Abstract: Provided is a frequency mixer including: an oscillator configured to output an LO signal; a first converter configured to convert an input IF signal into different first and second IF signals; a first mixer configured to output a first RF signal in which the first IF signal is mixed with the LO signal and a first leakage signal; a second mixer configured to output a second RF signal in which the second IF signal is mixed with the LO signal and a second leakage signal; and a second converter configured to mix and attenuate the first and second leakage signals and output an RF signal in which the first and second RF signals are mixed, in order to minimize leakage power of an LO signal generated in a local oscillator in a transmitter for a communication system using a high frequency of 70 GHz or higher, such as an E-band.

Abstract: A frequency mixing apparatus includes a local oscillator, a signal distributor, a first frequency mixer and a second frequency mixer and a combiner. The signal distributor divides a signal generated from the local oscillator into two signals having a phase difference and outputs the two signals. The first frequency mixer has a first input port through which one of the two signals outputted through the signal distributor is inputted and a second input port connected to an RF signal. The a second frequency mixer has a first input port through which one of the two signals outputted through the signal distributor and a second input port is connected to a termination signal. The combiner combines signals respectively outputted from the first and second frequency mixers.

Abstract: A multiport amplifier modulates a reference quadrature phase shift keying (QPSK) signal using an input RF signal to an input hybrid network, generates a plurality of binary phase shift keying (BPSK) signals by demodulating RF signals that are amplified by a plurality of power amplifiers, detects an amplitude error and a phase error of two corresponding amplified RF signals by comparing a QPSK signal that is generated by coupling two RF signals having a phase difference of 90° among the plurality of BPSK signals with a reference QPSK signal, and compensates the detected amplitude error and phase error.

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: Disclosed are an apparatus and a method of tuning a microwave filter. An apparatus for tuning a microwave filter according to the present invention includes: a measurement device configured to measure a scattering (S) parameter curve of a microwave filter desired to be tuned; a control device configured to perform tuning so that a shape of the S parameter curve according to a movement of a preselected tuning screw is matched to a shape of a target S parameter curve, and then determine a quantity of transfer of the tuning screw based on feature points on the S parameter curve by using a least squares method in which a preset weight is reflected; and a tuning device configured to move the tuning screw based on the determined quantity of transfer of the tuning screw.

Abstract: Provided is a 3-way balun for a double balanced mixer. This research provides a 3-way balun available for a planar-type double balanced mixer and a planar-type double balanced mixer employing the same. The 3-way balun includes a first output unit for receiving and outputting an input signal of a predetermined frequency; and second and third output units connected to the first output unit and outputting signals whose phase is different by 180 from a phase of a signal of the first output unit and amplitude is a half of an amplitude of the signal outputted from the first output unit.

Abstract: Disclosed is an apparatus and a method for multiport amplification configured to amplify a signal input to a multi-input port and output the amplified signal to a multi-output port in order to normally transmit/receive a signal in a communication system. The apparatus and the method are configured to: amplify an input signal input through a multi-input port, detect a phase error and an amplitude error of the input signal, and then calculate a phase error value and an amplitude error value of the input signal; correct the phase error and the amplitude error of the input signal through the phase error value and the amplitude error value of the input signal; and then amplify the input signal of which the phase error and the amplitude error are corrected, and output the input signal to a multi-output port.

Abstract: Provided is a RF switch for switching a path of a RF signal using a semiconductor transistor such as a field effect transistor (FET). The RF switch includes a plurality of resonators connected to a RF transmission line, and at least one of switching elements connected in shunt or in series between the plural of resonators. The plurality of resonators resonate by interacting with the switching elements when the switching elements are shorted or open.

Abstract: Provided is a power amplifier used in a transmitter of a communication system. The power amplifier may include a power amplifier module to amplify power of a transmitting signal, an energy converter module to receive thermal energy generated by the power amplifier module and to convert the received thermal energy into electric energy, and a direct current (DC)-DC converter module to produce DC power using the electric energy generated by the energy converter module and to supply the produced DC power to the power amplifier module.

Abstract: Provided is an antenna apparatus which employs a small number of antenna devices and is intended to obtain a desired pattern without adjusting current level and phase of each antenna device. The antenna apparatus includes a first ridge horn antenna, and a second ridge horn antenna spaced apart from the first ridge horn antenna by a predetermined distance. Here, a multi-beam pattern is generated using a third-order mode beam pattern of a synthetic beam obtained by synthesizing beams respectively radiated from the first and second ridge horn antennas. Accordingly, the antenna apparatus can be simplified, and a desired multi-beam pattern can be obtained without adjusting signal level and phase of each antenna device. Also, by employing the ridge horn antennas as array devices, the antenna apparatus can be used in a wide frequency band.

Abstract: A system for controlling temperature of an antenna module including a heat generating module, and a radome and an underbody cover that enclose the heat generating module. The system includes: a heat collecting unit mounted on inner surface of the antenna module; a heat discharging unit mounted on outer surface of the antenna module; and a heat transfer unit for transferring heat from the heat collecting unit to the heat discharging unit.

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: The present invention relates to an antenna system mounted on a mobile vehicle. In the present invention, a power distributor and a part of a high-frequency module that includes a frequency converter are placed in an external fixed unit that is placed outside a radome. In addition, an active cooler/cooling fin, a heater, and an air circulation fan are placed at an internal bottom plane of the antenna system, and a cooling fin and cooling fan are placed at an external bottom plane of the antenna system.

Abstract: A butler matrix includes at least one input coupler that is positioned at an input end of the butler matrix, receives an input signal, and divides and outputs it to a plurality of paths, and at least one output coupler that receives a signal from the input coupler and divides the signal into a plurality of paths to output it as an output signal. A separation coupler is formed in an intersecting path including an intersecting section at which transmission paths intersect among a plurality of paths through which a signal is transmitted to separate signals transmitted through different transmission paths. Further, a compensation coupler is formed in a path excluding the intersecting path to compensate a phase difference.

Abstract: An ultra wideband hermetically sealed surface mount package for a microwave monolithic integrated circuit (MMIC) is provided including: an integrated circuit; a package body being mounted with the integrated circuit and comprising a plurality of first dielectrics formed in a multilayer, a first line unit mounted to a circuit substrate and is electrically connected with an external circuit, a second line unit upwardly extended from the first line unit and is electrically connected with the first line unit, a third line unit extended to the right angle from the second line unit and is electrically connected with the second line unit, and a bonding unit that electrically connects the third line unit and the mounted integrated circuit; and a package cover being formed on the package body to seal the integrated circuit and comprising a plurality of second dielectrics formed in a multilayer.

Abstract: Provided is a marchand balun device. The marchand balun device includes: a first line connected between a balanced terminal and a ground terminal; a second line disposed horizontally parallel to the first line and forming a parallel capacitance jointly with the first line; and a coupled line disposed vertically parallel to the first and second lines and forming a vertical capacitance jointly with one of the first and second lines.

Abstract: There is provided a frequency Selective Surface (FSS) structure for multi frequency bands configured with unit cells, each including a loop unit, arranged at regular intervals, wherein each unit cell includes: a dielectric layer; and the loop unit having a fixed width and formed on the dielectric layer, wherein the loop unit includes a first loop and a second loop formed inside the first loop with a predetermined space away from the first loop, each of the first loop and the second loop being formed sinuously in at least one portion.

Abstract: A multiport amplifier modulates a reference quadrature phase shift keying (QPSK) signal using an input RF signal to an input hybrid network, generates a plurality of binary phase shift keying (BPSK) signals by demodulating RF signals that are amplified by a plurality of power amplifiers, detects an amplitude error and a phase error of two corresponding amplified RF signals by comparing a QPSK signal that is generated by coupling two RF signals having a phase difference of 90° among the plurality of BPSK signals with a reference QPSK signal, and compensates the detected amplitude error and phase error.

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 a high-power device having a thermocouple (thermoelectric couple) for measuring the temperature of a transistor constituting a high-power device. The high-power device includes a heating element, a thermocouple formed adjacent to the heating element, and a dielectric body formed between the heating element and the thermocouple.