• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.105-109
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• 2005

A compact antenna switch module for GSM/DCS dual band applications based on multilayer low temperature co-fired ceramic (LTCC) substrate is presented. Its size is $4.5{\times}3.2{\times}0.8 mm^3$ and insertion loss is lower than 1.0 dB at Rx mode and 1.2 dB at Tx mode. To verify the stability of the developed module to the process window, each block that is diplexer, LPF's and bias circuit is measured by probing method in the variation with the thickness of ceramic layer and the correlation between each block is quantified by calculating the VSWR In the mean while, two types of bias circuits -lumped and distributed - are compared. The measurement of each block and the calculation of VSWR give good information on the behavior of full module. The reaction of diplexer to the thickness is similar to those of LPF's and bias circuit, which means good relative matching and low value of VSWR, so total insertion loss is maintained in quite wide range of the thickness of ceramic layer at both band. And lumped type bias circuit has smaller insertion itself and better correspondence with other circuit than distributed stripline structure. Evaluated ceramic module adopting lumped type bias circuit has low insertion loss and wider stability region of thickness over than 6um and this can be suitable for the mass production. Stability characterization by probing method can be applied widely to the development of ceramic modules with embedded passives in them.

• Progress in Superconductivity and Cryogenics
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• v.13 no.1
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• pp.31-35
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• 2011

A Hybrid Fault Current Limiter(FCL) which has more advantages in fast response and thermal characteristics than a simple resistive FCL had been proposed by our group. The Hybrid FCL consists of a resistive FCL for the magnitude of the first peak of fault current, and a fast switch for detecting fault current and generating the repulsive force within a cycle in fault situation. In ideal case, the impedance of the fast switch wound with two other kinds of HTS tape is negligibly zero in normal operation. But, during the fault situation, each HTS tape has different quench characteristics because of asymmetric current distribution. And this phenomenon causes effective flux and this flux opens the switch through the repulsive force applied to a metal plate of the fast switch. The magnitude of the repulsive force affects the switching characteristics of the fast switch. It should be large enough to raise the metal plate up. Otherwise the arc re-out break which are caused by not enough repulsive force to raise the metal plate up can cause unintended operation of the fast switch. In this paper, the numerical calculation of the repulsive force applied to the metal plate of the fast switch in various combinations of HTS tapes was performed by using the short-circuit test and finite element method.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.714-716
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• 2001

This paper is about the characteristic analysis of a heater-trigger HTS switch. It is composed of a BSCCO tape wire and a heater as a thermal quench source. To minimize the heat flow to the liquid nitrigen, the epoxy was used around them. The heater-trigger switch operates in the process that the HTS tape is thermally quenched by the current flowing through the heater. Since the switch works in coolant, it needs to be designed by the accurate thermal characteristic analysis. Here, we focus on FEM for it.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.8
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• pp.433-437
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• 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.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.59-67
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• 2009

With the development of high-cost vehicle detectors, low-cost detectors have also been studied due to the advantage that more detectors are provided within limited budgets. This study proposed a method to estimate vehicle speeds using vehicles' track data from auto manufacturers and time stamps obtained when vehicles' tires pass an inclined sensor (here, a tape switch sensor). In speed estimation, small vehicles and large vehicles is distinguished according to the ratio of time stamps for a wheelbase and a rear track obtained from a tape switch sensor. In particular, speed estimation can be adjusted through a parameter to determine vehicles' size so as to take into account location properties such as vehicles' classification ratio. The low-cost vehicle detector with an inclined sensor proposed in this study is expected to be widely utilized to monitor traffic conditions thanks to low cost.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.9 s.351
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• pp.120-127
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• 2006

In Korea the vehicle enforcement system(VES) detects speeding vehicle using two inductive loop detectors. And the speed reliability of theirs are evaluated through the analysis of image frame which is captured from video camera. This method is validated to evaluate VES on Korea Laboratory Accreditation Scheme(KOLAS) but it needs much time and expense for the analysis of image frame. Because the number of VES are increasing rapidly, the requirement of new evaluation method is necessary. On this paper, the tape switch sensor as a substitution of existing method was introduced and its application on the site are discussed. On the site test we compared the tape switch sensor on the speed measurement of vehicle with the video image frame. As a result we have founded that the tape switch sensor is evaluated to be feasible system on site in respect to measure the overspeed vehicle.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.79-86
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• 2008

This paper proposed the appropriate installation angle of skewed sensors for measuring vehicle wandering data, which are collected to figure out the location of dynamic weight of a moving vehicle on roadways. We developed a device using tape-switch sensors and a computer program and collected vehicle wandering data with the device and probe vehicles. As a result, the steeper the skewed sensor was installed, the lower the error was shown. However, we could not collect proper data when a skewed sensor was set up higher than $30^{\circ}$ due to tandem axle. Therefore, this study suggested the appropriate angle of skewed sensors as a degree of $20^{\circ}$ to $25^{\circ}$ for gathering wandering data.

• Progress in Superconductivity and Cryogenics
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• v.16 no.1
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• pp.32-35
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• 2014

Recently, many researches on the system of superconducting power supply and superconducting magnetic energy storage (SMES) using high temperature superconducting (HTS) tapes has been progressed. Those kinds of superconducting devices use the heater trigger switches that have a control delay problem at moments of heating up and cooling down. One way to reduce the time delay is using a different HTS tape at trigger part. For example, HTS tape having lower critical temperature can reduce time delay of heating up and heating down stage for heater trigger operation. This paper deals with resistances joint with different kinds of HTS tapes which have different properties to verify usefulness of the suggested method. Three kinds of commercial HTS tapes with different specifications are selected as samples and two kinds of solders are used for comparison. Joint is performed with temperature and pressure controllable joint machine and the joint characteristics are analyzed under the repeatable conditions.

• Progress in Superconductivity and Cryogenics
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• v.7 no.4
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• pp.28-31
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• 2005

To verify the feasibility of bifilar winding type superconducting fault current limiter (SFCL) using BSCCO tape, two types of magnets were fabricated and tested by short-circuit in this research. Even if the FCL using high Tc superconducting (HTS) tape has zero resistance in normal state, it needs to be wound as a bifilar winding for zero inductance. Solenoid type and pancake type bifilar winding magnets are designed and fabricated with the same length of BSCCO tape. The test system consists of AC power supply, transformer, fault switch, load and bifilar winding magnet. The applied AC voltages during fault duration, 0.1s, were from 0.5V to 20V. The test results without bifilar winding magnet were compared with those with each type magnets. The test results include voltage against magnet, transport current and generated resistance curve. Thermal stability, the recovery time, was studied from the results of two type magnets. The pancake type was the most effective to limit fault current but the solenoid type was thermally the most stable. From this research, short-circuit characteristics of the two types were obtained.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.4
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• pp.30-39
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• 1998

Currently, LAMA(Local Automatic Message Accounting) is a billing mechanism which is being used for billing process, in which billing dat is written on MT(Magnetic Tape), collected at each regional billing center and then processed once a month. However, in order to prepare further development of telecommunication network and future new services, computerization of billing process and new daily billing processing system are urgently needed. Therefore Korea Telecom had developed a CAMA (Centralized Automatic Message Accounting) system for M10CN switch. In the CAMA system, billing data generated in switches is transfered on-line using approproate protocols and various transmission media and immediately processed. The CAMA system for M10CN switch consists of three parts such as ED (Extraction Device), TD(Transmission Device) and HC(Host Collector). The system also has redundancy to maintain continuance and confidence of system operation.