• Progress in Superconductivity
• /
• 제7권1호
• /
• pp.36-40
• /
• 2005

The problem of fluctuation-induced digital errors in a rapid single flux quantum (RSFQ) circuit has been a very important issue. In this work, we calculated the bit error rate of an RSFQ switch used in superconductive arithmetic logic unit (ALU). RSFQ switch should have a very low error rate in the optimal bias. Theoretical estimates of the RSFQ error rate are on the order of $10^{-50}$ per bit operation. In this experiment, we prepared two identical circuits placed in parallel. Each circuit was composed of 10 Josephson transmission lines (JTLs) connected in series with an RSFQ switch placed in the middle of the 10 JTLs. We used a splitter to feed the same input signal to both circuits. The outputs of the two circuits were compared with an RSFQ exclusive OR (XOR) to measure the bit error rate of the RSFQ switch. By using a computerized bit-error-rate test setup, we measured the bit error rate of $2.18{\times}10^{-12}$ when the bias to the RSFQ switch was 0.398 mA that was quite off from the optimum bias of 0.6 mA.

• 인터넷정보학회논문지
• /
• 제9권2호
• /
• pp.15-23
• /
• 2008

본 논문에서는 고효율을 유지하며 QoS를 보장하는 새로운 구조의 다중 입출력 버퍼링 방식의 스위치와 이 스위치에서 사용되는 새로운 중재 알고리즘인 Anti-Empty 알고리즘을 제안한다. 새로운 스위치 구조는 MIQ와 MOQ를 기본으로 하여 외부회선 속도와 동일한 속도를 가지는 버퍼를 사용하는 구조로 설계되었으며 기존 방식의 단점을 제거하고 QoS를 지원하기 위해 MOQ의 동작 방법에 새로운 방식을 도입하였다. 이로서 스위치 전체의 수율과 지연 등의 성능이 고 효율의 출력 버퍼형 스위치와 동일하면서 셀 손실이 없는 QoS를 지원하는 고속 스위칭을 보장한다.

• 한국통신학회논문지
• /
• 제31권2A호
• /
• pp.201-206
• /
• 2006

다중 빔 위성중계기 부품중의 하나인 MSM(Microwave Switch Matrix)에 필요한 SPST 스위치 MMIC를 설계 및 제작하였다. 설계된 스위치 MMIC는 3GHz 대역에서 동작하며, 새로운 구조를 채택하여 기존의 FET 스위치보다 전력 특성과 격리도를 개선하였으며, 스위치의 On/Off 상태에서의 입출력 반사손실 특성이 우수하다. MMIC는 0.15um GaAs pHEMT 공정으로 제작되었으며, 3$\∼$4GHz 대역에서 2.0dB 이하의 삽입손실과, 63dB 이상의 격리도 성능을 가지는 것으로 측정되었다. 또한 사용된 단위 pHEMT 소자가 0.2mm Gate Width 임에도 불구하고 320dBm 이상의 OIP3 특성을 가지고 있는 것으로 측정되었으며, 이 결과는 기존의 발표된 FET 스위치에 비해 높은 전력 특성이다.

• 한국초전도저온공학회:학술대회논문집
• /
• 한국초전도저온공학회 2002년도 학술대회 논문집
• /
• pp.207-210
• /
• 2002

We had designed thermally controlled superconducting switches using a general nonlinear optimized algorithm with constraints and tested its performance. Objective function was to minimize the total volume of the superconducting switch. And constraints were to have designed resistance in normal status and temperature. In order to compare performance of the optimized superconducting switch, we made another one which had geometrically different parameters but had same structure and resistance value when the superconductor part is normal status by heater. Objective function converged very rapidly. As result, volume of the adiabatic part and total volume of the switch were reduced to more than 70% and 30% respectively. Also, even if same heater power was supplied with NiCr wire heater, the optimized superconducting switch had very fast On-OFF switching performance comparing with unoptimized switch.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제52권6호
• /
• pp.365-371
• /
• 2003

Input queued switch is useful for high bandwidth switches and routers because of lower complexity and fewer circuits than output queued. The input queued switch, however, suffers the HOL-Blocking, which limits its throughput to 58%. To overcome HOL-Blocking problem, many input-queued switch controlled by a scheduling algorithm. Most scheduling algorithms are implemented based on a centralized scheduler which restrict the design of the switch architecture. In this paper, we propose a simple scheduler called Pipelined Round Robin (PRR) which is intrinsically distributed by each input port. We presents to show the effectiveness of the proposed scheduler.

• 한국통신학회논문지
• /
• 제22권1호
• /
• pp.162-172
• /
• 1997

In this paper, we investigated the performance of a binary feedback switch algorithm for the ABR(Available Bit Rate) service in ATM networks. A binary feedback switch is also called EFCI(Explicit Forward Congestion Indication) switch and can be classificed into input cell processing(IP) scheme according to processing methods for the EFCI bit in data-cell header. We proposed two implementation methods for the binary feedback switch according to EFCI-bit processing schemes, and analyzed the ACR(Allowed Cell Rate) of source and the queue length of switch for each scheme in steady state. In addition, we derived the upper and lower bounds for maximum and minimum queue lengths, respectively, and investigated the impact of ABR parameters on the queue length.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권8호
• /
• pp.433-437
• /
• 2000

We fabricated switch module of ATM(Asynchronous Transfer Mode) exchange system with MCM-C(MultiChip Module Co-fired) technology and measured its electrical characteristics. Green tape was used as substrate and Au/Ag paste was used to form the interconnect layers. The via holes were made by drill and filled with metal paste usign screen method. After manufacturing the substrate, chips and passive components were assembled on the substrate. In electrical test, the module showed the output signal of 46.9MHz synchronized with input signal. In the view of substrate size reduction, the area of MCM switch module was 35% of conventional hybrid switch module.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 E
• /
• pp.2239-2241
• /
• 1999

The most important question is how to use which kind of switch in pulsed power generation. There are many kinds of commercial closing switches, which have advantages and disadvantages. The most popular closing switch is the spark gap, but it has a disadvantage in life time, because of erosion of electrodes by arc heating. The Rotary Arc Gap (RAG) switch, especially Walkie-Edgar type RAG switch, was proposed to solve such problems in spark gap. It has a simple and special structure for arc moving caused from self-induced electromagnetic force, because moving arc makes less erosion on the electrodes. In this study we have made an Walkie-Edgar type RAG switch, tested the switching with capacitive energy storage system, and measured rotating arc speed in different peak current.

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

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.929-932
• /
• 2005

We report a pull-up type RF MEMS switch using double electrode without elastic deformation of the cantilever involved in the actuation. At a voltage of 4.5 V, reliable actuations are achieved such that the movable lower contact pad is pulled up by the electrostatic force to make contact with the upper pad. At a frequency of 50 GHz, an insertion loss of 0.7 dB and an isolation of 50.7 dB are obtained from the switch. The measured transient times for switch-on and switch-off are 120 and 80 us, respectively.