• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1998년도 하계학술대회 논문집 G
• /
• pp.2464-2466
• /
• 1998

A switch is a component with two or more ports that selectively transmits, redirects, or blocks optical power in a fiber transmission line. Our switch uses rotation mechanism using stepping motor, hence the common optical fiber can scan and allign to one of the arrayed N optical fibers to provide optical path by electronic precise control. The developed switch is consisted of switching module and its control module. The performance parameters of a switching loss and a repeatability are considered very important. We performed the study to reduce the switching loss and improve the repeatability of switch. The switch can be widely used as a test instrument of optical device and of optical cable in factory, also of optical cable monitoring systems.

• Journal of electromagnetic engineering and science
• /
• 제14권4호
• /
• pp.411-414
• /
• 2014

A switch is one of the most useful circuits for controlling the path of signal transmission. It can be added to digital circuits to create a kind of gate-level device and it can also save information into memory. In RF subsystems, a switch is used in a different way than its general role in digital circuits. The most important characteristic to consider when designing an RF switch is keeping the isolation as high as possible while also keeping insertion loss as low as possible. For high isolation, we propose leakage signal cancellation and inductive switching for designing a singlepole double-throw (SPDT) RF switch. By using the proposed method, an isolation level of more than 23 dB can be achieved. Furthermore, the heterojunction bipolar transistor (HBT) process is used in the RF switch design to keep the insertion loss low. It is demonstrated that the proposed RF switch has an insertion loss of less than 2 dB. The RF switch operates from 1 to 8 GHz based on the $0.18-{\mu}m$ SiGe HBT process, taking up an area of $0.3mm^2$.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 1998년도 추계종합학술대회 논문집
• /
• pp.289-440
• /
• 1998

This paper describes an interconnection network structure which transports information among processors through a high speed ATM switch. To efficiently use the high speed ATM switch for the message-based multiprocessor, we implemented the cell router that performs multiplexing and demultiplexing of cells from/to processors. In this system, we use the expanded internal cell format including 3bytes for switch routing information. This interconnection network has 3 stage routing strategies: ATM switch routing using switch routing information, cell router routing using a virtual path identifier (VPI) and cell reassembly routing using a virtual channel indentifier (VCI). The interconnection network consists of the NxN folded switch and N cell routers with the M processor interface. Therefore, the maximum number of NxM processors can be interconnected for message communication. This interconnection network using the ATM switch makes a significant improvement in terms of message passing latency and scalability. Additionally, we evaluated the transmission overhead in this interconnection network using ATM switch.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제51권12호
• /
• pp.584-590
• /
• 2002

Crowbar system is usually applied to a pulsed power system in which a capacitor bank is discharged into a load. This provides a free wheeling path for the load current and prevents the capacitor from recharging due to a reverse voltage. Usually diodes have been used as a crowbar switch, but it is not a practical system because the cost of the diodes goes up enormously with increasing the system voltage and current. This paper presents a novel protection scheme of a charging and discharging system of a 300 kJ capacitor bank using a low-cost crowbar system which consists of a crowbar switch and resistors. Triggered vacuum switch(TVS) was used for a crowbar switch, and Rogowski coil was used to determine a trigger time of TVS. When this crowbar system is applied to our pulsed power system which consists of capacitor bank($123muF$), inductor() for forming a pulse, load resistor$(100 m\Omega)$, and a closing switch, instantaneous reversal voltage of capacitor bank could be limited less than 1.8 ㎸ until capacitor bank was charred to 17 ㎸.

• 정보처리학회논문지A
• /
• 제9A권4호
• /
• pp.547-554
• /
• 2002

본 논문은 분산 공유메모리 환경의 다단계 버스망을 위한 동적 라우팅 방범을 제안한다. 제안된 라우팅 방법의 특징은 다단계 버스망이 제공하는 잉여경로를 활용하고 스위치 트래픽에 따라 적응적으로 경로를 결정하여 스위치의 트래픽을 분산시키는 것이다. 구체적으로는 잉여경로 상의 다음 단계 스위치의 트래픽 정도가 높고 낮음을 판단하여 트래픽 정도가 낮은 스위치로 패킷을 전달한다. 그 결과 평균 응답시간과 스위치상의 평균 대기패킷수를 줄이는 효과를 얻는다. 프로세서수와 스위치 크기를 변화시키면서 시뮬레이션을 하여 제안된 알고리즘이 잉여경로를 고려하지 않는 기존의 알고리즘에 비하여 평균 응답시간은 약 9%, 스위치 상의 평균 대기패킷수는 21.6% 정토 향상시킨다는 것을 보여준다

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 연구회 합동 학술발표회 논문집
• /
• pp.28-32
• /
• 1998

This paper presents novel ZVZCS PWM DC-DC converters. The proposed soft-switching technique achieves ZVS and ZCS simultaneously at both turn-on and turn-off of the main switch and diode by using only one auxiliary switch. Also, the proposed soft-switching technique is suitable for not only minority but also majority carrier semiconductor devices. The auxiliary circuit of the proposed topology is placed out the main power path and therefore, there are no voltage/current stresses on the main switch and diode. The operating principle of the proposed circuit is illustrated by a detailed study with the boost converter as an example. The validity of the proposed converter is verified by theoretical analysis, simulation and experiment results.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(2)
• /
• pp.205-208
• /
• 2002

An existing ATM switch fabric uses VPI(Virtual Path Identifier) and VCI(Virtual Channel Identifier) information to route ATM cell. But AAL type 2 switch which efficiently processes delay-sensitive, low bit-rate data such as a voice routes the ATM cell by using CID(Channel Identification) field in addition to VPI and VCI. In this paper, we research the AAL type 2 switch that performs the process of CPS packet. The Receive unit extracts the CPS packet from the inputted ATM cell. The designed receive unit consists of input FIFO, r)( status table, CAM(Content Addressable Memory), new CID table and partial packet memory. Also the designed receive unit supports the PCI interface with host processor. The receive unit is implemented in Xilinx FPGA and operates at 72MHz.

• 컴퓨터교육학회논문지
• /
• 제14권6호
• /
• pp.83-89
• /
• 2011

이 연구에서는 스마트 HDMI 스위치를 제안하는데, HDMI 플러그를 물리적으로 빼고 다시 껴는 일이 없는 상태에서 새로이 형성되는 비디오 스트림을 감지해서 자동적으로 전송 경로를 해당 포트로 전환해 주는 것이 주된 내용이다. 더 나아가 제안하는 시스템은 밀리미터 밴드 기술을 기반으로 진보된 무선 비디오 전송 구조 안에서 설계되었다. 하드웨어 실험을 통해서 제안된 시스템이 스마트 포트 전환 기능을 포함하는 가운데 풀 HD 비디오 전송 성능을 갖는 것을 보임으로써 그 유용성을 확인하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.111-114
• /
• 2002

We propose and fabricate a vertically integrated waveguide thermo-optic switch. It controls the optical path between two vertically stacked waveguide. As a first step, we fabricate polymeric waveguides. The measured propagation loss is ranged from 0.3 db/cm to 0.4 dB/cm at the wavelength of 1.55 $\mu\textrm{m}$. We fabricate the proposed vertically integrated waveguide thermo-optic switch to demonstrate its preliminary feasibility. The measured crosstalk is better than -10 db. The power consumption is about 500 mW. Further effort is necessary to improve its performance.

• Journal of electromagnetic engineering and science
• /
• 제16권1호
• /
• pp.29-34
• /
• 2016

This paper proposes a reconfigurable microstrip diplexer, also known as a switchplexer, for use with single-switch operation of frequency band and output path. The proposed switchplexer is composed of a rectangular ring resonator and a switch on a shorting pin, which is inserted between the ring resonator and the ground plane. The rotated main current distributions occurring at different switch statuses provide the diplexer's different operating bands and different output ports. The performance of the simply designed switchplexer is successfully demonstrated via simulation and measurement.