Samsung Electronics Co., Ltd.

Postech Academy-industry Foundation

Postech Foundation

Cheol-Soo Seo

Bum-Man Kim

Young-Yoon Woo

Cheol-Woo Ahn

Jung-Hwan Moon

Il-Du Kim

Keun-Hyo Song

Jang-Heon Kim

Jung-Joon Kim

Young-Yun Woo

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

A Radio Frequency (RF) front-end apparatus in a wireless communication system is provided. The apparatus includes a plurality of BandPass Filters (BPFs) for band-pass filtering a transmission signal or a reception signal, at least one circulator for dividing a signal transmission path and a signal reception path and at least one switch for controlling the signal transmission path and the signal reception path. The RF front-end apparatus provided by the present invention supports various frequency bands and optionally supports TDD and FDD in a wireless communication system.

Apparatus for optionally supporting time division duplex and frequency division duplex in a wireless communication system

An apparatus for receiving signals in a base station of a CDMA communication system including a first and a second subordinate base station (Pico-BTS) having a small capacity, each including a transmission-reception antenna, a duplexer connected to the antenna, a transmitter for transmitting a signal through the duplexer to the antenna, a main receiver for receiving a signal from the antenna through the duplexer, and an auxiliary receiver, wherein the main receiver of each of the first and second Pico-BTS divides the signal from the antenna into two subordinate signals, one of which is applied to the main receiver in a normal way and the other is applied to the auxiliary receiver of another Pico-BTS.

Apparatus for receiving signals in a base station for cellular radio telecommunication system

An output control unit of a mobile communication system includes a transmit up-converter board having first and second mixers responsive to first and second oscillation frequency signals, respectively, for up-converting the frequency of a transmission signal, an attenuator installed between the transmit up-converter board and a final output terminal for controlling output of the up-converted transmission signal order to eliminate unwanted signal characteristic irrespective of amplification and attenuation when the transmission signal is up-converted for transmission and a transceiver slave control unit responsive to the second oscillation frequency signal for generating a control signal for controlling the attenuator, wherein the transceiver slave control unit utilizes an interface unit controlled to produce phase locked loop control data for controlling a local oscillator to generate the second local oscillation frequency of a designated channel, wherein the local oscillator informs the interface unit that it is locked at the designated channel's frequency; a main processor unit for detecting that the local oscillator is tuned to the designated channel in response to an output from the interface unit indicating that the local oscillator is locked at the designated channel's frequency; a control memory for storing a control voltage conversion table of digital-to-analog conversion step values, wherein the main processor unit searches for an output attenuation value of the designated channel in a channel conversion table and accesses the control version conversion table to determine a digital-to-analog conversion step value corresponding to the output attenuation value of the designated channel; and a digital-to-analog converter for converting the digital-to-analog conversion step value transmitted from the main processor unit into the control signal for controlling the attenuator.

Growing community of inventors

Suwon-si, South Korea

Cheol-Soo Seo