Korea Advanced Institute of Science and Technology

Samsung Electronics Co., Ltd.

Electronics and Telecommunications Research Institute

Song-cheol Hong

In-sang Song

Jinseok Park

Jeong-geun Kim

Jin-seok Park

Seung-hun Wang

Seung-hoon Kang

Se-Ho Park

Sang-Wook Kwon

Seong-soo Lee

Sung-Ku Yeo

Yong-hoon Kim

Dong-kyun Kim

Min Sang Park

Dong-Geun Lee

Mi-Hyun Son

Jae-Sup Lee

Cheon-Soo Kim

Byung-Tae Yoon

Jae-Hun Lee

Min-Cheol Ha

Dong-Woo Kang

Ju-Hyun Ko

Hyun-Il Kang

Jong-Wook Zeong

Sang-soo Ko

Choul-Young Kim

Jang-Hong Choi

Dong-Hyun Baek

Hong-chan Kim

Baek-Hyun Kim

Duk-Ju Ahn

Gwang-Hyeon Jeong

Holger Lothar

A calibration circuit includes a selection unit, a power detector, an analog-to-digital converter and a calibrator. The selection unit is connected to the plurality of channels, selects two channels from among the plurality of channels, provides a test signal to the selected two channels, and receives a test result signal from the selected two channels. The power detector detects power of the selected two channels. The analog-to-digital converter performs an A/D conversion on an output of the power detector. The calibrator calibrates the phases and the gains between the plurality of channels based on an output of the analog-to-digital converter. One of the plurality of channels is set as a reference channel, phases and gains of remaining channels other than the reference channel among the plurality of channels are sequentially optimized based on the reference channel, and a phase and a gain of the reference channel is optimized.

Calibration circuit for calibrating phases and gains between channels in multi-channel beamforming system, multi-channel beamforming system including the same and channel calibration method using the same

A variable gain phase shifter includes an I/Q generator and a vector summation circuit. The I/Q generator generates phase signals based on an input signal. The vector summation circuit adjusts magnitudes and directions of first, second, third and fourth in-phase vectors and first, second, third and fourth quadrature vectors, and generates an output signal by summing the in-phase vectors and the quadrature vectors, based on the phase signals, selection signals and current control signals. The vector summation circuit includes first, second, third and fourth vector summation cells and first, second, third and fourth current control circuits. The first and second vector summation cells adjust the directions of the first and second in-phase vectors and the first and second quadrature vectors. The third and fourth vector summation cells adjust the directions of the third and fourth in-phase vectors and the third and fourth quadrature vectors. The first and second current control circuits are connected to the first and second vector summation cells, and adjust an amount of a first current and an amount of a second current. The third and fourth current control circuits are connected to the third and fourth vector summation cells, and adjust an amount of a third current and an amount of a fourth current.

Variable gain phase shifter

A beam-forming circuit includes a multi mode power amplifier, a variable gain low noise amplifier, a variable gain phase shifter and a first switch circuit. The multi mode power amplifier amplifies a first RF intermediate signal generated based on a first RF input signal to generate a first RF output signal and performs a first transmission gain adjustment function based on a first control signal in a transmission mode. The variable gain low noise amplifier amplifies a second RF input signal to generate a second RF intermediate signal and performs a first reception gain adjustment function based on a second control signal in a reception mode. The variable gain phase shifter controls a gain and a phase of the first RF input signal at one time to generate the first RF intermediate signal and performs a second transmission gain adjustment function and a transmission phase adjustment function at one time based on a third control signal in the transmission mode, and controls a gain and a phase of the second RF intermediate signal at one time to generate a second RF output signal and performs a second reception gain adjustment function and a reception phase adjustment function at one time based on the third control signal in the reception mode. The first switch circuit receives the first RF input signal in the transmission mode, and outputs the second RF output signal in the reception mode.

Beam-forming circuit for 5G mobile communication and radar

A wireless electric power transmitter for transmitting electric power for a charging function to a wireless electric power receiver is provided. The wireless electric power transmitter includes an electric power supply unit which supplies electric power; an amplifier which amplifies and outputs the electric power supplied from the electric power supply unit by a preset gain as a magnitude of measured impedance increases; and a transmitter which transmits the amplified electric power to the wireless electric power receiver.

Wireless electric power transmitter

Provided is a power amplifier installed in wireless communication terminals and systems. According to one aspect of the present invention, a reconfigurable power amplifier capable of selecting a wide band frequency is provided. The reconfigurable power amplifier includes input transistors receiving a radio frequency (RF) signal and a reconfigurable adaptive power cell configured to select the wide band frequency by applying a common-gate bias voltage to a plurality of common-gate transistors with a plurality of separate common gates to amplify the RF signal.

Reconfigurable power amplifier capable of selecting wide band frequency and method for selecting wide band frequency

Provided is a method in which a Digital Pre-Distorter (DPD) performs digital pre-distortion on a received In-phase (I) signal, a received Quadrature-phase (Q) signal, a feedback I signal, and a feedback Q signal; a mixer mixes a signal output from the DPD with a frequency signal output from an oscillator; each of n phase shifters phase-shifts a signal output from the mixer according to a preset beamforming pattern; each of n Power Amplifiers (PAs) amplifies a signal output from an associated phase shifter according to a gain, the PAs connected to the associated phase shifter on a one-to-one basis; each of n envelope detectors detects an envelope signal from a signal output from an associated PA, the envelope detector connected to the associated PA on a one-to-one basis; and a control unit determines whether the n PAs operate normally, using the envelope signals output from the n envelope detectors.

Apparatus for compensating for distortion of transmitter array in radio communication system and method for controlling the same

A quadrature radar apparatus includes a quadrature signal generating unit, a plurality of coupler modules connected to the signal generating unit, an antenna unit receiving transmission signals from the coupler modules and a reception signal reflected from a target, one or more phase delay modules connected between one or more of the coupler modules and the antenna unit to delay the phases of the transmission and reception signals by 90 degrees, a leakage signal canceling unit combining the reception signals inputted from the antenna unit through the first and second coupler modules and removes the transmission leakage signal.

Quadrature radar apparatus

A radar system includes a transmitter stage for generating a certain transmission signal; a circularly polarized antenna for emitting the transmission signal in a form of a circularly polarized signal, and receiving a reflection signal; a polarizer for isolating the reflection signal received from the circularly polarized antenna from the transmission signal, and outputting the reflection signal to a next stage; and a receiver stage for receiving the reflection signal output from the polarizer, converting the reflection signal into a signal of a certain frequency by using as a certain mixer switching signal the leakage signal leaking from the transmitter stage, and outputting the converted reflection signal. Therefore, the high-sensitivity radar system can be built in a compact size.

Radar system having single circularly polarized antenna

A small-sized on-chip complementary metal-oxide semiconductor (CMOS) Power Amplifier having improved efficiency is provided herein. The on-chip CMOS power amplifier is capable of improving efficiency and maximizing output thereof by enhancing a K factor, which may cause a problem in a power amplifier having a distributed active transformer structure. The on-chip CMOS power amplifier having an improved efficiency and being fabricated in a small size, the on-chip CMOS power amplifier includes a primary winding located at a first layer, secondary windings located at a second layer, which is an upper part of the first layer, the secondary windings being located corresponding to a position of the primary winding, and a cross section for coupling the second windings with each other.

Small-sized on-chip CMOS power amplifier having improved efficiency

A radar system using a quadrature signal includes a quadrature push&#x2014;push oscillator for generating four harmonics with a 90-degree phase difference from each other, and producing two-balanced 2harmonic signals from the harmonics; a first coupler block for radiating one of the 2harmonics through an antenna; a second coupler block for terminating the other 2harmonic to ground; and a power combiner for combining a transmitted signal that is leaked from the first and second coupler blocks with the received signal that is radiated through the antenna. The radar system features an improved receiving sensitivity by offsetting the leakage signals of the sending end. Also, the radar system can be made very small by using a single antenna for transmitting and receiving.

Radar system using quadrature signal

Growing community of inventors

Daejeon, South Korea

Song-cheol Hong