Abstract: A wireless communication system provides an antenna apparatus for the wireless communication system. The antenna apparatus includes a base, a plurality of Yagi-Uda antenna modules disposed in a specific arrangement, a plurality of floating metal modules correspondingly installed in upper portions of the Yagi-Uda antenna modules and selectively connected to a corresponding Yagi-Uda module among the plurality of Yagi-Uda antenna modules, a switching element for selectively switching the floating metal module and the Yagi-Uda antenna module, and a controller for controlling the Yagi-Uda antenna module to comprise a directivity in a desired direction by selectively switching the switching element.

Abstract: Substrate embedded horn antenna includes a dielectric, metal patterns, metal vias and a ground plate. The metal patterns are embedded by being stacked in dielectric. Metal patterns are hollow rectangle types or hollow circle types. Metal vias connect layers of metal patterns by being embedded between layers of metal patterns. Ground plate is formed in an upper side of dielectric. Metal patterns form waveguide structure by being stacked in radial shape. Waveguide structure propagates electromagnetic wave by focusing electromagnetic wave. Embedded horn antenna capable of selectively using vertical radiation and horizontal radiation may be implemented using the via and metal pattern in dielectric substrate. Embedded horn antenna may be implemented in small size with high gain. Vertical embedded horn antenna and horizontal embedded horn antenna may be implemented in a substrate. Method of manufacturing embedded horn antenna capable of selectively using vertical radiation and horizontal radiation may be provided.

Abstract: Disclosed is a millimeter wave antenna for diagonal radiation. A first metal layer and a second metal layer having a form of microstrip wire are coated on the bottom surface and at least a partial region of the top surface of a dielectric substrate, respectively. When viewed in a direction perpendicular to the top surface of the dielectric substrate, the second metal layer is covered by the first metal layer. The microstrip wire of the second metal layer may have a length of more than half of a wavelength of a RF signal. The long-wire antenna has a radiation pattern in upward diagonal direction when a signal to transmit is fed under a condition that the first metal layer is grounded. The form of the second metal layer may be a straight line, Y-shape, ?-shape, or etc. An impedance matching metal layer may be added to the second metal layer.

Abstract: The present invention relates to novel cephalosporin derivatives represented by X, Y, L, R1, and R2 are as same as defined in the description of the invention. The present invention also relates to pharmaceutical antibiotic compositions comprising a novel celphalosporin derivative represented by Chemical Formula 1, a prodrug thereof, a hydrate thereof, a solvate thereof, an isomer thereof, or a pharmaceutically acceptable salt thereof as an effective ingredient. According to the present invention, novel cephalosporin derivatives, a prodrug thereof, a hydrate thereof, a solvate thereof, an isomer thereof, or a pharmaceutically acceptable salt thereof as an effective ingredient for the broad spectrum of antibiotic resistant, low toxicity, particularly in Gram-negative bacteria, which can be useful with strong antimicrobial activity.

Abstract: Provided herein is a method and apparatus for implementing a multi-screen by distributing numerous screens and sharing an input interface between user apparatuses, the method including: setting up, by a first user apparatus, a network with each of at least one second user apparatus; receiving, by the first user apparatus, information for setting up each of the at least one second user apparatus as the multi-screen through the network; and setting up, by the first user apparatus, each of the at least one second user apparatus as the multi-screen.

Abstract: An antenna device in a wireless communication includes antenna wires of four sides which include three feeding points and have a loop structure and four main switches which are located among the antenna wires of the four sides, wherein the antenna device operates as a loop antenna when the antenna wires of the four sides are connected according to operations of the main switches and wherein the antenna device operates as dipole antennas when the antenna wires of the four sides are disconnected according to operations of the main switches.

Abstract: An OOK modulation device according to the present inventive concept includes: an oscillator outputting a first frequency signal in which the frequency varies according to an input voltage; a frequency multiplier switching unit operating according to an OOK input data and switching on/off a second frequency signal that is obtained by multiplying the first frequency signal; and a switching amplifying unit amplifying and switching the second frequency signal according to the OOK input data to output an OOK modulation signal.

Abstract: An OOK modulation device according to the present inventive concept includes: an oscillator outputting a first frequency signal in which the frequency varies according to an input voltage; a frequency multiplier switching unit operating according to an OOK input data and switching on/off a second frequency signal that is obtained by multiplying the first frequency signal; and a switching amplifying unit amplifying and switching the second frequency signal according to the OOK input data to output an OOK modulation signal.

Abstract: An envelope tracking power transmitter includes an envelope amplifier, a common-gate power modulation linearizer and a power amplifier. The envelope amplifier may receive a first envelope voltage to generate a power supply voltage that is amplified in proportion to change of the first envelope voltage. The common-gate power modulation linearizer may receive a second envelope voltage to amplify the second envelope voltage according to change of the second envelop voltage. The power amplifier may receive a first output of the envelope amplifier as a power supply voltage and a drain bias voltage, may receive a second output of the common-gate power modulation linearizer as a common gate bias voltage, and may amplify a radio frequency (RF) input signal to provide a RF output signal by maintaining an output capacitance according to an envelope of the RF input signal.

Abstract: Substrate embedded horn antenna includes a dielectric, metal patterns, metal vias and a ground plate. The metal patterns are embedded by being stacked in dielectric. Metal patterns are hollow rectangle types or hollow circle types. Metal vias connect layers of metal patterns by being embedded between layers of metal patterns. Ground plate is formed in an upper side of dielectric. Metal patterns form waveguide structure by being stacked in radial shape. Waveguide structure propagates electromagnetic wave by focusing electromagnetic wave. Embedded horn antenna capable of selectively using vertical radiation and horizontal radiation may be implemented using the via and metal pattern in dielectric substrate. Embedded horn antenna may be implemented in small size with high gain. Vertical embedded horn antenna and horizontal embedded horn antenna may be implemented in a substrate. Method of manufacturing embedded horn antenna capable of selectively using vertical radiation and horizontal radiation may be provided.

Abstract: A wireless communication system provides an antenna apparatus for the wireless communication system. The antenna apparatus includes a base, a plurality of Yagi-Uda antenna modules disposed in a specific arrangement, a plurality of floating metal modules correspondingly installed in upper portions of the Yagi-Uda antenna modules and selectively connected to a corresponding Yagi-Uda module among the plurality of Yagi-Uda antenna modules, a switching element for selectively switching the floating metal module and the Yagi-Uda antenna module, and a controller for controlling the Yagi-Uda antenna module to comprise a directivity in a desired direction by selectively switching the switching element.

Abstract: Disclosed are a beamformer and a beamforming method. The beamformer includes a plurality of dividers, each of which divides an input signal along a plurality of paths, an input switch which selects one of the dividers such that the input signal is input to the selected divider, a phase shifter which shifts phases of respective output signals from the divider, and an output switch which transmits the output signals from the phase shifter to an antenna.

Abstract: An antenna device in a wireless communication includes antenna wires of four sides which include three feeding points and have a loop structure and four main switches which are located among the antenna wires of the four sides, wherein the antenna device operates as a loop antenna when the antenna wires of the four sides are connected according to operations of the main switches and wherein the antenna device operates as dipole antennas when the antenna wires of the four sides are disconnected according to operations of the main switches.

Abstract: The present invention relates to novel cephalosporin derivatives represented by Chemical Formula 1. Wherein, X, Y, L, R1, and R2 are as same as defined in the description of the invention. The present invention also relates to pharmaceutical antibiotic compositions comprising a novel celphalosporin derivative represented by Chemical Formula 1, a prodrug thereof, a hydrate thereof, a solvate thereof, an isomer thereof, or a pharmaceutically acceptable salt thereof as an effective ingredient. Compounds of the present invention are effective ingredients for the broad spectrum of antibiotic resistance, exhibit low toxicity, particularly in Gram-negative bacteria, which can be useful with strong antimicrobial activity.

Abstract: The present invention relates to novel cephalosporin derivatives represented by Chemical Formula 1. Wherein, X, Y, L, R1, and R2 are as same as defined in the description of the invention. The present invention also relates to pharmaceutical antibiotic compositions comprising a novel celphalosporin derivative represented by Chemical Formula 1, a prodrug thereof, a hydrate thereof, a solvate thereof, an isomer thereof, or a pharmaceutically acceptable salt thereof as an effective ingredient. According to the present invention, novel cephalosporin derivatives, a prodrug thereof, a hydrate thereof, a solvate thereof, an isomer thereof, or a pharmaceutically acceptable salt thereof as an effective ingredient for the broad spectrum of antibiotic resistant, low toxicity, particularly in Gram-negative bacteria, which can be useful with strong antimicrobial activity.

Abstract: A resistive frequency mixing apparatus includes a first frequency mixer having a source follower FET, and a second frequency mixer having a common source FET. The resistive frequency mixing apparatus perform a frequency mixing of an RF depending on an LO signal to generate a down-converted IF signal when the RF signal is applied to the source follower FET and the LO signal is applied to the common source FET. Further, the resistive frequency mixing apparatus performs a frequency mixing of an IF signal depending on an LO signal through the use of the source follower FET to produce an up-converted RF signal when the IF signal is applied to the common source FET and the LO signal is applied to the common source FET.

Abstract: A wireless communication module includes a plurality of monolithic millimeter-wave integrated circuits (MMICs) for signal processing attached to the top surface of a multi-layer low temperature co-fired ceramic substrate; a planar transmission line formed on the top surface of the multi-layer substrate for communications between the MMICs; a metal base attached to the bottom surface of the multi-layer substrate and having an opening to which an antenna is attached; a plurality of vias for connecting the metal base and the planar transmission line within the multi-layer substrate to establish a uniform potential on a ground plane of the multi-layer substrate; an embedded waveguide formed in the opening surrounded with the vias within the multi-layer substrate; and a planar transmission line-to-waveguide transition apparatus for the transition of waves between the planar transmission line and the embedded waveguide.

Abstract: Provided is a sub-harmonic frequency mixer having a structure in which two terminals of transistors receiving a Radio Frequency (RF) signal and a Local Oscillation (LO) signal are coupled. The frequency mixer is composed of a single-level structure of transistors and thus can be driven at a lower supply voltage compared to a common frequency mixer. A direct-conversion receiver employing such a frequency mixer needs an RF signal and an LO signal sources of single-phase. Therefore, the direct-conversion receiver has an architecture that simplifies a whole RF transceiver circuit and thus can be advantageously applied in implementing SoC (System-on-Chip) for a low power, high integration, low price and subminiature wireless transceiver circuit.

Abstract: A phase shifter includes a substrate; a signal line formed on a specific region in an upper surface of the substrate; and an air gap which is formed within the substrate and changes effective permittivity of the substrate to delay phase of a signal supplied to the signal line. The phase shifter delays a phase of a signal by controlling effective permittivity using an air gap, thereby having outstandingly low insertion loss as compared to existing phase shifters. Further, the phase shifter can be manufactured in a same length as a reference line so that the phase shifter can be in a compact size.

Abstract: There is provided a power amplifying device having a linearizer in which a bias circuit has an initial impedance set when initially operated, then the impedance is varied according to a level of an input signal and the input signal is amplified in a broad range from a low level region to a high level region, thereby improving linearity of an output signal. The power amplifying device including: an amplifying unit receiving a bias power source and amplifying an input signal; a bias unit varying the bias power source according to a set impedance to provide to the amplifying unit; and an impedance setting unit setting the impedance of the bias unit in response to a preset control voltage when the bias unit is initially operated and re-setting the impedance of the bias unit according to a level of the input signal of the amplifying unit after initial operation of the bias unit.