Electronics and Telecommunications Research Institute

Moo Jung Chu

Jyung Chan Lee

Min Soo Kim

Hee Sang Chung

Yong Sung Eom

Won Kyoung Lee

Kwang Joon Kim

Sun Hyok Chang

Mi Hee Jung

Hyun Jae Lee

Seung Youl Kang

Kyoung Ik Cho

Jong-Hyun Lee

Hyun Seo Kang

Kwang-Seong Choi

Dong Suk Jun

Sang Soo Lee

Han Hyub Lee

Jong Tae Moon

Seok-Hwan Moon

Hyun-cheol Bae

Jin Soo Han

Ki Ho Han

Seung Kwan Kim

Dong Han Lee

Jun Ki Lee

Soo Young Oh

Yong Bae Lee

Provided is a power conversion system. The system includes a DC bus line including a common terminal, a power generation device configured to provide DC power to the common terminal, a first inverter configured to convert a first input power provided from the common terminal into a first AC power and output the first AC power, and a second inverter configured to convert a second input power provided from the common terminal into a second AC power in response to the first input power being greater than a first threshold power while the first inverter operates and output the second AC power.

Power conversion system and operation method thereof

Provided is an inverter system capable of more economically and efficiently performing photovoltaic power generation by automatically switching an integrated operation and an independent operation of inverters according to voltage values and current values of photovoltaic panels without a separate communication function. The inverter system for photovoltaic power generation according to an exemplary embodiment of the present disclosure is an inverter system which changes direct current power output from a first photovoltaic panel and a second photovoltaic panel to alternating current power and includes: a first inverter and a second inverter, in which all of the outputs of the first and second photovoltaic panels are applied to the first inverter, or the output of the first photovoltaic panel is applied to the first inverter, and the output of the second photovoltaic panel is applied to the second inverter according to output values of the first and second photovoltaic panels.

Inverter system for photovoltaic power generation

Provided are a method of manufacturing a metal oxide and a substrate for a solar cell. The method of manufacturing the metal oxide according to the inventive concept includes mixing a metal precursor material, a basic material, amphiphilic molecules and distilled water to prepare a metal precursor solution, performing a first heat treatment with the metal precursor solution to form a metal oxide, and performing a second heat treatment with the metal oxide to form a pair of metal oxide disks having a single crystalline structure. A pair of zinc oxide disks includes a first disk, and a second disk separated from the first disk in a perpendicular direction to the first disk.

Method of manufacturing metal oxide crystal and method of fabricating substrate for solar cell

A method of fabricating a metal oxide sheet having a polycrystalline structure includes mixing a metal precursor material, a base material, and distilled water with each other to fabricate a preparation solution; adding an anionic surfactant into the preparation solution to forming a precursor solution; forming metal oxide nanoparticles in the precursor solution, wherein each of the metal oxide nanoparticles comprises a metal cation and an oxygen anion; and fabricating a metal oxide sheet by coupling the metal oxide nanoparticles to each other, wherein, in an aspect of a plane, the metal oxide sheet has a hexagonal shape and a polycrystalline structure.

Method of fabricating a metal oxide

Disclosed are a method of manufacturing a dye sensitized solar battery and a solar battery assembling apparatus. The method includes: forming electrode pads on electrodes of respective solar battery sub modules; applying a conductive adhesive on the electrode; and overlapping the electrodes of the solar battery sub modules, applying a current to the electrode pads, and then heating and hardening the conductive adhesive.

Method of manufacturing dye sensitized solar battery and solar battery assembling apparatus for the same

Provided is a solid type heat dissipation device for electronic communication appliances. The solid type heat dissipation device includes a graphite thin plate horizontally transferring heat, a plurality of metal fillers passing through the graphite thin plate to vertically transfer heat, and a plurality of metal thin plates attached to upper and lower surfaces of the graphite thin plate and connected to the metal fillers.

Solid type heat dissipation device

A sensing device may include an antenna. The antenna may include a top wafer and a bottom wafer coupled to the top wafer. The antenna may further include an air cavity between the top wafer and the bottom wafer. The sensing device may further include a substrate and an interposer disposed between the antenna and the substrate.

Sensing device having multi beam antenna array

Provided is an electronic device that includes an LTCC inductor including a first sheet disposed on a substrate and including a first conductive pattern, a second sheet disposed on the first sheet and including a second conductive pattern, and a via electrically connecting the first conductive pattern to the second conductive pattern, and a spacer disposed on a lower surface of the first sheet to provide an air gap between the substrate and the first sheet, wherein the first conductive pattern is exposed out of the lower surface of the first sheet.

Electronic device including LTCC inductor

A method and apparatus for controlling a wavelength tuning of an optical source in an optical communication system. An operating temperature of an optical source is controlled and monitored to shorten a wavelength tuning time of the optical source generated in an optical source generator. When the current operating temperature reaches a final target temperature, an operating current is supplied to the optical source generator, and transmission of the operating current to the optical source generator is controlled and monitored. When the operating current reaches a final operating current, the wavelength tuning of the optical source is terminated. The operating temperature is adjusted by distinguishing between a smaller amount of temperature change and a larger amount of temperature change to prevent oscillation at the point of reaching the final target temperature, thereby minimizing the time taken for the output wavelength tuning.

Method and apparatus for controlling wavelength tuning of optical source for optical communication

A channel allocation method of channels having different transmission speeds in a wavelength division multiplexing (WDM) system is provided. The channel allocation method in a multirate optical transmission system includes selecting a channel having the lowest transmission speed from not allotted channels, allotting the selected channel to the longest wavelength band of empty wavelength bands, and determining whether not allotted channels exist in order to repeatedly perform selecting the channel having the lowest transmission speed from the not allotted channels and allotting the selected channel to the longest wavelength band of the empty wavelength bands, until all the channels are allotted.

Channel allocation method in multirate WDM system

A dispersion compensating fiber (DCF), which is an amplification medium of an S-band discrete Raman amplifier (RA), has a trapezoid core, an inner cladding surrounding the trapezoid core; and an outer cladding surrounding the inner cladding. A ring is disposed between the inner cladding and the outer cladding. The refractive index plotted across the diameter of the trapezoid core as a function of distance is substantially trapezoidal in shape. The difference in refractive index between the trapezoid core and the outer cladding is 1.2 to 1.6%; between the inner cladding and the outer cladding is 0.4 to 0.8%; and between the ring and the outer cladding is 0.2 to 0.6%. The thickness of the ring is 0.8 to 1.2 times the radius of the trapezoid core, and the thickness of the inner cladding is 1 to 3 times the radius of the trapezoid core.

Dispersion compensating fiber for S-band discrete Raman amplifier

Provided are a polarization mode dispersion (PMD) compensator and method for automatically and rapidly compensating PMD occurring in an optical transmission fiber in a high-speed optical transmission system. The polarization mode dispersion compensator includes a separator and a differential time delay remover. The separator aligns orthogonal first and second polarization components of a received optical signal with respect to two orthogonal axes of a polarization beam splitter using optical signal information output via a second path of a first path and the second path of the two outputs of the polarization beam splitter, splits the first and second polarization components, and transmits the first polarization component via the first path and the second polarization component via the second path. The differential time delay remover receives the first and second polarization components that have been split to remove a differential time delay between the first and second polarization components.

PMD compensator based on separation of principal state of polarization control and differential group delay control, and method thereof

The present invention provides an apparatus and method for compensating for the variation of a gain spectrum attributable to the temperature variation of a fiber amplifier, and a long-wavelength band dispersion-compensating hybrid amplifier equipped with the gain spectrum compensating apparatus. The apparatus includes a DCF located between a first amplification stage and a second amplification stage to compensate for dispersion of an optical signal output from the first amplification stage and perform Raman amplification of the optical signal using input pumping light; at least one pumping light provision means for providing forward or backward pumping light to the DCF; first and second temperature detection means for detecting temperature variations of the first and second amplification stages, respectively; and control means for controlling intensity of the pumping light of the pumping light provision means according to the detected temperature variations.

Apparatus and method for gain-spectrum-tilt compensation in long-wavelength band dispersion-compensating hybrid fiber amplifier

Disclosed herein is an Erbium-Doped Fiber Amplifier (EDFA) used in a WDM (Wavelength Division Multiplexing) transmission system. In accordance with the present invention, a variation of the intensity of the output optical signal in the optical fiber amplifier, which results from an gain imbalance due to different wavelength distribution caused by the gain inhomogeneity characteristics, can be prevented by examining the laser diode sensitive to the gain inhomogeneity characteristics in the erbium-doped optical fiber amplifier, constructing the filter having spectrum characteristics capable of suppressing the gain imbalance of the optical signal outputted from the optical fiber amplifier, and driving the sensitive laser diode using the electrical signal obtained by branching some of the input optical signal and passing the branched optical signal through the filter and driving other laser diodes with a constant voltage value.

Erbium-doped optical fiber amplifier using input optical signal filtering

Disclosed herein is an inhomogeneity tunable erbium-doped optical fiber amplifier with a long wavelength band and method of blocking a backward amplified spontaneous light emission in the same. The optical fiber amplifier includes a control device situated between a first amplification stage and a second amplification stage for controlling an isolation rate of a backward amplified spontaneous light emission being propagated from a second amplification stage to the first amplification stage. The method blocks a backward amplified spontaneous light emission in a two-stage inhomogeneity tunable erbium-doped optical fiber amplifier with a long wavelength gain band, in which the backward amplified spontaneous light emission being propagated from a second amplification stage to a first amplification stage is blocked, and an isolation rate of the backward amplified spontaneous light emission is controlled according to the intensity of an optical signal inputted to the first amplification stage.

Inhomogeneity tunable erbium-doped fiber amplifier with long wavelength gain band and method of blocking propagation of backward amplified spontaneous light emission in the same

Growing community of inventors

Daejeon, South Korea

Moo Jung Chu