Abstract: According to a digital linearizing method, a digital input signal on a first path is operated with an output signal of a main amplifying unit, to thus detect distortion components included in the output signal of the main amplifying unit. A digital input signal on a second path is correlated with the detected distortion components, to thus adaptively control a gain of the digital input signal on the second path during the detection of the distortion components. Therefore, according to the above method, it is possible to effectively and correctly remove the distortion components included in the output signal of the main amplifying unit by amplifying the detected distortion components and coupling the amplified distortion components with the output signal of the main amplifying unit.

Abstract: A base station transmitter having a digital predistorter and predistortion method is disclosed. The predistortion is accomplished by delaying a digital input signal, predistorted by a predistortion unit, for a predetermined time. A coefficient of a non-linear characteristic model of a power amplifier is generated using a digital output signal, converted from an amplified output signal of the power amplifier, and the delayed digital input signal. A reference signal is randomly generated to produce a predistortion model having a characteristic opposite to the non-linear characteristic of the power amplifier. A predistortion error function is extracted by subtracting the reference signal and the non-linear characteristic model of the power amplifier, after the produced coefficient is applied to the model. A coefficient of the predistortion unit is controlled adaptively using the predistortion error function.

Abstract: A signal transmitting apparatus for an optical base station is disclosed. According to the invention, a base station outputs a digital IQ signal to an optical connecting unit. The optical connecting unit processes the digital IQ signal digitally, and transmits the digital signal over an optical network to a remotely located optical base station. The remote station digitally processes the signal before converting to an RF signal for transmission. The invention advantageously decreases signal loss and noise associated with analog processing in the optical connecting units and remote stations in the related art. System reliability is also improved.

Abstract: An improved method for mounting tape carrier package type integrated circuits on printed circuit boards. In the method, some of leads of the integrated circuit are preliminarily soldered with corresponding lead pattern on the printed circuit board after the integrated circuit is aligned on the printed circuit board so that the integrated circuit is prevented from being disordered while the printed circuit board including the integrated circuit aligned thereon is transferred to a soldering apparatus.

Abstract: A method for forming a contact plug formed of polysilicon and a method for manufacturing a semiconductor device using the same are provided. The contact plug is formed by etching back polysilicon which fills a contact hole and is deposited on an interlayer dielectric film using a gas mixture of SF6, CHF3, and CF4, thus planarizing the polysilicon. Also, the contact plug can be made protrude above the interlayer dielectric film by etching the entire surface of the exposed interlayer dielectric film around the polysilicon contact plug formed by etching back the polysilicon. According to the present invention, the degree of planarization of the polysilicon contact plug is improved by etching back the polysilicon using the gas mixture of SF6, CHF3, and CF4.

Abstract: A method for mounting an integrated circuit having a plurality of leads on a PCB. In order to mount the integrated circuit having a plurality of leads on the PCB, foreign substance on the PCB is first removed and a flux is simultaneously spread over the lead patterns formed on the PCB. After that, by aligning the leads of the integrated circuit with lead patterns on the PCB on which the flux is spread, some leads of the integrated circuit is temporarily fixed to the corresponding lead patterns of the PCB. After soldering the leads of the integrated circuit to the lead patterns of the PCB by radiating an optical beam on the entire whole surface, the soldered PCB is cooled, thereby mounting the integrated circuit on the PCB.

Abstract: Any one of at least two holding blocks loaded in a holding block storing portion is picked up and moved to cover an IC on a PCB of a PCB array. A light beam is applied to the whole surface of the PCB. The holding block is moved from the PCB to the holding block storing portion and cooled. It is then determined whether any other PCB to be soldered exists in the PCB array. If it is determined that any other PCB to be soldered exists in the PCB array, another holding block is picked up from the holding block storing portion and moved to cover an IC on the PCB of the PCB array. The above steps are repeated until all the PCBs of the PCB array to be soldered are completely soldered. If it is determined that any other PCB to be soldered does not exist in the PCB array, the PCB array is transferred to a subsequent process.

Abstract: A method of mounting an integrated circuit having a plurality of leads on a printed circuit board (PCB), by: removing foreign substances on the PCB; spreading a flux on lead patterns formed on the PCB; aligning the leads of the integrated circuit on the lead patterns on the PCB on which the flux is spread; soldering the leads and lead patterns by covering the part of a semiconductor chip of the aligned integrated circuit using a holding block and radiating an optical beam onto the whole surface thereof; and cooling the holding block and PCB which has been soldered, which prevents shorts and a poor contact generated by an earlier method. As the quality of soldering is enhanced and the lead is not pressured when soldering, the confidence of the integrated circuit after mounting is also enhanced. Moreover, by soldering all of the leads at one time, the operational time can be reduced.

Abstract: A rock fragmentation system using Gold Schmidt method and process for blasting using the machine are provided, wherein the blasting machine has a capacitor bank, a switch, a high voltage electric power supply, a first charge dump and a second charge dump, and an electrode assembly which is connected to capacitor bank and switch with a coxial cable and electrodes at a lower end of the electrode assembly, wherein an aluminum and metal oxide composition of a predetermined mixture ratio is inserted between electrodes in a lower end of the electrode assembly for generating an instant reaction energy by discharging the electric energy.