Electronics and Telecommunications Research Institute

Seoul National University

Industry-academic Cooperation Foundation, Chosun University

Kwang Seon Kim

Woo Jin Byun

Min Soo Kang

Bong Su Kim

Myung Sun Song

Bong-Su Kim

Hui Dong Lee

Mi Kyung Suk

Jae Ho Jung

In Kui Cho

Je Hoon Yun

Jung Ick Moon

Seong Min Kim

Seung Hyun Jang

Jung Nam Lee

Sun Woo Kong

Yong Heui Cho

Sang H Chai

Tae Jin Chung

Jin Ho Lee

Young Kyun Cho

Tae Joong Kim

Seok Bong Hyun

Jae Ick Choi

Jong Soo Lim

Jung Bin Kim

Kwang Chun Lee

Kwangchun Lee

Seunghyun Jang

Myung Don Kim

Heon Kook Kwon

Kee Soo Nam

Sunwoo Kong

Young Seung Lee

Yong Seo Koo

Young S Koo

Woo Jin Byung

Yeo H Kim

Hung Chul Park

Jeehoon Park

Jee Hoon Park

Sun Soo Oh

An array antenna capable of steering a beam in a first communication node of a wireless communication system may comprise: a plurality of single antennas each capable of variably adjusting a beam steering direction; a plurality of beamforming control units each of which is connected to each of the plurality of single antennas to control a beamforming operation of each of the plurality of single antennas; and an array antenna control unit connected to the plurality of beamforming control units to control a beamforming operation of the entire array antenna, wherein the plurality of single antennas are arranged in a cylindrical shape and are installed to face a direction opposite to a central direction of the cylinder shape, and the array antenna is configured to steer a beam to a predetermined area around the first communication node through at least one single antenna among the plurality of single antennas.

High frequency-based array antenna and communication method therefor

An array antenna system, and a calibration method and apparatus thereof are provided. The calibration method includes measuring a signal loop including mutual coupling between antennas included in an array antenna, calculating a ratio of a reception (RX) signal received by each antenna to an RX signal received by a reference antenna of the array antenna based on a result of the measuring, and performing calibration of the array antenna based on the ratio.

Array antenna system, and calibration method and apparatus thereof

A direct current-to-direct current (DC-DC) converter providing multiple operation modes includes a buck power stage configured to lower an input voltage, a boost power stage configured to increase the input voltage, and a multi-mode controller configured to control the buck power stage and the boost power stage, wherein the multi-mode controller is configured to generate a signal to control the buck power stage and the boost power stage according to the input voltage and an output voltage, and control the buck power stage and the boost power stage using the signal.

DC-DC converter providing multiple operation modes using multi-mode controller

An amplifier may comprise first and second matching networks; first and second transistors; and a transformer including first to third inductors. Also, a gate and a source of the first transistor are connected to the first matching network, one end of the first inductor is connected to a drain of the first transistor, the other end of the first inductor is connected to a source of the second transistor, one end of the second inductor is connected to a gate of the second transistor, the other end of the second inductor is grounded, one end of the third inductor is connected to a drain of the second transistor, and the other end of the third inductor is connected to the second matching network.

Amplifier for reusing current by using transformer and method thereof

Disclosed are a method and apparatus for canceling self-interference signals in a communication system. A first communication node includes a signal transmission unit configured to generate a first RF signal, an antenna module configured to transmit the first RF signal generated by the signal transmission unit and receive a second RF signal from a second communication node, a signal reception unit configured to process the second RF signal and a self-interference signal caused by the first RF signal, and an SIC circuit configured to cancel the self-interference signal. The SIC circuit includes a DSIC circuit for canceling the self-interference signal in a digital domain and an ASIC circuit and an HSIC circuit for canceling the self-interference signal in an analog domain. Accordingly, the performance of the communication system may be enhanced.

Method and apparatus for canceling self interference signal in communication system

A transceiving apparatus may comprise a radiator emitting a beam; a receiver receiving a beam; a first sub-reflector which is provided to face the radiator and changes an orbital angular momentum (OAM) mode order of a beam; a second sub-reflector which is provided to face the receiver and changes an OAM mode order of a beam differently from the first sub-reflector; and a main reflector which is provided to face the first sub-reflector and the second sub-reflector.

Transceiver in wireless communication system

Disclosed are a method for signal modulation based on pulse density modulation and an apparatus therefore. The method for signal modulation is performed in an apparatus for modulating a signal based on pulse density modulation and includes performing pulse density modulation on an analog signal input to the apparatus through a pulse density modulator of the apparatus, converting a bandwidth of the pulse density modulated signal into a bandwidth required for the apparatus through a correlative encoder of the apparatus, transmitting the bandwidth converted signal to a radio frequency (RF) unit of the apparatus based on an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter of the apparatus, filtering a frequency band of the bandwidth converted signal and outputting the frequency band filtered signal via the RF unit.

Method for signal modulation based on pulse density modulation and apparatus therefor

The present disclosure relates to a wireless communication apparatus capable of increasing throughput using MIMO in an LOS environment and a method for the same. A wireless communication apparatus based on the LOS-MIMO technique may comprise a multi-link configuration unit, a frequency response correction unit, a signal compensation unit, and a feedback unit. In the apparatus, an additional LOS-MIMO equalizer is used at the front of an LOS-MIMO estimator and a coding unit in order to compensate in-band frequency characteristics of frequency response characteristics estimated by the LOS-MIMO estimator and a signal channel estimator, whereby the LOS-MIMO estimation performance can be remarkably enhanced. Also, precise separation of multiplexed signals through the above-described LOS equalizer can make it possible to increase transmission capacity by using the LOS-MIMO which can be applied to high-order mode (e.g., over 16 quadrature amplitude modulation (QAM)) digital communications.

Wireless communication apparatus for increasing throughput using MIMO in LOS environment and method therefor

An apparatus for orbital angular momentum (OAM) mode combination and an antenna apparatus for multi-mode generation are provided. The apparatus for OAM mode combination includes three input ports configured to receive independent OAM mode signals, four output ports configured to output OAM mode signals with the same or different phase delays; and a circuit element configured to simultaneously combine or distribute the OAM mode signals by controlling phases of output signals output through the four output ports to be different depending on the OAM mode signals received through the input ports.

Apparatus for OAM mode combination and antenna apparatus for multi-mode generation

Disclosed is a circular array antenna. The circular array antenna includes: an input/output unit receiving electromagnetic waves from a transmitter and distributing the received electromagnetic waves to the antenna; a primary feeder connected with the input/output unit and placed at the center of the circular array antenna; a plurality of secondary feeders radially connected to the primary feeder; a plurality of patch units connected to the respective secondary feeders to generate an electric field radially; and a plurality of length controllers formed at terminals of the respective secondary feeders in a direction to extend the lengths of the respective secondary feeders, of which the lengths are controllable.

Circular array antenna

Provided are a multi-input multi-output system which overcomes a disadvantage that optimal receiving performance cannot be maintained according to an installation environment and a performance change of a receiver when a receiving module is configured by using a fixed attenuator and a fixed phase in a line-of-sight multi-input multi-output system configuration and analogously controls an interference removing module of a receiver including a variable attenuator and a phase shifter which are controllable to enhance a receiving performance and increase frequency efficiency, in order to maximize a signal-to-interference ratio of each path and an operating method thereof.

Method for enhancing performance of multi-input multi-output system on line-of-sight

The present invention provides an array antenna apparatus for a rotation mode, a wireless communication terminal, and a method thereof. The apparatus according to the exemplary embodiment includes an antenna array including a plurality of antenna elements; and a control unit which determines an antenna pattern in accordance with a transmission/reception characteristic of a signal and assigns a weight to antenna elements in a position corresponding to the determined antenna pattern on the antenna array to implement a rotation mode antenna based on the antenna element to which the weight is assigned.

Array antenna apparatus for rotation mode, and wireless communication terminal and method

The present invention relates to a reception apparatus. The reception apparatus includes a plurality of reception antennas; and a signal processing unit configured to use reception characteristic of the plurality of reception antennas, wherein the signal processing unit comprises a channel estimation unit configured to respectively estimate a channel response matrix of each signal received via the plurality of reception antennas, and a coding unit configured to define a coding matrix based on an inverse matrix of the estimated channel response matrix, and to obtain a final output signal corresponding to each reception antenna by applying the coding matrix to each received signal.

Reception apparatus of multi input multi output system and reception signal processing method

A method for use with a reflectarray antenna for wireless telecommunication is described. The method involves providing a reflectarray antenna, and adjusting a phase of a scattered field of the reflectarray antenna for generating different radiation patterns for angular mode-based multiplexing. The reflectarray antenna includes a ground plane, a dielectric substrate attached on the ground plane; and a first antenna patch formed on one side of the dielectric substrate. Further, the reflectarray antenna includes a second antenna patch formed adjacent to the first antenna patch with a separation area therebetween; and a phase adjustment member disposed in the separation area. The phase of the scattered field of the antenna is adjusted by changing a DC voltage of the phase adjustment member.

Method for use with a reflectarray antenna for wireless telecommunication

Provided is an apparatus for calibrating a transmission path, the apparatus including one or more couplers to separate, by one or more paths, one or more input signals input from an input terminal of one or more antennas, a power detector to detect amplitude of one or more path signals separated by the one or more paths, a power distributor to distribute any one of the one or more path signals, one or more mixers to mix a distribution signal distributed by the power distributor with the one or more path signals, a low-pass filter to remove a high-frequency component of a mixed signal mixed by the one or more mixers; and a voltage detector to detect amplitude of one or more filter pass signals with the high-frequency component removed.

Apparatus and method for calibrating transmission path

Growing community of inventors

Daejeon, South Korea

Kwang Seon Kim