Samsung Electronics Co., Ltd.

Postech Academy-industry Foundation

Postech Foundation

Bum-Man Kim

Dong-Geun Lee

Han-Seok Kim

Young-Eil Kim

Heung-bae Lee

Sang-yoon Jeon

Ick-jin Kwon

Young-Yoon Woo

Jung-Hwan Moon

Cheol-Soo Seo

Jin-soo Park

Hyung-sun Lim

Jeong-Hyeon Cha

Sang-Wook Kwon

Sung-Bum Park

Sung-Ku Yeo

Tae-Young Chung

Jin-Sung Kim

Jaesup Lee

Cheol-Woo Ahn

Il-Du Kim

Dae-Chul Jeong

Keun-Hyo Song

Chang-joon Park

Young-Yun Woo

Jang-Heon Kim

Yun-Sik Park

Jung-Joon Kim

Dong-Gyu Min

Je-hyung Yoon

A power amplifier may comprise: an element for amplifying an electrical signal received through an input terminal, and outputting the amplified electrical signal through an output terminal; a first impedance adjustment circuit connected to the input terminal of the element and adjusting impedance with respect to a frequency of a fundamental component at the input terminal; a second impedance adjustment circuit connected to the input terminal of the element and adjusting impedance with respect to a frequency of a multiplied harmonic component at the input terminal; a third impedance adjustment circuit connected to the output terminal of the element and adjusting impedance with respect to the frequency of the fundamental component at the output terminal; a fourth impedance adjustment circuit connected to the output terminal of the element and adjusting impedance with respect to the frequency of the multiplied harmonic component at the output terminal; a first frequency separation circuit which prevents an impedance change by the first impedance adjustment circuit with respect to the frequency of the multiplied harmonic component at the input terminal, and prevents an impedance change by the second impedance adjustment circuit with respect to the frequency of the fundamental component at the input terminal; and a second frequency separation circuit which prevents an impedance change by the third impedance adjustment circuit with respect to the frequency of the multiplied harmonic component at the output terminal, and prevents an impedance change by the fourth impedance adjustment circuit with respect to the frequency of the fundamental component at the output terminal.

Power amplifier and impedance adjustment circuit

A leakage current-based delay circuit is provided, wherein the delay circuit may include a first transistor circuit and a second transistor circuit, each transistor circuit may include a p-type transistor, an n-type transistor, an n-node between a drain node of the p-type transistor and a gate node of the n-type transistor, and a p-node between a gate node of the p-type transistor and a drain node of the n-type transistor. The p-node of the second transistor circuit may be charged based on a power source voltage through the first transistor circuit during a first time interval of an input signal, and the n-node of the second transistor circuit may be discharged based on a ground voltage through the first transistor circuit during the first time interval.

Leakage current-based delay circuit

A radio frequency (RF) receiver and a method of receiving an RF signal are provided. The RF receiver includes a low-noise amplifying unit which amplifies a received signal while restricting out-of-band interference of the received signal, a sampling unit which performs sampling to convert the amplified signal to a discrete time domain signal, a frequency translation unit which down-converts the discrete time domain signal into a frequency band that enables the discrete time domain signal to be converted into a digital signal and restricts interference from a frequency within an aliasing band according to a sampling frequency, an anti-aliasing filtering unit which prevents aliasing from the down-converted signal, a clock unit which provides the sampling unit, the frequency translation unit, and the anti-aliasing filtering unit with sampling frequencies, and an analog-digital-converter which converts the converted signal into the digital signal.

RF receiver and method to receive, amplify, sample, down convert, anti-aliasing filter, and ADC convert an RF signal

A method and apparatus improve the performance of a carrier amplifier in a Doherty amplifier. The Doherty amplifier includes a power divider, a carrier amplifier, at least one peaking amplifier, offset lines, and a Doherty circuit. The power divider provides a power signal to each of the carrier amplifier and the at least one peaking amplifier. The carrier amplifier amplifies power of a signal inputted from the power divider. The at least one peaking amplifier amplifies power of a signal inputted from the power divider. The offset lines control a load impedance when the at least one peaking amplifier does not operate. When the at least one peaking amplifier does not operate, the Doherty circuit generates the load impedance of the carrier amplifier that is larger than twice a load impedance at the maximum output power of the carrier amplifier.

Apparatus for improving performance at low power region in a Doherty amplifier

An apparatus and a method for an Envelope Elimination and Restoration (EER) power transmitter are provided. The apparatus includes a signal separator for splitting a transmit signal to an amplitude component and a phase component, an orthogonal modulator for modulating the phase component into a Radio Frequency (RF) signal, a bias modulator for linearly amplifying the amplitude component, for determining a bias voltage according to a magnitude of the amplitude component, and for providing a current generated using the determined bias voltage to a high-efficiency power amplifier and the high-efficiency power amplifier for amplifying the RF signal using the linearly amplified amplitude component as a drain bias voltage and using the generated current as a drain bias current.

Apparatus and method for power transmitter in wireless communication system

A saturated power amplification apparatus and a method for controlling the same are provided, in which a power device is provided, and an output matcher matches a load impedance of the power device. The load impedance is a complex impedance exceeding an impedance generated during power matching in the saturated power amplification apparatus.

High-efficiency power amplification apparatus using saturated operation and method for controlling the same

An envelope elimination and restoration power transmission apparatus in a wireless communication system is provided. The apparatus comprises a signal processor for dividing a transmission signal into a size component and a phase component and for generating a control signal for controlling a current of a bias modulator according to the size component, the bias modulator for amplifying the size component according to the control signal supplied from the signal processor, for lowering an impedance characteristic of the amplified size component and for outputting the amplified size component, a frequency modulator for modulating the phase component into a radio frequency (RF) signal, and a power amplifier for amplifying the RF signal by using an output signal of the bias modulator as a bias voltage. As provided, the transmission apparatus reduces a memory effect due to an impedance difference in a modulation frequency band.

Power transmission apparatus in wireless communication systems

A low noise amplifier is provided. The low noise amplifier includes: a low noise amplifying unit amplifying an input signal; a harmonic and noise generating unit disposed in an input terminal of the low noise amplifying unit, for generating a compensating signal for compensating for an intermodulation distortion signal and a thermal noise signal of the input signal to the low noise amplifying unit; and a load unit outputting the amplified input signal generated by the low noise amplifying unit.

Low noise amplifier

An method and apparatus for power amplification in a mobile communication system, wherein a signal converter for receives signals from a baseband-side, modulates the received signals into oversampled baseband digital signals, and generates signals having a constant envelope with the oversampled base band digital signals, an up-converter up-converts the generated signals having the constant envelope to Radio Frequency (RF) signals for output, and a power amplifier amplifies the RF signals according to system setup levels and outputs envelope signals of a predetermined level.

Apparatus and method for high efficiency power amplification for a mobile communication system

An apparatus and method amplifies a delta-sigma modulated signal and delivers the amplified signal to a power amplifier without distortion in a communication system. The apparatus receives a delta-sigma modulated signal, phase-delays the received delta-sigma modulated signal by a multiple of 360&#xb0; for a bandwidth of the delta-sigma modulated basic signal, and amplifies the phase-delayed signal, facilitating implementation of a high-efficiency delta-sigma modulation-based amplification system.

Input matching apparatus and method for power amplifier using delta-sigma modulated signal

Growing community of inventors

Pohang-si, South Korea

Bum-Man Kim