• 대한전자공학회논문지SD
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• 제45권4호
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• pp.86-93
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• 2008

2.4 GHz 대역 완전차동 직접변환 수신기를 위한 저전력, 저잡음, 고선형성을 가지는 새로운 구조의 하이브리드 발룬(Hybrid Balun) 회로를 제안한다. 제안된 하이브리드 발룬은 수동형 트랜스포머(Passive Transformer)와 손실 보상용 보조 증폭기(Loss-compensating Auxiliary Amplifiers)로 구성된다. 트랜스포머와 보상용 증폭기 사이의 신호의 분리와 결합에 대한 설계 이슈들을 제시하였다. $0.18{\mu}m$ 공정으로 제작된 하이브리드 발룬은 수동형 발룬에 비해 2.4 GHz 대역에서 이득은 2.8 dB 높고 잡음지수는 1.9 dB 낮으며, 측정된 IIP3는 +23 dBm 이다. 전체 전력소모는 1.2 V 전원 전압에서 0.67 mA로서 저전력으로 구현되었다. 하이브리드 발룬 기술을 적용하여 설계된 무선센서노드용 CMOS 직접변환 수신기는 수동형 발룬을 사용했을 때 비해 0.82 mW의 추가 전력소모만으로 전체 잡음 지수를 현저히 낮출 수 있음을 확인하였다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.15-20
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• 2000

We demonstrated a single balanced mixer of the combination of high-T. superconductor (HTS) and III-V GaAs beam lead Schottky diodes operating in the mini-cryogenic chamber. The HTS hybrid mixer was designed with a center frequency of 27.5 GHz and a bandwidth of 1 GHz, and consisted of a rat-race coupler circuit with beam-lead diodes attached to its balanced ports. The HTS hybrid mixer with 1 GHz RF bandwidths exhibits a conversion loss of 6 dB. A LO-to-RF isolation was greater than 40 dB in the range of operating frequencies. Since the HTS/III-V hybrid mixer devices have lower noise and conversion loss, this technique provide us with new capabilities that can be effectively utilized in the field of local-point distribution service (LMDS) systems.

• Transactions on Electrical and Electronic Materials
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• 제8권5호
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• pp.222-225
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• 2007

In this paper, we compared the current limiting characteristics of both the hybrid type and the flux-lock type superconducting fault current limiters(SFCLs), which have a magnetic coupling structure between a primary winding and several secondary windings. The limiting impedances of two SFCLs were derived from each equivalent circuit considering the design parameters of SFCL such as the self-inductance of secondary winding and the resistance of $high-T_C$ superconducting(HTSC) element. Through the comparison for the limiting impedances of two SFCLs considering the dependence of the HTSC element's resistance on the applying voltage into the SFCL, the hybrid type SFCL was confirmed to have larger limiting impedance with smaller resistance of HTSC element than the flux-lock type SFCL. It was expected from the analysis that the hybrid type SFCL was more advantageous than the flux-lock type SFCL from the viewpoint of the fault current limiting level.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2003년도 국제표면실장 및 인쇄회로기판 생산기자재전:전자패키지기술세미나
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• pp.1-19
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• 2003

The electronic market thrust for many hybrid circuit manufacturers is changing because commercial market segments such as telecommunications, automotive and consumer electronics have increased the demand world wide for environmentally friendly thick film products. This, in turn, places a stronger emphasis on the material suppliers within the circuit fabrication industry to provide toxin free products with equal or higher performance than traditional technology. A new group of silver based thick film conductors, which are totally free of such toxins as cadmium, nickel and Bead have been developed to meet new environmental requirements. Traditional thick film products and newly developed toxin free compositions will be compared and data will be presented. To evaluate their performance, both groups of conductors were tested for solder acceptance, leach resistance and aged adhesion with standard lead-containing solder and higher temperature lead-free solder.

• 한국전자파학회논문지
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• 제19권8호
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• pp.862-877
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• 2008

두 종류의 넓은 대역폭을 갖는 ring hybrids(하나는 coupled line이 포함되어 있고, 다른 하나는 left-handed transmission line을 포함한 ring hybrids)가 비교되었으며, 비교 결과로부터 coupled line을 포함한 ring hybrid가 모든 면에서 우수한 특성을 가짐을 보여줬다. 그러나, coupled line을 포함한 ring hybrid는 -3 dB coupling power를 가질 경우에 한해서만이 perfect matching이 이루어지기 때문에, perfect matching을 갖는 coupled line ring hybrid는 2차원으로 구현하기는 거의 불가능하다. 이 문제를 해결하기 위해서 coupled line을 해석했고, 그 해석 결과로부터 coupling coefficient에 관계없이 어느 경우에도 perfect matching을 이룰 수 있는 설계 식을 유도했다. 이 설계식을 이용하여, transmission line의 길이가 ${\pi}$보다 큰 경우에도 적용될 수 있는 크기를 줄이기 위한 새로운 형태의 transmission line 등가회로를 제시했다. 이 새로운 형태의 transmission line의 등가회로를 이용하면 기존의 ring hybrid의 $3\;{\lambda}/4$의 transmission line을 줄이는 데 사용할 수 있기 때문에 ring hybrid의 크기를 더욱 줄이는데 장점이 될 수 있다. 이 등가회로를 증명하기 위해서, coupling power를 고정하고 또는 transmission line의 길이를 고정하는 2가지 형태의 simulation을 하였으며, 대역폭은 coupled line의 coupling power에 직접적인 상관 관계가 있음을 보였다. 기존의 등가회로와 새로운 형태의 등가회로를 이용하여, 작고 넓은 대역폭을 가지는 ring hybrid를 제시하였다. 새로 제시된 ring hybrid를 이용하여, 기존의 ring hybrid와 비교하였다. 비교 결과로부터, 본 논문에서 제시한 ring hybrid의 전체 ring 둘레가 1/3보다 더 작음에도 불구하고, 대역폭이 훨씬 넓음을 보여줬다. 작고 넓은 대역폭을 가지는 ring hybrid를 측정했으며, 측정 결과는 -2.78 dB, -3.34 dB, -2.8 dB, -3.2 dB의 power division 특성을 보여줬으며, matching과 isolation은 20 % 이상의 대역폭에서 -20 dB보다 좋은 특성을 보여줬다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.592-594
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• 2002

Hybrid stepping motor(HSM) has very small airgap and teeth. These bring out the saturation in the teeth easily. In this paper. the 3 dimension equivalent magnetic circuit network method (EMCNM) based on the trapezoidal element is used for the accurate and efficient nonlinear analysis of HSM. and the validity of the analysis results by the proposed method is verified by comparison with the experimental results.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.484-485
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• 2003

We report on the optimization of the fabrication process of hybrid sol-gel thin film deposition to produce low cost $1 {\times} 16$ splitters for optical communications. We learn that sol-gel film thickness is dependent upon the spinning speeds and viscosity of the sol-gel solutions and refractive index upon the dopant concentrations of Al and Zr in the sol solutions. We could find the optimized physical conditions to achieve the desired thickness of core and cladding layers. We will further carry out the fabrication and measurements of insertion loss, polarization dependent loss (PDL), etc. for the performance of fabricated splitter devices.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.85.1-85
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• 2001

A phase lock loop (PLL) circuit is a wellknown electronic circuit in communication engineering and other areas. In this paper, we present application of the PLL and fuzzy logic for DC motor control which are mixed well to be more effective for motor control. With this scheme, the control system can reach the set point rapidly, especially, it can eliminate noises. In addition, the PLL makes the system to have more stability; whereas, fuzzy logic controls helping PLL to be able to lock rapidly for a good response. The experiment result shows that the proposed control system works more efficacious. By performance comparison between the pure PLL control and the hybrid architecture of PLL with the fuzzy control, the result reveals the hybrid control ...

• ETRI Journal
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• 제29권4호
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• pp.452-456
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• 2007

Very compact 4-channel 200-GHz-spacing external cavity lasers (ECLs) were fabricated by hybrid integration of reflection gratings and superluminescent laser diodes on a planar lightwave circuit chip. The fifth-order gratings as reflection gratings were formed using a conventional contact-mask photo-lithography process to achieve low-cost fabrication. The lasing wavelength of the fabricated ECLs matched the ITU grid with an accuracy of ${\pm}0.1$ nm, and optical powers were more than 0.4 mW at the injection current of 80 mA for all channels. The ECLs showed single mode operations with more than 30 dB side lobe suppression.

• 전기학회논문지P
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• 제57권3호
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• pp.231-235
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• 2008

Thyristor rectifiers are still the preferred choice for large magnet power supplies. However, large harmonic voltages, resulting in large current ripple, and slow dynamic response are major drawbacks of these converters. Joos presented a topology and a control technique for a hybrid large-power high-precision magnet power supply in 1996. The system consists of a phase controlled rectifier (PCR) connected in series with a high-frequency PWM converter. This paper improves the power circuit of the PWM converter using interphase transformer. Simulation result proves effect of the proposed system.