Abstract:
A phased array antenna system having low power amplifiers reduces power loss through several tens meters high frequency cables. The antenna system for transmitting a signal in a base station, comprising: a phased array unit for selecting an input signal through one of a plurality of beam ports, for dividing the input signal into a plurality of signals and for outputting the plurality of signals through a plurality of array ports, each of the signal having a linear phase difference according to difference of propagation path; a switch for receiving the input signal from a base station, for selecting one of the plurality of beam ports of said phased array and for transmitting the input signal to the selected beam port, responsive to a control signal transmitted from the base station; a plurality of low power amplifiers for low power amplifying the plurality of signals inputted from the plurality of array ports of said phased array; and phased array antennas for radiating the plurality of signals from said plurality of low power amplifiers, thereby providing a spatial power summation into a direction of equiphase plane allowing effective radiated power sufficiently enough to cover a cell into a steered direction selected by said switch.
Abstract:
Disclosed is a power supply module for a hall sensorless BLDC motor, including: a high-voltage/large-current power device t applied with high voltage/large current and including a plurality of power devices driving the hall sensorless brushless direct current (BLDC) motor; a motor driving circuit sensing and controlling a positional signal or a velocity signal of the hall sensorless BLDC motor and generating a PWM control signal for controlling the hall sensorless BLDC motor; and a power device driving circuit driving the high-voltage/large-current power device according to the PWM control signal of the motor driving circuit, wherein the high-voltage/large-current power device, the power device driving circuit, and the motor driving circuit are CMOS-integrated on the same substrate.
Abstract:
Provided is an electro-optic modulating device. The electro-optic modulating device includes an optical waveguide with a vertical structure and sidewalls of the vertical structure are used to configure a junction.
Abstract:
Disclosed is a power supply module for a hall sensorless BLDC motor, including: a high-voltage/large-current power device t applied with high voltage/large current and including a plurality of power devices driving the hall sensorless brushless direct current (BLDC) motor; a motor driving circuit sensing and controlling a positional signal or a velocity signal of the hall sensorless BLDC motor and generating a PWM control signal for controlling the hall sensorless BLDC motor; and a power device driving circuit driving the high-voltage/large-current power device according to the PWM control signal of the motor driving circuit, wherein the high-voltage/large-current power device, the power device driving circuit, and the motor driving circuit are CMOS-integrated on the same substrate.
Abstract:
The present invention relates to an orthodontic wire and a manufacturing method thereof, and more particularly, to an orthodontic wire, which is not harmful to the human body and is capable of continuously holding the color of teeth, and a manufacturing method of the orthodontic wire. According to the present invention, there is provided an orthodontic wire, comprising a metal wire formed of a shape memory alloy material; a silver (Ag) film applied to a surface of the metal wire; and a polymer compound film applied to a surface of the silver (Ag) film to prevent the silver (Ag) film from being discolored.
Abstract:
Provided is a method of fabricating a T-type gate including the steps of: forming a first photoresist layer, a blocking layer and a second photoresist layer to a predetermined thickness on a substrate, respectively; forming a body pattern of a T-type gate on the second photoresist layer and the blocking layer; exposing a predetermined portion of the second photoresist layer to form a head pattern of the T-type gate, and performing a heat treatment process to generate cross linking at a predetermined region of the second photoresist layer except for the head pattern of the T-type gate; performing an exposure process on an entire surface of the resultant structure, and then removing the exposed portion; and forming a metal layer of a predetermined thickness on an entire surface of the resultant structure, and then removing the first photoresist layer, the blocking layer, the predetermined region of the second photoresist layer in which the cross linking are generated, and the metal layer, whereby it is possible to readily perform a compound semiconductor device manufacturing process, and to reduce manufacturing cost by means of the increase of manufacturing yield and the simplification of manufacturing processes.
Abstract:
A method for fabricating a power semiconductor device having a trench gate structure is provided. An epitaxial layer of a first conductivity type having a low concentration and a body region of a second conductivity type are sequentially formed on a semiconductor substrate of the first conductivity type having a high concentration. An oxide layer pattern is formed on the body region. A first trench is formed using the oxide layer pattern as an etching mask to perforate a predetermined portion of the body region having a first thickness. A body contact region of the second conductivity type having a high concentration is formed to surround the first trench by impurity ion implantation using the oxide layer pattern as an ion implantation mask. First spacer layers are formed to cover the sidewalls of the first trench and the sidewalls of the oxide layer pattern. A second trench is formed using the oxide layer pattern and the first spacer layers as etching masks to perforate a predetermined portion of the body region having a second thickness greater than the first thickness. A source region of the first conductivity type having a high concentration is formed to surround the second trench by impurity ion implantation using the oxide layer pattern and the first spacer layers as ion implantation masks. Second spacer layers are formed to cover the sidewalls of the second trench and the sidewalls of the first spacer layers. A third trench is formed to a predetermined depth of the epitaxial layer using the oxide layer pattern, the first spacer layers, and the second spacer layers as etching masks. A gate insulating layer is formed in the third trench. A gate conductive pattern is formed in the gate insulating layer. An oxide layer is formed on the gate conductive layer pattern. The first and second spacer layers are removed. A first metal electrode layer is formed to be electrically connected to the source region and the body contact region. A second metal electrode layer is formed to be electrically connected to the gate conductive layer pattern. A third metal electrode layer is formed to be electrically connected to the semiconductor substrate.
Abstract:
A method of fabricating a vertical TDMOS power device using sidewall spacers and a self-align technique and a TDMOS power device of the same. The TDMOS is fabricated using only 3 masks and a source is formed using the self-align technique to embody a highly integrated trench formation. During the process, ion implantation of high concentration into the bottom of the trench makes a thick oxide film grow on the bottom and the corner of the gate, so that electrical characteristic, specifically leakage current and breakdown voltage of the device can be improved. Also, process steps can be much decreased to lower process cost, high integration is possible, and reliability of the device can be improved.
Abstract:
Provided are a semiconductor device and a method of fabricating the same. The method includes: forming a trench in a semiconductor substrate of a first conductive type; forming a trench dopant containing layer including a dopant of a second conductive type on a sidewall and a bottom surface of the trench; forming a doping region by diffusing the dopant in the trench dopant containing layer into the semiconductor substrate; and removing the trench dopant containing layer.