Abstract: In an OAM multiplexing communication system in which an M-UCA is provided in each of a transmitting station and a receiving station, signals in a plurality of OAM modes are generated and transmitted from each UCA of the transmitting station, signals in the plurality of OAM modes are received and demultiplexed by each UCA of the transmitting station, and streams of the number of UCAs×the number of OAM modes are subjected to spatial multiplex transmission, in which the transmitting station includes a signal processing unit generating the streams to be transmitted in the plurality of OAM modes from each of the UCAs of the M-UCA, and the receiving station includes a signal processing unit receiving the signals in the plurality of OAM modes demultiplexed by each of the UCAs of the M-UCA, and demultiplexes the received signals for each stream from signals in an identical OAM mode.

Abstract: An OAM multiplexing transmission device includes a unit generating each of the transmission streams in a baseband (BB), in which a channel estimation signal sequence is disposed before a transmission target data signal sequence, and a CP having a predetermined length is disposed in the first half of the channel estimation signal sequence, the channel estimation signal sequence is time-shifted with a channel estimation signal sequence (a basic channel estimation signal sequence) having a predetermined length and a zero correlation, by a predetermined shift value for each of the transmission streams; a unit converting a baseband signal sequence of the generated transmission streams to frequency conversion into RF band, or converting into IF band and then converting into the RF band; and a unit converting a plurality of the frequency-converted transmission streams into a plurality of OAM mode signals having different orders, and multiplexing spatially by using the UCA.

Abstract: In an OAM multiplexing communication system that subjects a plurality of signal sequences to multiplex transmission by using an OAM mode, a transmitting station includes a transmitting antenna using an M-UCA formed of a plurality of UCAs, and a unit performing basis transformation in each of the rotational direction dimension and a diameter direction dimension in a polar coordinate system having a center of UCAs as an origin, and subjecting the plurality of signal sequences to multiplex transmission for each complex mode formed by a combination of different bases in each dimension. A receiving station includes a receiving antenna using an M-UCA, and a unit receiving a signal subjected to multiplex transmission from the transmitting station, performing basis transformation in each of the rotational direction dimension and the diameter direction dimension by using the received signal, and demultiplexing the plurality of signal sequences subjected to the multiplex transmission.

Abstract: A transmitting station includes a plurality of transmitting weight multiplication units multiplying each of the transmission signal sequences by a transmitting weight, to be converted into MTX signals corresponding to UCAs forming an M-UCA so as to output the converted signals, and MTX transmitting OAM mode generation units inputting the signals corresponding to the UCAs and performing DFT on the input signals, so as to output to the corresponding UCA; and a receiving station includes MRX receiving OAM mode demultiplex units inputting signals from each of the UCAs forming the M-UCA and performing IDFT on the input signals, so as to output by each of received signal sequences, and a plurality of receiving weight multiplication units multiplying for each of them by a receiving weight, so as to demultiplex the spatially multiplexed received signal sequences and to output them in which interference between spatially multiplexed OAM modes is suppressed.

Abstract: A semiconductor package may include: a frame having a cavity and including a wiring structure connecting first and second surfaces of the frame to each other; a first connection structure d on the second surface of the frame and including a first redistribution layer connected to the wiring structure; a semiconductor chip on the first connection structure within the cavity and having connection pads connected to the first redistribution layer; an encapsulant encapsulating the semiconductor chip, covering the first surface of the frame, and having an upper surface substantially coplanar with an upper surface of the wiring structure; and a second connection structure including an insulating layer disposed on the upper surfaces of the encapsulant and the wiring structure, a second redistribution layer on the insulating layer, and vias penetrating through the insulating layer and connecting the wiring structure and the second redistribution layer.

Abstract: A fan-out semiconductor package includes a semiconductor chip, an encapsulant covering the semiconductor chip, a connection structure disposed below the semiconductor chip, and first and second metal pattern layers disposed on different levels on the semiconductor chip, wherein the first metal pattern layer is provided to electrically connect to an electrical connection member such as a frame, provided for electrical connection of the package in a vertical direction by a path via the second metal pattern layer.

Abstract: The invention provides a semiconductor package, which may include a connection structure including one or more redistribution layers. A semiconductor chip is disposed on the connection structure and has an active surface on which a connection pad electrically connected to the redistribution layer is disposed and an inactive surface opposite to the active surface. An encapsulant is disposed on the connection structure and covers at least a portion of the inactive surface of the semiconductor chip. A conductor pattern layer is embedded in the encapsulant such that one exposed surface of the conductor pattern layer is exposed from the encapsulant. A metal layer is disposed on the encapsulant and covers the one exposed surface of the conductor pattern layer.

Abstract: A semiconductor package includes a semiconductor chip including a connection pad disposed on an active surface of the semiconductor chip, a passivation layer disposed on the connection pad and the active surface and having an opening exposing at least a portion of the connection pad, and a capping pad covering the connection pad exposed to the opening; an encapsulant covering at least a portion of the semiconductor chip; and a connection structure disposed on the active surface of the semiconductor chip and including a connection via connected to the capping pad and a redistribution layer connected to the connection via, wherein the capping pad includes: a central portion disposed in the opening, and a peripheral portion extending from the central portion onto the passivation layer, and having a crystal grain having a size different from that of the crystal grain of the central portion.

Abstract: A semiconductor package includes a connection structure including a first insulating layer, a first redistribution layer disposed on the first insulating layer, and a first connection via penetrating through the first insulating layer and connected to the first redistribution layer, a semiconductor chip disposed on the connection structure, an encapsulant covering at least a portion of the semiconductor chip, a second insulating layer disposed on the encapsulant, a second redistribution layer including a signal line disposed on the encapsulant, and a heat dissipation layer disposed on the encapsulant and electrically insulated from the signal line.

Abstract: A receiver includes a local signal generator, a power phase adjuster, and a frequency converter so as to perform frequency conversion on signals included in a plurality of radio frequency bands. The local signal generator supplies a plurality of local signals. The power phase adjuster adjusts local signals in terms of signal power or relative phases. The frequency converter performs frequency conversion on radio frequency bands by use of local signals adjusted with the power phase adjuster, thus sorting them in a desired frequency range.

Abstract: A receiver includes a local signal generator, a power phase adjuster, and a frequency converter so as to perform frequency conversion on signals included in a plurality of radio frequency bands. The local signal generator supplies a plurality of local signals. The power phase adjuster adjusts local signals in terms of signal power or relative phases. The frequency converter performs frequency conversion on radio frequency bands by use of local signals adjusted with the power phase adjuster, thus sorting them in a desired frequency range.

Abstract: A fuel cell system and an operating method of the same. The fuel cell system includes a carbon monoxide adsorbing device that is disposed at an exit of a shift reactor and removes carbon monoxide which is not completely removed in the shift reactor. Therefore, a start-up time of the fuel cell system is remarkably reduced without poisoning catalysts of electrodes of the fuel cell. An overall volume of the fuel cell system can be reduced since the carbon monoxide adsorbing device is only operating during the start-up, and thus the fuel cell system can be economically manufactured and operated. Additionally, the carbon monoxide adsorbent can be regenerated, thereby increasing economic efficiency of the fuel cell system.

Abstract: A shift reactor for fuel cells, a fuel cell system employing the same, and an operating method of the same are provided. More particularly, a shift reactor for fuel cells is filled with a shift catalyst and includes an inlet through which reactants flow into the shift reactor and an outlet through which products flow out of the shift reactor. An oxygen supply duct and a valve capable of regulating the oxygen supply are positioned at the outlet side of the shift reactor. The oxygen supply allows for the temperature of the shift catalyst to be increased rapidly at startup, thereby significantly shortening the startup time of the shift reactor and thereby contributing to an improved practical operation of the fuel cell system.

Abstract: A hydrogen permselective membrane, a method of forming a permselective membrane and an apparatus comprising a permselective membrane, a porous substrate and an intermediate layer are described.

Abstract: In a startup method for fuel cell systems, and more particularly, a startup method which makes the fuel cell systems rapidly reach a steady state operation by significantly decreasing the time taken to increase the temperature of the shift reactor catalyst, gas discharged from a burner that heats a reformer is supplied into the shift reactor. In the startup method of the fuel cell system, the fuel cell systems rapidly reach a steady state operation thereby significantly improving the utility of the fuel cell system. In addition, the fuel cell system is economical in that gases discharged from burners included in the fuel cell system and waste heat are used.

Abstract: A shift reactor for fuel cells, a fuel cell system employing the same, and an operating method of the same are provided. More particularly, a shift reactor for fuel cells is filled with a shift catalyst and includes an inlet through which reactants flow into the shift reactor and an outlet through which products flow out of the shift reactor. An oxygen supply duct and a valve capable of regulating the oxygen supply are positioned at the outlet side of the shift reactor. The oxygen supply allows for the temperature of the shift catalyst to be increased rapidly at startup, thereby significantly shortening the startup time of the shift reactor and thereby contributing to an improved practical operation of the fuel cell system.

Abstract: A fuel cell system and an operating method of the same. The fuel cell system includes a carbon monoxide adsorbing device that is disposed at an exit of a shift reactor and removes carbon monoxide which is not completely removed in the shift reactor. Therefore, a start-up time of the fuel cell system is remarkably reduced without poisoning catalysts of electrodes of the fuel cell. An overall volume of the fuel cell system can be reduced since the carbon monoxide adsorbing device is only operating during the start-up, and thus the fuel cell system can be economically manufactured and operated. Additionally, the carbon monoxide adsorbent can be regenerated, thereby increasing economic efficiency of the fuel cell system.

Abstract: A hydrogen permselective membrane, a method of forming a permselective membrane and an apparatus comprising a permselective membrane, a porous substrate and an intermediate layer are described.

Abstract: A hydrogen permselective membrane, a method of forming a permselective membrane and an apparatus comprising a permselective membrane, a porous substrate and an optional intermediate layer are described. Using chemical vapor deposition (CVD) at low reactant gas concentration, high permselectivities are achieved with minimal reduction in hydrogen permeance.

Abstract: An optical attenuator includes a first multi-mode waveguide varying a phase of an optical signal input through an input terminal; first and second single-mode waveguides having an input terminal coupled to an output terminal of the first multi-mode waveguide and varying a phase of the optical signal by a thermo-optic effect by electrodes attached thereto; and a second multi-mode waveguide having an input terminal coupled to an output terminal of the first and second single-mode waveguides and varying a phase of the optical signal, wherein a predetermined optical power distribution obtained by offsetting or adding up a phase varied in the first and second multi-mode waveguides and a phase varied by the thermo-optic effect is transferred to an output terminal of the second multi-mode waveguide.