Abstract: A method and apparatus for input matching of a passive mixer are disclosed. The passive mixer includes a differential transistor pair including a first transistor and a second transistor, a first inductor having one end connected to the first transistor and another end connected to a ground, a second inductor having one end connected to the second transistor and another end connected to a ground, and a third inductor having one end for receiving a radio frequency (RF) signal and another end connected to a ground.

Abstract: A differential transmission line having a switch may comprise: a first transmission line comprising a first distribution element having a first impedance; a second transmission line comprising a second distribution element having a second impedance; and a first switch block connected between a first end of the first transmission line and a first end of the second transmission line, wherein the first switch block comprises a first switch connected in series to the first end of the first transmission line, a second switch connected in series to the first end of the second transmission line, a first-cross capacitor connected between a first terminal of the first switch and a second terminal of the second switch, and a second cross-capacitor connected between a first terminal of the second switch and a second terminal of the first switch.

Abstract: Provided is a terahertz wideband antenna and a method for designing the same. According to various embodiments, the wideband antenna used for mobile communication in the terahertz wave communication band may include an antenna board including a first surface and a second surface opposite to the first surface, and a plurality of dipole antennas arranged on the antenna board, each of the plurality of dipole antennas may include a feeder disposed on the first surface and a radiator disposed on the second surface and physically spaced apart from the feeder, the feeder may be wire-bonded to a corresponding channel of a plurality of channels of a beam former, and the radiator may be coupled to the feeder to receive a signal from the feeder.

Abstract: Disclosed is a bidirectional amplifier. The bidirectional amplifier includes a first matching circuit, a second matching circuit, an amplifier circuit connected between the first matching circuit and the second matching circuit, that amplifies a first input signal received from the first matching circuit to output the amplified first input signal to the second matching circuit, and that amplifies a second input signal received from the second matching circuit to output the amplified first input signal to the first matching circuit, and the first and second matching circuits have a symmetrical structure and operate complementary to each other.

Abstract: An array antenna system, and a calibration method and apparatus thereof are provided. The calibration method includes measuring a signal loop including mutual coupling between antennas included in an array antenna, calculating a ratio of a reception (RX) signal received by each antenna to an RX signal received by a reference antenna of the array antenna based on a result of the measuring, and performing calibration of the array antenna based on the ratio.

Abstract: Provided are a semiconductor-based temperature sensor and a method of operating the semiconductor-based temperature sensor. A temperature sensor includes an electrical temperature signal generator configured to generate a first electrical temperature signal that changes according to temperature and a second electrical temperature signal that changes according to temperature at a different rate from that of the first electrical temperature signal, a differential signal generator configured to generate a differential electrical temperature signal between the first electrical temperature signal and the second electrical temperature signal, and an analog digital converter (ADC) configured to convert the differential electrical temperature signal into digital temperature information.

Abstract: A method and apparatus for input matching of a passive mixer are disclosed. The passive mixer includes a differential transistor pair including a first transistor and a second transistor, a first inductor having one end connected to the first transistor and another end connected to a ground, a second inductor having one end connected to the second transistor and another end connected to a ground, and a third inductor having one end for receiving a radio frequency (RF) signal and another end connected to a ground.

Abstract: A transformer-based amplifier, an operating method thereof, and devices including the same are disclosed. A millimeter wave amplifier includes a first transformer positioned on an input side of the millimeter wave amplifier, a second transformer positioned on an output side of the millimeter wave amplifier, and one or more of amplification stages positioned between the first transformer and the second transformer.

Abstract: An amplifier may comprise first and second matching networks; first and second transistors; and a transformer including first to third inductors. Also, a gate and a source of the first transistor are connected to the first matching network, one end of the first inductor is connected to a drain of the first transistor, the other end of the first inductor is connected to a source of the second transistor, one end of the second inductor is connected to a gate of the second transistor, the other end of the second inductor is grounded, one end of the third inductor is connected to a drain of the second transistor, and the other end of the third inductor is connected to the second matching network.

Abstract: An array antenna system, and a calibration method and apparatus thereof are provided. The calibration method includes measuring a signal loop including mutual coupling between antennas included in an array antenna, calculating a ratio of a reception (RX) signal received by each antenna to an RX signal received by a reference antenna of the array antenna based on a result of the measuring, and performing calibration of the array antenna based on the ratio.

Abstract: High frequency signal amplifier including balun is disclosed. The amplifier comprises an input terminal (Vin) through which the high frequency signal is input; a balun which is connected to the input terminal and outputs a first differential signal and a second differential signal based on the high frequency signal; a transistor (M) which is connected to the balun and outputs an amplified high frequency signal based on the first differential signal and the second differential signal; an output terminal which is connected to the transistor (M) and through which the amplified high frequency signal is acquired and the amplified high frequency signal is output. Therefore, performance of the amplifier can be enhanced.

Abstract: An amplifier may comprise first and second matching networks; first and second transistors; and a transformer including first to third inductors. Also, a gate and a source of the first transistor are connected to the first matching network, one end of the first inductor is connected to a drain of the first transistor, the other end of the first inductor is connected to a source of the second transistor, one end of the second inductor is connected to a gate of the second transistor, the other end of the second inductor is grounded, one end of the third inductor is connected to a drain of the second transistor, and the other end of the third inductor is connected to the second matching network.

Abstract: A transmitting and receiving switch, a transmitting and receiving apparatus, and an operating method of a transmitting and receiving switch are disclosed. The transmitting and receiving switch may include a first switch configured to be connected between the transmitting front-end module and the antenna, a second switch configured to be connected between the receiving front-end module and a ground, and a first inductor configured to be connected between the second switch and the antenna, a second inductor configured to be connected between the antenna and the ground, and a variable capacitor configured to be connected between the antenna and the ground.

Abstract: Disclosed are a method for signal modulation based on pulse density modulation and an apparatus therefore. The method for signal modulation is performed in an apparatus for modulating a signal based on pulse density modulation and includes performing pulse density modulation on an analog signal input to the apparatus through a pulse density modulator of the apparatus, converting a bandwidth of the pulse density modulated signal into a bandwidth required for the apparatus through a correlative encoder of the apparatus, transmitting the bandwidth converted signal to a radio frequency (RF) unit of the apparatus based on an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter of the apparatus, filtering a frequency band of the bandwidth converted signal and outputting the frequency band filtered signal via the RF unit.

Abstract: A matching circuit in a communication apparatus may comprise a first inductor disposed at a primary side of a transformer; a second inductor disposed at a secondary side of the transformer; and an impedance element connected to the first inductor and the second inductor. Also, a first terminal of the first inductor may be connected to an input terminal of the transformer, a second terminal of the first inductor may be connected to a common node connected to a ground, a first terminal of the second inductor may be connected to an output terminal of the transformer, a second terminal of the second inductor may be connected to the common node, a first terminal of the impedance element may be connected to the common node, and a second terminal of the impedance element may be connected to the ground.

Abstract: High frequency signal amplifier including balun is disclosed. The amplifier comprises an input terminal (Vin) through which the high frequency signal is input; a balun which is connected to the input terminal and outputs a first differential signal and a second differential signal based on the high frequency signal; a transistor (M) which is connected to the balun and outputs an amplified high frequency signal based on the first differential signal and the second differential signal; an output terminal which is connected to the transistor (M) and through which the amplified high frequency signal is acquired and the amplified high frequency signal is output. Therefore, performance of the amplifier can be enhanced.

Abstract: Disclosed are a method for signal modulation based on pulse density modulation and an apparatus therefore. The method for signal modulation is performed in an apparatus for modulating a signal based on pulse density modulation and includes performing pulse density modulation on an analog signal input to the apparatus through a pulse density modulator of the apparatus, converting a bandwidth of the pulse density modulated signal into a bandwidth required for the apparatus through a correlative encoder of the apparatus, transmitting the bandwidth converted signal to a radio frequency (RF) unit of the apparatus based on an electrical-to-optical (E/O) converter and an optical-to-electrical (O/E) converter of the apparatus, filtering a frequency band of the bandwidth converted signal and outputting the frequency band filtered signal via the RF unit.

Abstract: A data modulation apparatus may comprise a S2D conversion part including a first amplifier operating based on a carrier wave signal and two transformers receiving an output signal of the first amplifier; a first switch part transferring status of input data to the first amplifier based on the input data; a differential amplification part receiving output signals of the S2D conversion part and amplifying the output signals of the S2D conversion part; a D2S conversion part receiving output signals of the differential amplification part and performing modulation on the output signals by converting the output signals to a single signal; and a second switch part transferring the output signals of the differential amplification part to the D2S conversion part based on the input data. Here, the first switch part and the second switch part may be alternately turned on and off.

Abstract: A high frequency amplifier circuit includes a transistor including a drain, a gate, and a source, an inductance-capacitor (LC) tank connected to the drain, and a transformer connected to the gate and the source.

Abstract: An envelope signal time delay adjustment apparatus includes a negative group delay unit for converting an envelope signal input from a signal generator into an envelope signal having a group delay of a negative value whose frequency increases from a predetermined frequency band; an envelope-tracking modulator for power-amplifying and outputting the envelope signal output from the negative group delay unit; and a frequency limiting unit for limiting a bandwidth of the envelope-tracking modulator to be lower than an original bandwidth of the envelope-tracking modulator.