. It is found that by varying the length of vias with respect to the period pattern, different harmonic performances are observed.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.328-332
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• 2000

본 논문에서는 기생 패치 구조와 적층 구조의 광대역 마이크로스트립 안테나에 평행 결합 선로 형태의 광대역 임피던스 정합 회로를 결합하여 쉽게 추가적인 임피던스 대역폭 개선을 얻을 수 있음을 제안하였다. 평행 결합 선로 형태의 광대역 임피던스 정합 회로 설계를 위하여 분포 회로 방식의 반복적인 방법을 제시하였고. 설계\ulcorner제작 결과 기생 패치 구조와 적층 구조에서 각각 56.23%와 16.45%의 추가적인 임피던스 대역폭 개선을 이룰 수 있었다. 그리고 방사 패턴과 측정된 이득을 보면 평행 결합 선로의 결합으로 인한 방사 패턴에서의 큰 변화는 보이지 않았고, 이득에서는 평행 결합 선로 부분의 커플링 손실로 인해 최대 이득이 약 1 dB 정도 감소하는 것을 확인할 수 있었다.