摘要:
An antenna and a communication system with the antenna are provided. The antenna may include a first layer including a plurality of folded stubs, a second layer including a pattern of the folded stubs, and a third layer connected to ground is disposed between the first layer and the second layer.
摘要:
A method for determining a transmission power in a multi-input multi-output (MIMO) system based on a cooperative transmission is provided. The method includes setting a power constraint condition of a transmitter and target quality information of a receiver. The method further includes determining the transmission power to be allocated to the transmitter to transmit the data to the receiver based on the power constraint condition and the target quality information.
摘要:
Provided is a method and device for increasing energy efficiency by adaptively performing clipping with respect to an input signal. The method may adaptively determine a clipping ratio (CR) based on a modulation method of the communication device and perform clipping based on the determined CR.
摘要:
A refrigerator comprising a main body which is formed with three or more storage compartments and a cooling unit having a plurality of evaporators corresponding to the respective storage compartments, the cooling unit comprising a refrigerant supply pipe to supply a refrigerant to the plurality of evaporators; a plurality of refrigerant branch pipes which are branched from the refrigerant supply pipe to mount the evaporators thereto, and to at least one of which the plurality of evaporators are connected in series; and a refrigerant connection pipe to connect an outlet of one of the plurality of refrigerant branch pipes and an inlet of the other one of the plurality of refrigerant branch pipes.
摘要:
A management system and method of a reticle in an exposing process are disclosed. A calculator calculates an accumulated dosage of an illuminating light irradiated onto a reticle used in a photolithography process. The calculator is connected to an exposing apparatus to expose photoresist on a semiconductor substrate. A comparator compares the calculated accumulated dosage with a preset reference dosage. When the calculated accumulated dosage is greater than or equal to the reference dosage, a controller suspends the photolithography process. Minimizing haze contamination on the reticle, thus preventing process failures.
摘要:
An air shower head of an exposure device of photolithography equipment is free of chemical substances that could otherwise contaminate a photoresist layer on a semiconductor wafer and degrade the profile of the photoresist pattern. The air shower head is interposed between a lens system of the exposure device and a wafer stage, and has a hole in the middle thereof through which exposure light can pass to a wafer supported on the stage. The air shower head includes an upper frame defining a cavity open at the bottom thereof, and a porous bottom member covering the bottom of the upper frame. The porous member is mechanically secured to bottom ends of both the inner and outer side walls of the upper frame, i.e., without the use of chemical binders, to reduce the ability of the air shower head to serve as a source of contamination.
摘要:
A chemical mechanical polishing (CMP) apparatus for planarizing the surface of a semiconductor wafer is provided with a washing unit including first, second and third nozzles installed within a load-cup where the loading and unloading of the wafers takes place. The first nozzles spray deionized water toward the top face of a pedestal on which the wafers are placed in the load cup, thereby washing contaminants off of the pedestal. The second nozzles spray deionized water toward a membrane provided at the bottom of a polishing head, thereby washing the membrane. The third nozzles spray deionized water through purge holes formed in a retainer ring of the polishing head toward a space formed between the outer surface of the membrane and the inner surface of the retainer ring. Consequently, contaminants induced into the space are washed away. The CMP apparatus also includes an exhaust unit having an outlet, an exhaust pump and an exhaust pipe connecting the outlet and the exhaust pump, for exhausting contaminants to the outside of the CMP apparatus through a protective cover thereof. The exhaust outlet is provided at the bottom of a side of the protective cover.
摘要:
A refrigerator, with an inner casing forming a drawer type storage compartment and a drawer unit being received in and combined with the drawer type storage compartment, the refrigerator having: at least a pair of rail units provided between the inner casing and the drawer unit enabling the drawer unit to slide against the inner casing; a support part positioned at the inner casing, supporting the rail unit, and preventing the rail unit from moving upward and downward; and a combining part combining the rail unit with the support part, the combining part enabling the support part to move relative to the rail unit in a direction approximately perpendicular to a surface of the inner casing.
摘要:
Provided is a method and device for increasing energy efficiency by adaptively performing clipping with respect to an input signal. The method may adaptively determine a clipping ratio (CR) based on a modulation method of the communication device and perform clipping based on the determined CR.
摘要:
A central control apparatus and method thereof include a traffic demand receiving unit, a traffic demand calculating unit, a base station efficiency calculating unit, and a base station management unit. The traffic demand receiving unit is configured to receive a required traffic demand and a current location of each of terminals. The traffic demand calculating unit is configured to calculate traffic of each of base stations to which a terminal is unassigned. The base station efficiency calculating unit is configured to calculate an energy efficiency of each of the base stations. The base station management unit configured to verify a base station with an optimum energy efficiency, to activate the base station with the optimum energy efficiency, and to assign the terminals of a corresponding region to the base station with the optimum energy efficiency.