Electronics and Telecommunications Research Institute

Information and Communications University Educational Foundation

Youn Sub Noh

Chul Soon Park

Hae Cheon Kim

Ho Kyun Ahn

Sang Heung Lee

Jong Won Lim

In Bok Yom

Seong Il Kim

Hyun Wook Jung

Sung Jae Chang

Ji Hoon Kim

Man Seok Uhm

Joon Hyung Kim

Il Gyu Choi

Soo Cheol Kang

Hong Yeol Lee

Changsoo Kwak

Chang Soo Kwak

So Hyeun Yun

An apparatus and method for generating an electrical circuit of semiconductor channel resistor including a first passive element part including a resistor and a capacitor connected in parallel between a first port and a second port, and an ohmic resistor connected in series to the resistor and the capacitor which are connected in parallel are provided. The apparatus includes a substrate selection part configured to receive a selected substrate item; a resistor selection part configured to receive a selected resistor item; a capacitor selection part configured to receive a selected capacitor item; and a circuit generating part configured to generate an electrical circuit from the selected substrate item, the selected resistor item, and the selected capacitor item.

Electrical circuit of semiconductor channel resistor and apparatus and method for generating the same

A method of manufacturing a high-electron-mobility transistor device is provided. The method includes sequentially forming a transition layer and a semiconductor layer on a substrate, etching a portion of a surface of the semiconductor layer to form a barrier layer region having a certain depth and forming a barrier layer in the barrier layer region, forming a source electrode and a drain electrode on a 2-dimensional electron gas (2-DEG) layer upward exposed at a surface of the semiconductor layer, in defining the 2-DEG layer formed along an interface between the semiconductor layer and the barrier layer, forming a passivation layer on the semiconductor layer, the barrier layer, the source electrode, and the drain electrode and etching a portion of the passivation layer to upward expose the source electrode, the drain electrode, and the barrier layer, and forming a gate electrode on the upward exposed barrier layer.

High-electron-mobility transistor device and method of manufacturing the same

The present invention improves a heat dissipation property of a semiconductor device by transferring hexagonal boron nitride (hBN) with a two-dimensional nanostructure to the semiconductor device. A semiconductor device of the present invention includes a substrate having a first surface and a second surface, a semiconductor layer formed on the first surface of the substrate, an hBN layer formed on at least one surface of the first surface and the second surface of the substrate, and a heat sink positioned on the second surface of the substrate. A radiation rate of heat generated during driving of an element is increased to decrease a reduction in lifetime of a semiconductor device due to a temperature increase. The semiconductor device has a structure and configuration which are very effective in improving a rapid temperature increase due to heat generated by high-power semiconductor devices.

Semiconductor device with high heat dissipation property using hexagonal boron nitride and method of manufacturing the same

A tunable filter device that changes a central frequency and a bandwidth is provided. The tunable filter device may include a body forming a cavity together with a cover, a resonator attached to or integrally formed on a lower surface of the cavity, a frequency-tuning element including a head and a shaft, the shaft passed through the cover and inserted in the resonator, and a cam disposed on the head to contact the head, wherein an insertion length of the shaft is controlled by the cam.

Variable high frequency filter device and assembly

Provided is a line filter. The line filter includes a plurality of dielectric layers stacked one another, a plurality of line resonator each comprising transmission lines on at least two of the dielectric layers, and a tuning unit adjusting a binding amount and resonance frequency of the line resonators. Since the line filter includes at least one line resonator on at least two stacked dielectric layers, the integration can be easily realized. Further, since the line filter can be adjusted even after the line filter is manufacture, the line filter has an excellent frequency property. Since the line filter is realized on the plurality of the dielectric layers, the frequency band can be widened.

Line filter formed on dielectric layers

Provided is an SPDT switch having improved isolation characteristics in an RF band. The SPDT switch includes a serial switching unit, a current sink unit, a switching isolation unit, and a DC blocking unit. The serial switching unit includes first and second HBTs. The current sink unit sinks a current flowing from a common input terminal to each of first and second output terminals of the serial switching unit. The switching isolation unit causes an unselected output terminal of the first and second output terminals to be electrically isolated from the common input terminal when the serial switching unit operates. The DC blocking unit blocks a DC between the first HBT and the first output terminal and a DC between the second HBT and the second output terminal. Accordingly, it is possible to provide better insertion-loss and isolation characteristics in higher frequency bands than typical switches.

SPDT switch for radio frequency switching and method for enhancing isolation thereof

A power amplifier for use in a mobile handset includes an amplifying transistor, a bias circuit including a bias transistor, the bias circuit providing a bias current to bias the amplifying transistor, and a bias current control circuit, responsive to fluctuation in a reference voltage and variation in temperature, for adjusting the bias current to control an operation current of the amplifying transistor.

Bias circuit for providing a constant bias current to a power amplifier

An adaptive bias circuit is provided for an amplifier module including a RF power amplifier for amplifying an input signal to generate an output signal, wherein the bias circuit receives the input signal to adjust a driving current to control a quiescent current of the RF power amplifier. The adaptive bias circuit includes means for providing the driving current to the bias circuit and means for drawing a bypass current from the providing means to reduce the driving current in response to the input signal, wherein the quiescent current is reduced when the driving current is reduced and the bypass current increases when the input signal is reduced.

Adaptive bias circuit for a power amplifier

A power amplifier for use in a mobile handset includes an amplifying transistor for generating an output of the mobile handset, a bias circuit having a bias transistor and providing a bias current to bias the amplifying transistor, and a bias current control circuit, responsive to a control signal, for adjusting the bias current to control an operation current of the amplifying transistor. The control signal is generated by the mobile handset, and the control signal is determined by a power level of the output of the mobile handset.

Power amplifier having a bias current control circuit

A bias control circuit for a power amplifier including an RF amplifier having a transistor for power amplification, comprises two components. A first component is a bias circuit having an active bias transistor operating in an active mode and connected to a predetermined Vref pin to provide the transistor for power amplification with a base current and a second component is a bias current control circuit having another active bias transistor connected to a predetermined Vcon pin and turned on or off depending on a high or a low mode of the Vcon pin to thereby control a base current and a quiescent current of the transistor for power amplification.

Growing community of inventors

Daejeon, South Korea

Youn Sub Noh