Electronics and Telecommunications Research Institute

Sk Telecom Company, Ltd.

University-industry Cooperation Group of Kyung Hee University

Jae-Ick Choi

Dong-Ho Kim

Soon-Ik Jeon

Dong-Uk Sim

Hyung-Do Choi

Chang-Joo Kim

Seong-Ho Son

Soon-Young Eom

Wangjoo Lee

Wang-Joo Lee

Jong-Hwa Kwon

Cheol-Sig Pyo

Ji-Hoon Bae

Sung-Hyun Hwang

Young-Bae Jung

Jung-Sun Um

Byung-Jang Jeong

Byung-Je Lee

Hyuk-Je Kim

Jong-Moon Lee

Sungtek Kahng

Yong-Sik Shin

Byung-Chan Kim

Sung-Jin Yoo

Kwang-Jae Lee

Simonov Nikolai

Han-Phil Rhyu

Byung-Gil Yu

You-Chung Chung

Jeong-Il Kim

Jeongho Ju

Bom-Son Lee

Tack-Gyu Kim

Jeong-ho Ju

Dongho Kim

Geonho Jang

Byung-Woon Jung

Disclosed herein are a method and a system for performing initial ranging in a cognitive radio network The method for performing initial ranging in a cognitive radio network includes: detecting signals received in one or more ranging sections; estimating a tint time offset based on a correlation between subcarrier indices of the signals detected in the one or more ranging sections; estimating a second time offset based on correlations for the signals detected in the one or more ranging sections and a plurality of codes that are predetermined and detecting an initial ranging code among the plurality of codes; and estimating a time offset of a CPE performing initial ranging with the detected initial ranging code using the first time offset and the second time offset that are estimated.

Method and system for performing initial ranging in cognitive radio network

Disclosed are signal transmitting apparatus and method capable of generating polarizations that can be controlled in real time by allocating weights to signals. A signal transmitting method for generating variable polarizations having any vector through a plurality of radiating elements vertical to each other includes: receiving an input signal and separating the input signal into a plurality of separated signals according to the number of radiating elements; and allocating weights for controlling vectors of the variable polarizations to each of the plurality of separated signals, wherein the vectors of the variable polarizations are represented by a vector sum of the plurality of separated signals allocated with weights.

Signal transmitting/receiving apparatus and method for controlling polarization

An antenna system includes: an orthogonal multi-polarization antenna configured to output independent double orthogonal polarizations through two independent input/output terminals; an antenna main control unit configured to perform a polarization control algorithm, collect and analyze information for polarization control, and provide polarization control information; and a polarization control unit configured to perform independent amplitude and phase control with regard to a pair of independent channels connected to the orthogonal multi-polarization antenna, based on the polarization control information received from the antenna main control unit, so that various polarizations are formed.

Antenna system having adaptive polarization control

A CRLH resonator-based band-pass filter includes at least two CRLH resonators. The resonators are connected by capacitive coupling. The resonators includes a microstrip line having input and output ports. The microstrip line includes a first interdigital line serial-connected to the input port, a second interdigital line serial-connected to the output port, a connection line connecting the first and second interdigital lines, and an inductor line parallel-connected to the connection line and provided with a grounded end.

Band-pass filter based on CRLH resonator and duplexer using the same

An image reconstruction apparatus includes: a transmission signal generation unit configured to generate a transmission signal in an image reconstruction region, in order to acquire an image reconstruction value; an electromagnetic wave measurement unit configured to measure electromagnetic waves by receiving the transmission signal; an image reconstruction unit configured to update a parameter by using a matrix of matched system of a Sinc-Gauss-shaped basis function which is allocated to each node of a reconstruction mesh in the image reconstruction region, and generate an image reconstruction value; and an optimization determination unit configured to determine whether the parameter of the image reconstruction unit is optimized or not, and output the image reconstruction value or cause the image reconstruction unit to repetitively perform the calculation, wherein the reconstruction mesh has a grid structure of which the size is larger than that of a forward mesh and equal to the image spatial resolution.

Image reconstruction apparatus and method for reconstructing image of microwave tomography thereof

A small antenna using an SRR structure in a wireless communication system includes: a first radiation unit positioned over a dielectric substrate formed of a predetermined dielectric medium and having a predetermined ring shape; a feed unit positioned over the dielectric substrate and configured to feed a signal to the first radiation unit; a second radiation unit positioned under the dielectric substrate and having a predetermined ring shape; a via formed through the dielectric substrate to connect the first and second radiation units; a ground unit positioned under the dielectric substrate and configured to ground the first and second radiation units; and a metal line unit positioned under the dielectric substrate to connect the second radiation unit and the ground unit. The feed unit includes first and second capacitors which accomplish impedance matching when the signal is fed to the first radiation unit.

Small antenna using SRR structure in wireless communication system and method for manufacturing the same

A metamaterial transmission line for transmitting an electromagnetic wave. The metamaterial transmission line may include a substrate including a substrate configured to include a an upper portion and a lower portion on which a ground plane is formed, a signal line configured to be formed on the substrate, and a defected ground structure configured to include an etched region and two metal portions, wherein the etched region is generated by etching a part of the ground plane and the metal portions extend from the signal line and are disposed on the etched region.

Metamaterial transmission line apparatus and method of implementing the same

Provided are a dipole tag antenna using an artificial magnetic conductor (AMC) for wireless identification and a wireless identification system using the dipole tag antenna. The dipole tag antenna includes: a substrate formed of a first dielectric material; a conductive ground layer formed underneath the substrate; an AMC layer formed on the substrate; the dipole tag antenna mounted on the AMC layer and comprising a wireless identification chip; and the AMC directly mounted on a conductor.

Dipole tag antenna structure mountable on metallic objects using artificial magnetic conductor for wireless identification and wireless identification system using the dipole tag antenna structure

Disclosed are a projecting type hyper-lens and a method of manufacturing the same. The projecting type hyper-lens includes a main lens layer and a substrate layer. A front surface of the main lens layer is recessed. The substrate layer supports the main lens layer. A front central portion of the main lens layer protrudes beyond a surface of the substrate layer. The projecting type hyper-lens allows an object to move towards a front surface of the hyper-lens until a distance between the front surface of the hyper-lens and the object is smaller than a half-wavelength of light, and thus images an object smaller than a half-wavelength of used light. Evanescent waves scattered from an object is used in a manner convenient to a user.

Projecting type hyper-lens and method of manufacturing the same

Provided are a tag antenna for wireless identification and a wireless identification system including the tag antenna. The tag antenna includes: a substrate formed of a first dielectric; a conductive ground layer formed underneath the substrate; an AMC layer formed on the substrate; and a wireless identification chip adhered onto the AMC layer.

Tag antenna structure for wireless identification and wireless identification system using the tag antenna structure

There is provided provided a frequency selective surface (FSS) structure for filtering a single frequency band, including: a plurality of unit cells arranged at a predetermined distance, wherein each of the unit cells includes: a substrate; a circular loop formed on the substrate with a predetermined width and having at least one of meanderingly bent portions, wherein a filtering frequency band is controlled by a length of the circular loop, a width of the circular loop, a distance between the unit cells, and a thickness and dielectric constant of dielectric.

Frequency selective surface structure for filtering of single frequency band

A multi-band internal antenna includes a top patch defining a first loop that defines a space therein and a first opening; a stub provided within the space defined by the first loop; a bottom patch provided below the top patch and having a first section and a second section connected to a feeder part and a shorting part, respectively, the bottom patch defining a second loop and second and third openings, the second and third openings being provided on opposing sides of the second loop so that the first and second sections of the bottom patch are separated from each other; and a first connecting part and a second connecting part connecting a first portion and a second portion of the top patch, respectively, to the first section and the second section of the bottom patch to transmit a signal from the bottom patch to the top patch.

Multi-band internal antenna of symmetry structure having stub

Provided is a tunable magnetic field amplifying device capable of easily adjusting resonance frequencies and tuning usable bands by using discrete elements to vary electric properties of elements that are used for amplifying a magnetic field of a specific microwave band. The tunable magnetic field amplifying device includes a Swiss roll formed by winding a metal sheet coated with a dielectric in a spiral cylinder shape once or several times; and a tunable capacitor connected between an inner sheet of and an outer sheet of the metal sheet for tuning a resonance frequency.

Tunable magnetic field amplifying device

Provided is a method for designing multiband antenna using a genetic algorithm unit linked to an electromagnetic wave analyzing unit and to a computer-readable recording medium for recording a program that implements the method. The multiband antenna designing method can design an antenna having an optimal structure by combining a genetic algorithm, one of global optimization techniques, with a full electromagnetic wave analyzing program Quick Finite Difference Time Domain (QFDTD). The method of the present research includes the steps of: a) at the full electromagnetic wave analyzing unit, analyzing an antenna structure contained in an input file and linking the antenna structure to the genetic algorithm unit; b) at the genetic algorithm unit, generating an initial group that expresses the antenna structure; c) at the genetic algorithm unit, evaluating cost functions by using the antenna structure analysis result; and d) at the genetic algorithm unit, designing an antenna by selecting objects based on the cost functions, mating the selected objects and generating mutants.

Method for designing multiband antenna using genetic algorithm device linked to full electromagnetic wave analyzing device

Disclosed is an electronic active phase control array antenna having two beams which comprises: a first array unit for performing phase shifting on radio waves received via satellite communication, combining them, and generating first beams on the basis of a first phase delay control value according to a first beam frequency; and a second array unit for performing phase shifting on the output value phase-shifted by the first array unit on the basis of a second phase delay control value for compensating for the phase delay difference according to a second beam frequency shifted through the first array unit, and generating second beams.

Electronic active phase control array antenna, method for compensating for direction differences at the antenna, and satellite tracking system and method using the antenna

Growing community of inventors

Daejeon, South Korea

Jae-Ick Choi