• Journal of Power Electronics
• /
• v.15 no.2
• /
• pp.497-503
• /
• 2015

This paper analyses the harmonic pollution to power grids caused by several high-power rectifiers, summarizes the requirements for rectifiers in suppressing grid-side current harmonics and optimizes a new-type of current source PWM rectifier with a hybrid switch. The rectifier with a hybrid switch boasts significant current characteristics and cost advantages in the high-power area. To further enhance the working frequency of the current source rectifier with a hybrid switch for suppressing grid-side harmonics and reducing the inductance size, this paper proposes an optimal control strategy based on space vector. It also verifies that the optimal control strategy based on space vector can reduce the total harmonic distortion of the grid-side current of the rectifier with a hybrid switch via circuit simulation and experimental results.

• Proceedings of the IEEK Conference
• /
• 2000.11a
• /
• pp.441-444
• /
• 2000

This paper covers the performance testing for layer 3 Ethernet switch based on various methodologies by which we can measure essential metrics such as throughput, latency, frame loss rate, and back to back frames. In the first place, layer 2 and layer 3 switch evolution is introduced followed by description of IP packet switching in layer 3 switch. And then, the above test metrics and test methodologies are illustrated as well. At last, we conduct the performance testing for layer 3 switch in case of transmitting packets of 64, 128, 256, 512, 1024, 1280, and 1518 byte size and analyze then results.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.29A no.7
• /
• pp.19-30
• /
• 1992

In this paper, a new large scale ATM switch architecture for Broadband ISDN is presented and its performance is analyzed mathematically. The proposed two-stage ATM switch consists of a sorting network and several unit switches. The proposed switch is self-routing and nonlocking. Its maximum through put is 100% without speed up which other output buffered switch needs. The hardware complexity mainly depends on that of a sorting network, but sorting network is easy to be implemented to VLSI because of its regularity in the structure.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.34S no.1
• /
• pp.1-8
• /
• 1997

A wide class of networking application services, such as video teleconferencing, VOD, LAN bridging, and distributed data processing require multipoint communications. The essential component inteh network to achieve this is a multicast packet switch which is capable of packet replication and switching. In this paper, we propose an efficient mukticast addressing scheme using the smallest number of routing bits which is deterministic lower bound. The new scheme performs all point-to-multipoint connection in radix-2 tree ATM switch like banyan network. Also, we provide a simple radix-2 switch block diagram for achieving our algorithm. And we investigate several addressing schemes for implementing multicasting in radix-r tree ATM switch and evaluate several performance factors, such as complexity of the additional header bits, requirement of the internal speedup and complexity of the major hardware.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.3B
• /
• pp.209-216
• /
• 2003

In this paper, we propose ATM switch structure including AAL type 2 switch which can efficiently transmit low-bit rate data, even if the network has many endpoints. We simulate the architecture of ATM switch fabric that is modeled in computer program and analyze the performance according to offered loads. ATM switch proposed in this paper can support cell switching for all types of AAL cells which consist of AAL type 1, AAL type 2, AAL type 3/4, and AAL type 5 cells. We propose two switch fabric methods; One supports the AAL type 2 cell processing per input port, the other global AAL type 2 cell processing for every input port. The simulation results show that the latter is superior to the former. But the former has a merit for easy implementation and extensibility. The proposed ATM switch fabric is widely applicable to mobile communication, narrow band services over ATM network and wireless ATM as well as general ATM switching fabric.

• Transactions on Electrical and Electronic Materials
• /
• v.17 no.2
• /
• pp.92-97
• /
• 2016

This paper presents design and simulation of wide band RF microswitch that uses electrostatic actuation for its operation. RF MEMS devices exhibit superior high frequency performance in comparison to conventional devices. Similar techniques that are used in Very Large Scale Integration (VLSI) can be employed to design and fabricate MEMS devices and traditional batch-processing methods can be used for its manufacturing. The proposed switch presents a novel design approach to handle reliability concerns in MEMS switches like dielectric charging effect, micro welding and stiction. The shape has been optimized at actuation voltage of 14-16 V. The switch has an improved restoring force of 20.8 μN. The design of the proposed switch is very elemental and primarily composed of electrostatic actuator, a bridge membrane and coplanar waveguide which are suspended over the substrate. The simple design of the switch makes it easy for fabrication. Typical insertion and isolation of the switch at 1 GHz is -0.03 dB and -71 dB and at 85 GHz it is -0.24 dB and -29.8 dB respectively. The isolation remains more than - 20 db even after 120 GHz. To our knowledge this is the first demonstration of a metal contact switch that shows such a high and sustained isolation and performance at W-band frequencies with an excellent figure-of merit (fc=1/2.pi.Ron.Cu =1,900 GHz). This figure of merit is significantly greater than electronic switching devices. The switch would find extensive application in wideband operations and areas where reliability is a major concern.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1673-1675
• /
• 2004

The design, modeling and measurement of RF switch module for GSM applications is presented in this paper. RF switch module is constructed using a LTCC multi-layer switching circuit and integrated low pass filter. Insertion and return loss of the low pass filter were designed less than 0.3 dB and better than 12.7 dB at 900 MHz. The RF switch module contained 10 embedded passives and 3 surface mount components integrated on $4.6{\times}4.8{\times}1.2$ mm, 6-layer multi-layer integrated circuit. The insertion loss of switch module was measured at 900 MHz was 11 dB.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.965_966
• /
• 2009

In this paper, a new soft-switching Two-switch Forward converter topology has been proposed. Compared with conventional two-switch forward converter, the proposed converter employs an auxiliary switch and a clamp capacitor to instead of two reset diodes, not only its duty cycle can exceed 0.5 to achieve wide range input voltage, but also soft switching can be achieved for all switches. Especially, voltage stress across main switches can be clamped at $1/2V_{in}$, voltage stress across auxiliary switch can be clamped at $V_{in}$. In addition, due to clamp capacitor series with the transformer, duty ratio can be extended with equation $V_o=\frac{V_{in}(1-D}D{N}$. Therefore, as a kind of better cost-effective approach, it is very attractive for high input, wide range and high efficiency application.

• ETRI Journal
• /
• v.28 no.1
• /
• pp.84-86
• /
• 2006

This letter presents a small-sized, high-power single-pole double-throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow-wave characteristic, the DGS is used for the quarter-wave (${\lambda}$/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt-connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt-type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.

• Proceedings of the KIEE Conference
• /
• 1998.11b
• /
• pp.594-596
• /
• 1998

In this paper, a path control switch has been developed for self-healing operation in SDH-based transmission system. The proposed switch is suitable for self-healing operations in both an Unidirectional Path Switched Ring and a 2-fiber Bidirectional Line Switched Ring. The path control switch is implemented with $0.8{\mu}m$ CMOS LSI chip. The self-healing operation of the switch is effectively done by the configuration information stored in the registers of the switch. The switch has an AU-3(51.84Mb/s) TSI(Time Slot Interchange) and has 1.25Gb/s throughput. But the higher throughput can be realized by combining two identical switches or more with the parallel architecture.