Electronics and Telecommunications Research Institute

Seong Mo Moon

Ho Yong Ryu

In Bok Yom

Ho Sun Yoon

Dong Hwan Shin

Sun Cheul Kim

Dong Pil Chang

Sung Back Hong

Pyung Koo Park

Young Soo Shin

Jun Han Lim

Soon Seok Lee

Kwang Yong Lee

Sang Yoon Oh

Seungwoo Hong

Beob Kyun Kim

Wan Gyun Choi

Sang Jin Hong

Nam Seok Ko

Jung Sik Kim

Kyeong Ho Lee

Byoung Hak Kim

Byoung Sun Lee

Jong Dae Park

Boo Geum Jung

Byoung-Sun Lee

In Kwon Ju

Jin Cheol Jeong

Seung Woo Hong

Kyoung Soon Kang

Moon-Que Lee

Hyunjoo Kang

Jin Sek Park

Jinseok Park

An I/Q signal generating apparatus and phase shift apparatus using the same are provided, the I/Q signal generating apparatus including: a first resonance circuit whose one end is connected to a first input terminal and whose other end is connected to a first output terminal; and a second resonance circuit whose one end is connected to the other end of the first resonance circuit or a second input terminal, and whose other end is connected to a second output terminal, wherein the first resonance circuit and the second resonance circuit each include a resistor, a capacitor connected in parallel with the resistor, and an inductor connected in a form of a cross between the resistor and the capacitor.

In-phase/quadrature-phase generating device and phase shift device using the same

A master reference oscillator system is provided. The master reference oscillator system includes a plurality of reference oscillators and a hybrid matrix receiving signals from the plurality of reference oscillators and outputting a plurality of output signals having the same signal magnitude, wherein at least two output signals among the plurality of output signals may have a phase difference.

Master reference oscillator system

Disclosed is a dual-band phase shifter in which series/parallel resonance circuits are applied to a polyphase filter to implement a phase shifter, which is a core block of a multi-channel RFIC for implementing a phased array antenna system. The dual-band phase shifter may be configured by converting a capacitor (C) of an LC circuit or a CL circuit in the RFIC into a series resonance circuit and converting an inductor (L) thereof into a parallel resonance circuit, so that a signal generator operating in one frequency band can operate in a dual-band.

Dual-band 360 degree phase shifter using series/parallel resonance circuit for phased array antenna system

Provided is a FET resistive frequency mixing device having improved RF-LO and IF-LO isolations. The frequency mixing device includes: a field effect transistor (FET), a local oscillation matching circuit connected to a gate of the FET to transfer a local oscillation signal to the gate of the FET, a gate biasing circuit connected to the gate of the FET, a radio frequency (RF) matching circuit having a first terminal connected to a drain side of the FET and a second terminal serving as a RF terminal to receive or output a RF signal, an intermediate frequency (IF) matching circuit having a first terminal connected to the drain side of the FET and a second terminal serving as an IF terminal to receive or output an IF signal, and a series resonance circuit providing a path from the drain of the FET to ground for the local oscillation signal.

Frequency mixing device

Provided is a microwave filter system having a feedback structure. The microwave filter system may include an input hybrid coupler configured to output first output signals having a phase difference with respect to an input signal; filters disposed to be in parallel with an output end of the input hybrid coupler, and configured to filter the first output signals; and an output hybrid coupler configured to output second output signals having a phase difference with respect to each of signals filtered through the filters. An output signal of the output hybrid coupler is applied to an input end of the input hybrid coupler along a feedback path.

Microwave filter system including feedback structure

Disclosed are a method of controlling a process based on a network operation mode and an apparatus therefor. A process controlling method performed in a network device includes determining an operation mode for an operating system of the network device, determining an entity for controlling a process based on the determined operation mode, and controlling the process through the determined entity. According to the present invention, it is possible to control a process lifecycle through the same interface regardless of the network operation mode.

Method for controlling process based on network operation mode and apparatus therefor

A method for transiting an operation mode of a routing processor is provided, which allows each routing processor in a packet processing system to be transited among a slave operation mode, a slave stand-by mode, a master stand-by mode, and a master operation mode to allow the packet processing system to normally operate even though a failure occurs in the routing processor that is set in the master operation mode, a new routing processor is added, or the routing processor set in the master operation mode is initialized.

Method for transiting operation mode of routing processor

Disclosed herein are an apparatus and method for displaying images. The apparatus includes a first image output unit, a second image output unit, an image signal selection unit, and an image display unit. The first image output unit is set to master operation mode, and outputs an image signal to be displayed. The second image output unit is set to slave operation mode, and, if the first image output unit has failed, is switched to master operation mode and then continuously outputs the image signal or a new image signal. The image signal selection unit compares the IP source address of a received master message with previously stored address information, and then selects the image signal that is received from the first image output unit or the second image output unit that has a matching address. The image display unit displays the selected image signal.

Apparatus and method for displaying images

Disclosed is a low phase shift voltage variable attenuator. The low phase shift voltage variable attenuator may include: a first directional coupler including a first input terminal in which a signal is input, a first isolation terminal connected to a ground power source through a termination resistor, a first coupling terminal, and a first through terminal; a second directional coupler including a second input terminal through which an attenuated signal, which is the attenuated input input signal, is output, a second isolation terminal connected to a ground power source through a termination resistor, a second coupling terminal, and a second through terminal; and a signal attenuating unit connected to the first coupling terminal, the first through terminal, the second coupling terminal, and the second through terminal, and configured to attenuate a signal transmitted through the first directional coupler to transmit the attenuated signal to the second directional coupler.

Low phase shift voltage variable attenuator

Disclosed are a system for managing virtual private networks (VPNs) includes: terminals configured to transmit user data; a manager configured to transmit information for concealing networks and managing the VPNs; border gateways configured to decrypt the user data and perform a network address translation (NAT) procedure and a filtering procedure on the decrypted user data based on the information; and servers configured to receive the user data subjected to the NAT procedure and the filtering procedure, wherein the filtering procedure is a procedure discarding the user data to be transferred to the servers that are not allowed so as to allow the terminals to access only the allowed servers, the NAT procedure is a procedure changing an Internet protocol (IP) address used in a first network to an IP address used in a second network, and the first network and the second network are different networks.

System for managing virtual private network and method thereof

In a plurality of virtual tunnel routers including a first virtual tunnel router and a second virtual tunnel router, the first virtual tunnel router and the second virtual tunnel router request virtual network prefix information from a tunnel mapping controller. When the tunnel mapping controller generates virtual network prefix information of the first virtual tunnel router and the second virtual tunnel router, respectively, and transmits the same along with information of a list of adjacent virtual tunnel routers, the first virtual tunnel router and the second virtual tunnel router create a tunnel. With the tunnel established, the virtual network prefix information received by the first virtual tunnel router and second virtual tunnel router, respectively, is linked so that direct communication can be performed between the first virtual tunnel router and the second virtual tunnel router.

Method of network-based communication in virtual network environment

The invention relates to a method and an apparatus for controlling seamless handover between heterogeneous networks based on IPv6 over IPv4 tunneling. When IPv6 service is provided using tunneling in an IPv4 based network environment, handover of a mobile terminal between different networks is achieved through switching of an active tunnel and a standby tunnel, and thus handover between different networks is facilitated and data loss is prevented to secure continuity of service provided to the mobile terminal even when the mobile terminal hands over to a heterogeneous network.

Apparatus and method of controlling seamless handover between heterogeneous networks based on IPv6 over IPv4 tunneling mechanism

A multiport amplifier modulates a reference quadrature phase shift keying (QPSK) signal using an input RF signal to an input hybrid network, generates a plurality of binary phase shift keying (BPSK) signals by demodulating RF signals that are amplified by a plurality of power amplifiers, detects an amplitude error and a phase error of two corresponding amplified RF signals by comparing a QPSK signal that is generated by coupling two RF signals having a phase difference of 90&#xb0; among the plurality of BPSK signals with a reference QPSK signal, and compensates the detected amplitude error and phase error.

Apparatus for calibrating amplitude and phase errors, multiport amplifier including the same, and method of amplifying the multiport amplifier

The present invention relates to tunneling an IPv6 packet through an IPIv4 network. In using a tunneling method upon transmitting an IPv6 packet in an IP network, when destination nodes desired to be communicated are located within the same IPv6 prefix network, IPv6 prefix information is added for the management of a tunnel entry. Hence, tunneling information on terminals located within the same IPv6 prefix network can be managed as one tunnel entry. Accordingly, the time consumed when retrieving a tunnel entry can be reduced.

Tunneling IPv6 packet through IPv4 network using a tunnel entry based on IPv6 prefix and tunneling IPv4 packet using a tunnel entry based on IPv4 prefix

A device for providing forwarding and QoS information in a flow based network environment acquires first information and second information from a flow table therein on the basis of status information of a predetermined flow in order to provide dynamically updated information in a flow based network environment. When it is determined that first information and second information acquired based on a route ID of a series of information are updated, the flow table is updated and the updated information is provided.

Growing community of inventors

Daejeon, South Korea

Seong Mo Moon