Electronics and Telecommunications Research Institute

Korea Telecom

Korea Telecommunication Authority

Tae Goo Choy

Sang Seok Lee

Dong Suk Jun

Jin Woo Hahn

Seung Ho Ahn

Myung Yung Jeong

Chang Hwa Lee

Dong Young Kim

Bon Hee Koo

Oh Gone Chun

Yark Yeon Kim

Hong Yeol Lee

Duk Jun Kim

Gee Pyeong Han

Sang Ho Park

Gunn Hwang

Seok-Hwan Moon

Sang Kuk Choi

Ho Gyeong Yun

Meyng Soo Kim

Dong Pil Shin

Meyung Soo Kim

Hong Joon Chun

Myung Soo Kim

Joong Moo Park

Suk J Lee

Han Dae Cho

A S/N enhancer using the magnetostatic wave signal. The S/N enhancer comprises a balun coupler for dividing an input signal into a first and second signals having the same power, the second signal having the phase difference of 180 degree with respect to the first signal; a saturation magnetostatic wave filter for receiving the first signal output from the balun coupler, converting that into a magnetostatic wave signal, and oppositely converting the magnetostatic wave signal, wherein the power of the magnetostatic wave signal is saturated if the first signal has the power of equal to and more than that of a noise signal; a delay line having the linearity to transmit the second signal output from the balun coupler; and a power synthesizer for synthesizing the respective signals output from the saturation magnetostatic wave filter and the delay line.

S/N enhancer

A S/N enhancer using the magnetostatic wave signal. The S/N enhancer comprises a balun coupler for dividing an input signal into a first and second signals having the same power, the second signal having the phase difference of 180 degree with respect to the first signal; a saturation magnetostatic wave filter for receiving the first signal output from said balun coupler, converting that into a magnetostatic wave signal, and oppositely converting the magnetostatic wave signal, wherein the power of the magnetostatic wave signal is saturated if the first signal has the power of equal to and more than that of a noise signal; a linear magnetostatic wave filter for receiving the second signal from said balun coupler, converting that into a magnetostatic wave signal, and oppositely converting the magnetostatic wave signal, wherein the received second signal is converted into the magnetostatic wave signal having an energy linear to the power of the input signal; and a power synthesizer for synthesizing the respective signals output from said saturation magnetostatic wave filter and said linear magnetostatic wave filter.

MgAl2O4-system dielectric ceramic composition and method for fabricating dielectric ceramic using the same

A heat pipe having a woven-wire wick and a straight fine-wire wick is disclosed. The heat pipe can be easily manufactured and improve a thermal performance of the heat pipe. The heat pipe includes a pipe container; a straight fine-wire wick located in the pipe container, wherein the straight fine-wire wick has a porosity; a woven-wire wick having a plurality of groups of wires spirally woven to form a substantially cylindrical wick, for contacting the straight fine-wire wick to an inner wall of the pipe container, wherein when the woven-wire wick is forced radially and inwardly in order for the woven-wire wick to be inserted into the pipe container, the woven-wire wick has restoration forces in a radial and outward direction from axis of the woven-wire wick and is tightly contact with the inner wall of the pipe container, and wherein ends of the straight fine-wire wick and the woven-wire wick are fixed to ends of the pipe container.

Heat pipe having woven-wire wick and straight-wire wick

A duplexer using a dielectric block and having stepped impedance resonators is disclosed. The duplexer comprising open ended resonators arranged in a front side of the dielectric block, shorted resonators arranged in a rear side of the dielectric block, first grooves for controlling receiving coupling at the receiving filter, second grooves for controlling transmitting coupling at the transmitting filter, and a plurality of recesses formed at the bottom of the dielectric block, extending from a first aperture of the open ended resonators to a second aperture of the shorted resonators. The duplexer according to this invention is miniaturized by excluding external elements and has excellent attenuation characteristics, and is being manufactured by simple processes.

Duplexer with stepped impedance resonators

A compliant press-fit pin for electrically coupling a first board to a second board via a plated through hole formed in the second board, includes: an upper part for electrically fixing the first board; a lower part for electrically coupling the first board to a third board via the plated through hole formed in the second board; and a press-fit part located between said upper part and said lower part and containing a fixed beam and a compliant cantilever beam, for electrically coupling the first board fixed to said press-fit part to the second board, wherein the fixed beam and the compliant cantilever beam provide a retention force against a wall of the plated through hole, thereby electrically press-fitting the compliant press-fit pin into the plated through hole, when said press-fit part is inserted into the plated through hole.

Compliant press-fit pin having compliant cantilever beam

A dielectric ceramic composition for a microwave device including MgTiO.sub.3 and CaTiO.sub.3 as a main component and a Li.sub.2 CO.sub.3 as a sub-component is provided. The composition being expressed as follows: (94MgTiO.sub.3 -6CaTiO.sub.3)+xLi.sub.2 CO.sub.3 (mol %), where 0.2.ltoreq.x.ltoreq.0.8 (mol %). Therefore, it is capable of increasing a quality factor and decreasing a sintering temperature by adding a new component and effectively reproducing the above-described dielectric characteristic.

Dielectric ceramic composition of microwave MGTIO.sub.3 CATIO.sub.3

A method of ferrules used in an optical connector for connection and short-circuit of making multichannel optical signals. Heretofore, many fiber receiving holes have been arranged along a line at regular intervals with tolerance amounting to less than 1 micron. 10 and connect two ferrules, a precisely processed cylindrical metal guide pin under 1 micron, precise pitches formed in ferrules and a metal pin guide hole are used, Consequently, it has been necessary to maintain a high degree of precision. The present invention maintains a high degree of precision by reverse direction connection dependent merely on a predetermined height a reference plane. The reference plane is formed by relatively easy plane processing as the method of maintaining precise height and directivity of flow is added to the inside of a mold.

Manufacturing method of multifiber connector ferrule for ribbon-type

An isolator/circulator can keep a size of a 3-way asymmetric propeller resonator and intensity of magnetism, control the preferred frequency, and improve the insertion loss and isolation characteristic due to reducing the ferrite usage region on the maximum, extend the wide band without the external wide band extension, finally to miniaturize, reduce the fabricating cost by means of a simple fabrication. A microstrip/stripline isolator/circulator having a propeller resonator can be used for the device protection and impedance matching of a system and terminal in a transfer communication, personal communication, CT and satellite communication.

Microstripline/stripline isolator/circulator having a propeller resonator

A microwave dielectric ceramic composition is fabricated by adding one selected from a material containing Ba and a material containing Sr or a mixture of a material containing Ba and a material containing Sr to a composition formed of 25.about.43 wt % of TiO.sub.2, 39-57 wt % of ZrO.sub.2, and 7-28 wt % of SnO.sub.2 as an additive, wherein the additive is added by 0.2.about.8.0 wt % based on the total amount of the composition, and is capable of implementing a high dielectric constant and quality factor by sintering at a temperature of 1250.about.1400.degree. C.

Microwave dielectric ceramic composition

The present invention relates to a microwave filter, having U-type resonators, which passes a desired frequency signal and removes an undesired frequency signal when used in a high frequency antenna circuit for wireless communication systems. In accordance with the trend of reducing communication system terminals, it is required to reduce a high frequency filter. The high frequency filter is required to attenuate signals very sharply at the stop band especially near to a passband transmitting and receiving frequency, so as to improve the efficiency of the frequency. The filter may be reduced in weight by forming U-type resonators instead of straight-type resonators. Excellent attenuation characteristics may be achieved at the stop band lower than the passband, using the difference of the characteristic impedance between the open end portion and the shorted portion of the resonator by forming the coupling control grooves at the outer walls of the dielectric block.

Microwave filter with U-type resonator

A compound testing machine for testing mechanical properties used for an optical connector does not additionally have each testing machine for each of mechanical properties (such as a tensile force including both a straight pull and a side pull, a flex, a twist and an impact) in testing a mechanical property between optical connectors and other mechanical property between optical fibers of the optical connectors, and includes only one testing machine for simultaneously testing various mechanical properties in order to enhance a test machine's efficiency. The compound testing machine includes: a rotation part which includes a test specimen fixing portion for fixing a test specimen, a cable connected to the test specimen, and a load applying portion connected to the cable so as to provide a predetermined load to the test specimen, receives a driving force of an electric motor, and measures a tensile force and a flex; and an impact testing part which is mounted to one side of the rotation part, drops the test specimen while freely adjusting a height of the test specimen, and thus performs an impact test.

Compound testing machine for testing various mechanical properties used

A chip type capacitor with a multi-layer structure comprising a plurality of inner electrodes classified into two groups one being used as parts of signal lines and the other being connected to grounded lines. Each of the inner electrodes for radio frequency passages has a pair of inwardly extending recesses adapted to make current flows generated in the inner electrode by radio frequency noise be opposite to each other. Each of at least two grounded inner electrode pairs is interposed between vertically adjacent inner electrodes used as parts of signal lines. The inner electrodes of each pair are connected to ground terminals, respectively, and have a shape formed by removing one protruded grounding portion from a cross shape. With this arrangement, the current flows in the inner electrodes of each pair are opposite to each other, so that electromagnetic fields generated by the current flows through the inner electrodes offset each other, thereby enabling the equivalent serial resistance at radio frequency to be decreased and the inductance to be decreased.

Chip type capacitor for removing radio frequency noise

A rotation and alignment device for assembling of an optical fiber connector with a lower connection loss. This device image-processes the distribution of optical intensity of light emitted from an end surface of an optical fiber of a ferrule and derives an optical peak intensity point of the end surface of the optical fiber such that the point is placed in a predetermined region of a rectangular coordinate system. This device comprises a rotation and marking part for controlling a rotational position of a marker with respect to the ferrule and marking the optical peak intensity point on an outer surface of the ferrule. A ferrule fixture part is coupled to the rotation and marking part and fixes the ferrule such that the outer surface of the ferrule is marked with the optical peak intensity point by the marker. A vertical supporting part supports the rotation and marking part and the ferrule fixture pat. An optical system and fiber alignment part is mounted on the support rail part and magnifies and aligns the end surface of the optical fiber of the ferrule. The support rail part assures the rotation and marking part and the optical system and alignment part of a desired horizontal location.

Growing community of inventors

Daejeon, South Korea

Tae Goo Choy