Abstract: Provided is a switching circuit for a millimeter waveband control circuit. The switching circuit for a millimeter waveband control circuit includes a switching cell disposed on a signal port path to match an interested frequency and including at least one transistor coupled vertically to an input/output transmission line and a plurality of ground via holes disposed symmetrically in an upper portion and a lower portion of the input/output transmission line; capacitors for stabilizing a bias of the switching cell; and bias pads coupled in parallel to the capacitor to control the switching cell.

Abstract: Provided are a transistor of a semiconductor device and method of fabricating the same. The transistor includes: an epitaxy substrate disposed on a semi-insulating substrate and having a buffer layer, a first Si planar doping layer, a first conductive layer, a second Si planar doping layer, and a second conductive layer, which are sequentially stacked, the second Si planar doping layer having a doping concentration different from that of the first Si planar doping layer; a source electrode and a drain electrode diffusing into the first Si planar doping layer to a predetermined depth and disposed on both sides of the second conductive layer to form an ohmic contact; and a gate electrode disposed on the second conductive layer between the source and drain electrodes and being in contact with the second conductive layer. In this structure, both isolation and switching speed of the transistor can be increased.

Abstract: A field effect transistor having a T- or ?-shaped fine gate electrode of which a head portion is wider than a foot portion, and a method for manufacturing the field effect transistor, are provided. A void is formed between the head portion of the gate electrode and a semiconductor substrate using an insulating layer having a multi-layer structure with different etch rates. Since parasitic capacitance between the gate electrode and the semiconductor substrate is reduced by the void, the head portion of the gate electrode can be made large so that gate resistance can be reduced. In addition, since the height of the gate electrode can be adjusted by adjusting the thickness of the insulating layer, device performance as well as process uniformity and repeatability can be improved.

Abstract: Provided is a power device having a connection structure compensating for a reactance component, in which transistors are arranged and connected to minimize deterioration of transistor properties caused by heat by compensating for a reactance component causing a phase difference due to transmission lines used for connecting a plurality of transistors in parallel such that the power device to be used for a high-frequency power amplifier outputs high power, and transmitting heat generated by high output power to a heat sink to be dissipated.

Abstract: Provided is a method of fabricating a pseudomorphic high electron mobility transistor (PHEMT).

Abstract: A field effect transistor having a T- or ?-shaped fine gate electrode of which a head portion is wider than a foot portion, and a method for manufacturing the field effect transistor, are provided. A void is formed between the head portion of the gate electrode and a semiconductor substrate using an insulating layer having a multi-layer structure with different etch rates. Since parasitic capacitance between the gate electrode and the semiconductor substrate is reduced by the void, the head portion of the gate electrode can be made large so that gate resistance can be reduced. In addition, since the height of the gate electrode can be adjusted by adjusting the thickness of the insulating layer, device performance as well as process uniformity and repeatability can be improved.

Abstract: Provided is a high-isolation switching device for a millimeter-wave band control circuit. By optimizing a cell structure to improve the isolation of an off-state without deteriorating the insertion loss of an on-state, it is possible to implement a high-isolation switching device useful in the design and manufacture of a millimeter-wave band control circuit such as a phase shifter or digital attenuator using switching characteristics. In addition, when a switch microwave monolithic integrated circuit (MMIC) is designed to use the switching device, it is not necessary to use a multi-stage shunt field effect transistor (FET) to improve isolation, nor to dispose an additional ?/4 transformer transmission line, inductor or capacitor near the switching device. Thus, chip size can be reduced, degree of integration can be enhanced, and manufacturing yield can be increased. Consequently, it is possible to reduce manufacturing cost.

Abstract: A method of forming a fine T- or gamma-shaped gate electrode is provided, which is performed by a lithography process using a multi-layered photoresist layer having various sensitivities, deposition of an insulating layer, and an etching process.

Abstract: Provided is a method of fabricating a pseudomorphic high electron mobility transistor (PHEMT).

Abstract: Provided is a method of manufacturing a field effect transistor (FET).

Abstract: Provided is a system and method for broadcasting stereoscopic video data to users on the Internet based on Moving Picture Experts Group (MPEG)-4. The system includes: an encoding server for receiving stereoscopic video data, audio data, and Object Descriptor/Binary Format for Scene (OD/BIFS), which is information for controlling a content, and encoding the data into elementary stream (ES) having an MPEG-4 structure; a web server for receiving from the client any one among two-dimensional video display mode, field-shuttering video display mode and frame-shuttering video display mode; and a streaming server for generating a RTP (RTP) packet for real-time data transmission on the Internet by multiplexing the ES based on the display mode inputted into the web server, and transmitting the RTP packet to the client.

Abstract: A pseudomorphic high electron mobility transistor (PHEMT) power device formed on a double planar doped epitaxial substrate and capable of operating with a single voltage source and a method for manufacturing the PHEMT power device are provided. The PHEMT power device includes: an epitaxial substrate including a GaAs buffer layer, an AlGaAs/GaAs superlattice layer, an updoped AlGaAs layer, a first doped silicon layer, a first spacer, an InGaAs electron transit layer, a second spacer, a second doped silicon layer having a different doping concentration from the first doped silicon layer, a lightly doped AlGaAs layer, and an undoped GaAs cap layer stacked sequentially on a semi-insulating GaAs substrate; a source electrode and a drain electrode formed on and in ohmic contact with the undoped GaAs cap layer; and a gate electrode formed on the lightly doped AlGaAs layer to extend through the undoped GaAs cap layer.

Abstract: A pseudomorphic high electron mobility transistor (PHEMT) power device formed on a double planar doped epitaxial substrate and capable of operating with a single voltage source and a method for manufacturing the PHEMT power device are provided. The PHEMT power device includes: an epitaxial substrate including a GaAs buffer layer, an AlGaAs/GaAs superlattice layer, an updoped AlGaAs layer, a first doped silicon layer, a first spacer, an InGaAs electron transit layer, a second spacer, a second doped silicon layer having a different doping concentration from the first doped silicon layer, a lightly doped AlGaAs layer, and an undoped GaAs cap layer stacked sequentially on a semi-insulating GaAs substrate, a source electrode and a drain electrode formed on and in ohmic contact with the undoped GaAs cap layer; and a gate electrode formed on the lightly doped AlGaAs layer to extend through the undoped GaAs cap layer.

Abstract: Disclosed are a Scutellariae Radix extract and a pharmaceutical preparation comprising the extract as a pharmaceutically effective ingredient. With significant neuroprotective activity, but no toxicity, the Scutellariae Radix extract is suitable for use in the prophylaxis and treatment of brain diseases, such as apoplexy, Parkinson's disease and senile dementia.

Abstract: A system for synchronizing a carrier frequency of an orthogonal frequency division multiplexing (OFDM) transmission apparatus, even when a carrier frequency offset is above a frequency bandwidth of one subchannel. The synchronization of the carrier frequency in the OFDM transmission apparatus is accomplished by alternating between a coarse mode for synchronizing an integer part of the carrier frequency offset and a fine mode for synchronizing a prime part of the carrier frequency offset.

Abstract: A pad conditioner for a chemical mechanical polishing (CMP) apparatus which is adapted to remove a glazing phenomenon occurring on a polishing pad when wafers are machined using the CMP apparatus. The pad conditioner includes a swing arm pivotally mounted at one end thereof to a desired portion of the upper surface of the chemical mechanical polishing apparatus by a pivot shaft, a rotating oscillator coupled to the other end of the swing arm and adapted to horizontally rotate a conditioning tool mounted thereto while vertically oscillating the conditioning tool, the rotating oscillator including a rotating unit for horizontally rotating the conditioning tool and an oscillation generating unit for vertically oscillating the conditioning tool, and a vertical carrier unit coupled to the other end of the swing arm and adapted to vertically move the rotating oscillator.