Abstract: Provided are a nitride-based high electron mobility transistor having enhanced frequency characteristics and an improved structural stability and manufacturing method thereof. The nitride-based high electron mobility transistor includes a first semiconductor layer and a second semiconductor layer sequentially formed on a substrate, source drain electrodes formed on the second semiconductor layer, a first insulating film formed on the second semiconductor layer and having an opening, a dielectric formed on the first insulating film to surround the opening of the first insulating film, a second insulating film formed on an inner sidewall of the dielectric, and a gate electrode formed on the dielectric to fill the opening of the first insulating film and inside the inner sidewall of the dielectric. A width of the inner sidewall at a bottom end of the dielectric is smaller than a width of the inner sidewall at a top end of the dielectric.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a single pole double through (SPDT) switch including a series switching unit including first and second series switching elements commonly connected to a common input port, and a shunt switching unit including a plurality of shunt switching elements connected in parallel to a first signal path connecting the common input port to a first output port and a second signal path connecting the common input port to a second output port, wherein first and second inductors are respectively connected to gate terminals of the first and second series switching elements.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a bias circuit. The bias circuit includes: a first resistor connected between a ground terminal and a first node; a first bias transistor having a drain connected to the first node and a source connected to a second node; a second bias transistor having a drain connected to the second node and a source connected to a negative voltage terminal; a third bias transistor having a drain connected to the ground terminal and a source connected to a third node; and a second resistor connected between the third node and the negative voltage terminal, wherein a gate of the first bias transistor is connected to the second node; a gate of the second bias transistor is connected to the negative voltage terminal; a gate of the third bias transistor is connected to the first node; and a gate bias voltage signal is outputted through the third node.

Abstract: 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.

Abstract: A transmit/receive module for radar may include a radio frequency (RF) circuit unit including an RF substrate and an RF part; and a direct current (DC) power supply circuit unit including a printed circuit board (PCB) and a DC power supply circuit part. The RF circuit unit and the DC power supply circuit unit may be disposed so that a rear surface of the RF circuit unit faces a rear surface of the DC power supply circuit unit, and may be assembled to have a separate space using at least one separation wall.

Abstract: An apparatus for controlling an amplifier in a communication system includes a first shifter, a generating unit, a second shifter, and a switching bias unit. The first shifter is configured to level-shift a switching voltage of an amplifier to a first voltage. The generating unit is configured to invert the first voltage and output a second voltage. The second shifter is configured to level-shift the second voltage to a third voltage. The switching bias unit is configured to receive the third voltage and output a bias voltage for a gate switching operation of the amplifier to the amplifier.

Abstract: Provided is a compact RF power amplifier including: a Doherty amplifier comprising a carrier amplifier comprising a first input impedance matching unit, a first amplifier, and a first output impedance matching unit, and a peaking amplifier comprising a second input impedance matching unit, a second amplifier, and a second output impedance matching unit, in which when a power level of the first RF amplified signal reaches a predetermined power level, the peaking amplifier outputs the second RF amplified signal.

Abstract: 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.

Abstract: A coupled line filter includes: a first line resonator connected input port and a second line resonator connected with output port each having an electrical length of 270° at a predetermined center frequency, the first and second line resonators being disposed parallel to each other; and a third line resonator including one or more line resonators disposed between the first line resonator and the second line resonator, each line resonator having an electrical length of 90° at the center frequency and a first side aligned with first sides of the first line resonator and the second line resonator, wherein an order of the coupled line filter is determined by summing the number of the line resonators included in the third line resonator and the first and second line resonators.

Abstract: 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.

Abstract: An apparatus for controlling an amplifier in a communication system includes a first shifter, a generating unit, a second shifter, and a switching bias unit. The first shifter is configured to level-shift a switching voltage of an amplifier to a first voltage. The generating unit is configured to invert the first voltage and output a second voltage. The second shifter is configured to level-shift the second voltage to a third voltage. The switching bias unit is configured to receive the third voltage and output a bias voltage for a gate switching operation of the amplifier to the amplifier.

Abstract: 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.

Abstract: 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.

Abstract: A coupled line filter includes: a first line resonator connected input port and a second line resonator connected with output port each having an electrical length of 270° at a predetermined center frequency, the first and second line resonators being disposed parallel to each other; and a third line resonator including one or more line resonators disposed between the first line resonator and the second line resonator, each line resonator having an electrical length of 90° at the center frequency and a first side aligned with first sides of the first line resonator and the second line resonator, wherein an order of the coupled line filter is determined by summing the number of the line resonators included in the third line resonator and the first and second line resonators.

Abstract: Provided are a low-temperature-cofired-ceramic (LTCC) package and a method of manufacturing the same. The LTCC package includes: an LTCC substrate including a plurality of LTCC layers and a recess in which a device is mounted; a thermal conductive element adhered onto a first LTCC layer exposed by the recess using a first thermal conductive adhesive member; the device adhered onto the thermal conductive element using a second thermal conductive adhesive member; and a connection member for electrically connecting the device with the LTCC substrate. In the LTCC package and the method, portions of the LTCC layers disposed under a high-heating device except a lowermost LTCC layer contacting a heat sink, which correspond to a thermal transmission path, are removed and replaced by a higher thermal conductive material to minimize heat dissipation resistance and heat resistance caused by thermal conduction.

Abstract: A broadband active balun using reactive feedback and a balanced mixer using the balun are provided. The broadband active balun comprises a common gate FET having a source connected to an input terminal, a gate connected to the ground, and a drain connected to a first output terminal; a reactive impedance element having one end connected to the drain of the common gate FET and the other end connected to one of the gate and the source of the common gate FET, and a common source FET having a gate connected to the input terminal, a source connected to the ground and a drain connected to a second output terminal. Accordingly, the active balun has a small physical size and a wide frequency band.