• 전자공학회논문지T
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• 제35T권3호
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• pp.31-36
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• 1998

본 논문은 5.8㎓ 무선 LAN용 영상 제거 인터디지털 필터를 설계하고 실험하였다. 4∼8㎓ 주파수 대역에서 -30dBm의 입력 신호를 인가하여 중심주파수 5.775㎓ 근처에서 6.475㎓ 삽입손실이 발생하는데, 이때 RF 케이블 손실, 복사 손실, 각종 기생성분에 의한 손실 등을 제외하고 약 -3.3㏈정도의 삽입손실이 나타남을 알 수 있다. 특히, 영상주파수 6.475㎓에서 영상 신호 제거는 -l7㏈정도이고, 고주파 대역의 스컷 특성이 우수하므로, RF 영상신호 제거에 적합한 필터의 특성이 나타남을 확인하였다.

• 전자공학회논문지
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• 제54권6호
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• pp.25-29
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• 2017

본 논문에서는 듀로이드와 FR4를 기판으로 하는 재배선층 위에 정전 구동 방식의 RF MEMS 스위치와 승압 DC-DC 컨버터를 결합하는 연구를 진행하였다. 상용 PCB(Printed Circuit Board) 공정으로 듀로이드와 GCPW 전송 선로 조합의 재배선층과 FR4와 CPW 전송 선로 조합의 재배선층을 제작하였다. 상용 PCB 공정 특성에 의하여 전송 선로의 특성 임피던스는 56옴, 59옴 이었으며 이에 대하여 비교 분석하였다. 듀로이드 기판은 유전상수가 작고 두께가 얇으며 GCPW를 적용하였기 때문에 상대적으로 유전상수가 크고 두께가 두꺼우며 CPW 전송 선로를 적용한 FR4 기판보다 6GHz 대역에서 삽입 손실은 약 2.08dB, 반사 손실은 약 3.91dB, 신호 분리도는 약 3.33dB 우수한 것을 확인하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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• pp.222-226
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• 2001

In this paper, 2.4GHz RF Module using Even Harmonic Mixer(EHM) was designed and fabricated for Direct conversion(DC) system. By minimizing performance degradation of DC system with DC offset and LO radiation, the capability of minimization and one chip solution in wireless system was proposed. The designed EHM using anti-parallel diode pair represented 9dB conversion loss and about -60dBm 2LO leakage radiation in RF port, and output reflection and reverse transmission characteristic of low noise amplifier was improved. So superior DC offset suppression characteristic is expected. RF Module which consists of EHM, LNA, RF amplifier, Frequency synthesizer and Duplexer was designed and fabricated.

• JSTS:Journal of Semiconductor Technology and Science
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• 제7권3호
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• pp.177-182
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• 2007

This paper presents the see-saw type RF MEMS switch based on a single crystalline silicon structure with narrow gap vertical comb. Low actuation voltage and high isolation are key features to be solved in electrostatic RF MEMS switch design. Since these parameters in conventional parallel plate RF MEMS switch designs are in trade-off relationship, both requirements cannot be met simultaneously. In the vertical comb design, however, the actuation voltage is independent of the vertical separation distance between the contact electrodes. Therefore, the large separation gap between contact electrodes is implemented to achieve high isolation. We have designed and fabricated RF MEMS switch which has 46dB isolation at 5GHz, 0.9dB insertion loss at 5GHz and 40V actuation voltage.

• 한국세라믹학회지
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• 제41권3호
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• pp.197-201
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• 2004

플라즈마 화학기상증착(PECVD)법을 이용하여 Si(100) 웨이퍼에 silicon oxide(SiO$_2$)와 silicon oxynitride(SiON) 후막을 SiH$_4$, $N_2$O, $N_2$가스를 혼합하여 증착하였다. RF power와 rf bias power의 변화에 따른 SiO$_2$ 막과 SiON 막의 특성변화에 대하여 고찰하였다. RF power와 rf bias power가 증가함에 따라 굴절률은 감소하는 경향을 나타내었으며, 막의 굴절률은 1552 nm에서 1.4493-1.4952까지 변화하였다. 이와 같이 rf power가 증가함에 따라 굴절률이 감소하는 이유는 oxygen의 량이 증가하고 nitrogen의 량이 감소하여 즉, O/N 비가 증가하여 굴절률이 감소하는 경향을 나타내었다.

• ETRI Journal
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• 제32권2호
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• pp.195-203
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• 2010

A new vertical transition between a substrate integrated waveguide in a low-temperature co-fired ceramic substrate and an air-filled standard waveguide is proposed in this paper. A rectangular cavity resonator with closely spaced metallic vias is designed to connect the substrate integrated waveguide to the standard air-filled waveguide. Physical characteristics of an air-filled WR-22 to WR-22 transition are compared with those of the proposed transition. Simulation and experiment demonstrate that the proposed transition shows a -1.3 dB insertion loss and 6.2 GHz bandwidth with a 10 dB return loss for the back-to-back module. A 40 GHz low-temperature co-fired ceramic module with the proposed vertical transition is also implemented. The implemented module is very compact, measuring 57 mm ${\times}$ 28 mm ${\times}$ 3.3 mm.

• ETRI Journal
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• 제36권1호
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• pp.106-115
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• 2014

In this work, the coplanar waveguide is fabricated on a PES (poly[ether sulfone]) substrate for application to a flexible monolithic microwave integrated circuit, and its RF characteristics were thoroughly investigated. The quality factor of the coplanar waveguide on PES is 40.3 at a resonance frequency of 46.7 GHz. A fishbone-type transmission line (FTTL) structure is also fabricated on the PES substrate, and its RF characteristics are investigated. The wavelength of the FTTL on PES is 5.11 mm at 20 GHz, which is 55% of the conventional coplanar waveguide on PES. Using the FTTL, an impedance transformer is fabricated on PES. The size of the impedance transformer is $0.318mm{\times}0.318mm$, which is 69.2% of the size of the transformer fabricated by the conventional coplanar waveguide on PES. The impedance transformer showed return loss values better than -12.9 dB from 5 GHz to 50 GHz and an insertion loss better than -1.13 dB in the same frequency range.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1507_1508
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• 2009

This study proposes a composite right/left-handed transmission line (CRLH-TL) that permits switching between the right-handed (RH) and left-handed (LH) modes using single crystalline silicon (SCS) RF MEMS switches. It is possible to change modes from the RH to LH mode, or vice versa, by controlling the admittance of capacitors and the impedance of inductors using switch operations. The proposed switchable CRLH-TL consists of SCS RF MEMS switches, metal-insulator-metal (MIM) capacitors and shunt inductors. At 8 GHz, the fabricated device shows a phase response of $87^{\circ}$ with an insertion loss of 2.7 dB in the LH mode, and a phase response of $-77^{\circ}$ with an insertion loss of 0.56 dB in the RH mode.

• Journal of electromagnetic engineering and science
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• 제11권4호
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• pp.274-281
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• 2011

High-speed telecommunication systems are influenced by electromagnetic environments because they need a wide bandwidth to transmit signals. Immunity tests of telecommunication equipment are effective for improving its immunity to electromagnetic environments. However, immunity tests are expensive to carry out because there are several different tests. The correlation among the tests should therefore be examined in order to reduce the kinds of tests that are necessary. This paper investigates the correlation between the electrical fast transient/burst (EFTB) test and the radio frequency (RF) conductive immunity test. Imitation equipment was constructed with a balun, and a baseband signal was transmitted from the associated equipment to the imitation equipment. Then, disturbances were applied to the equipment, and the telecommunication quality was evaluated by using the bit error rate (BER). The results from the EFTB test indicated that the BER was less than $6{\times}10^{-5}$ and the value was independent of the peak value. The results from the RF conductive immunity test indicated that the BER was affected by the longitudinal conversion loss (LCL).

• 한국전자통신학회논문지
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• 제3권4호
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• pp.282-288
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• 2008

본 연구에서는 고출력 RF 필터의 도금상태에 따른 수동혼변조왜곡(PIMD)을 측정하였으며 RF-filter의 PIMD를 저감시키기 위한 방안을 제시하였다. PIMD의 표준측정방안에 따라 Wibro 중계기용 고출력 RF-필터의 PIMD 특성를 측정하였다. Wibro용 고 전력-RF 필터의 설계에서 통과대역의 에지(edge)에서 삽입손실 및 지연 특성의 평탄도가 저하될 경우, PIMD의 발생되므로 본 연구에서는 고 전력 필터의 PIM을 감소시키기 위하여 필터의 내부 도금 재료의 종류와 방안을 제시하였다.