公开(公告)号：EP1665557A4

公开(公告)日：2013-06-05

申请号：EP04782302

申请日：2004-08-27

Applicant: GCT SEMICONDUCTOR INC

Inventor： JEON YOUNG-DEUK ,  LEE SEUNG-WOOK ,  LEE JEONG-WOO ,  PARK JOONBAE ,  LEE KYEONGHO

IPC: H04B1/38 ,  H01P1/213 ,  H03H11/12 ,  H03J1/00 ,  H04B1/10 ,  H04B1/44 ,  H04B1/48 ,  H04B1/52

CPC classification number: H04B1/1027 ,  H03H11/1252 ,  H03H11/1291 ,  H03J1/0008 ,  H04B1/44

Abstract: A system and method for filtering signals in a communications system reduces hardware and chip size requirements by selectively connecting a filter along transmitter and receiver paths of a transceiver. In operation, a controller generated signals for connecting the filter along the transmitter path when the transceiver is in transmitter mode and for connecting the filter along the receiver path when the transmitter is in receiver mode. The controller then generates additional signals for setting one or more parameters of the filter based on the path connected, or put differently based on the operational mode of the transceiver. In a variation, the controller sets the parameters of additional elements coupled to the filter as a way of further controlling processing of the transmitter and receiver signals. The system and method are particularly well suited to controlling the filtering of signals at the front-end of the transceiver having a direct-conversion architecture and in general ones performing time-multiplexing applications.

Abstract translation: 用于对通信系统中的信号进行滤波的系统和方法通过沿收发器的发射机和接收机路径选择性地连接滤波器来降低硬件和芯片尺寸的要求。 在操作中，当收发器处于发射机模式时，控制器产生用于沿着发射机路径连接滤波器的信号，并且当发射机处于接收机模式时，控制器沿接收机路径连接滤波器。 然后，控制器产生附加信号，用于基于连接的路径设置滤波器的一个或多个参数，或者基于收发器的操作模式进行不同的设置。 在一个变型中，控制器设置耦合到滤波器的附加元件的参数作为进一步控制发射机和接收机信号的处理的一种方式。 该系统和方法特别适用于控制在具有直接转换架构的收发器的前端处的信号的滤波，并且通常执行时间复用应用。

公开(公告)号：EP1716634A4

公开(公告)日：2013-04-10

申请号：EP05764681

申请日：2005-01-13

Applicant: GCT SEMICONDUCTOR INC

Inventor： LEE KANG YOON ,  KOO YIDO ,  LEE JEONG-WOO ,  PARK JOONBAE ,  LEE KYEONGHO

IPC: H03L7/085 ,  H03B5/00 ,  H03L7/099 ,  H03L7/197 ,  H03L7/199

CPC classification number: H03L7/085 ,  H03L7/099 ,  H03L7/1976 ,  H03L7/199

Abstract: An LC-VCO includes a multivibrator which outputs a frequency signal, a fine tuning circuit which tunes the frequency signal by a first amount, a coarse tuning circuit which tunes the frequency signal by a second amount, and a control circuit which controls the fine and coarse tuning circuits. The coarse tuning circuit is formed from one or more capacitive arrays and the fine tuning circuit is formed from one or more varactors. The capacitive arrays are preferably controlled by a digital signal, where each bit selectively couples a respective capacitor to the multivibrator. An analog signal controls the value of the varactors. The capacitive arrays and varactors charge and discharge an inducator in the multivibrator to tune the frequency signal. The VCO may be incorporated within a phase-locked loop, where the capacitors may be assigned different weight and/or redundancy values to tune an output frequency signal. In one embodiment, coarse tuning and lead-lag detection is performed more accurately to allow the size of the varactors to become significantly reduced compared with other circuits which have been proposed.

公开(公告)号：EP1374396A4

公开(公告)日：2007-12-12

申请号：EP02757825

申请日：2002-03-28

Applicant: GCT SEMICONDUCTOR INC

Inventor： JEONG HOE-SAM ,  LEE SEUNG-WOOK ,  LEE WON-SEOK ,  PARK JOONBAE ,  LEE KYEONGHO

IPC: H03F3/16 ,  H03G1/00 ,  H03G3/10 ,  H03G3/18

CPC classification number: H03F1/223 ,  H03F3/195 ,  H03F3/72 ,  H03F2200/294 ,  H03F2200/378 ,  H03F2200/391 ,  H03F2200/451 ,  H03F2203/7236 ,  H03G1/0088

Abstract: A variable gain, low noise amplifier is described, which is suitable as the input amplifier for a wireless terminal, or as the pre-amplifier stage of a wireless terminal transmitter. The amplifier (MN1) may achieve variable gain by deploying a network of transistors (MP1-MPn) in a parallel array, each independently selectable by a PMOS switch (220), and providing the variable resistance for the resonant circuit (Rp, Lp). Power dissipation can also be mitigated by using a network of driving transistors, each independently selectable by a PMOS switch (220). The resonant frequency of the amplifier may be made tunable by providing a selection of optional pull-up capacitors (Cp'1-Cp'n).

公开(公告)号：EP1374439A4

公开(公告)日：2007-04-18

申请号：EP02757777

申请日：2002-03-27

Applicant: GCT SEMICONDUCTOR INC

Inventor： KANG SUWON ,  LEE JEONG-WOO ,  PARK JOONBAE ,  LEE KYEONGHO

IPC: H03G3/20 ,  H03G3/30 ,  H04B1/30

CPC classification number: H03G3/3068

Abstract: A wireless or wired communication system and method is provided including a transmitter and a receiver. A RF communication system in accordance with the present invention includes an apparatus and gain control method between RF receiver (803) and baseband modem (804) in case of a plurality of gain stages (830, 846, 862) inside a receiver (803). The gain of each stage (830, 846, 862) can be controlled by an integrated gain controller (828). The gain controller (828) monitors the signal level of each gain stage (830, 846, 862) to place its gain to optimal value. The gain control apparatus and method can be implemented in a digital AGC system. The gain controller (828) accepts a signal (826) implementing gain control and thus there is no stability issue. When distributed gain stages are present inside a related art receiver and separate gain control loops are used, stability issues can arise.

公开(公告)号：EP1557019A4

公开(公告)日：2006-06-07

申请号：EP03779213

申请日：2003-10-23

Applicant: GCT SEMICONDUCTOR INC

Inventor： PARK JOONBAE ,  LEE KYEONGHO ,  SONG EUNSEOK ,  JUNG YEONJAE

IPC: H04B1/10 ,  H04L25/10

CPC classification number: H04B1/109

Abstract: A communications receiver includes a baseband signal recovery circuit which uses a low-IF architecture for data reception. The baseband signal recovery circuit uses a full-analog implementation for channel selection and filtering. Thus, the overhead placed on the design of analog-to-digital converter is greatly relaxed and most of hardware can be re-used for multi-mode applications with only a slight modification.

公开(公告)号：EP1433250A4

公开(公告)日：2004-12-29

申请号：EP02759481

申请日：2002-08-29

Applicant: GCT SEMICONDUCTOR INC

Inventor： JEONG HEI-SAM ,  PARK JOONBAE ,  LEE KYEONGHO

IPC: H03F1/32 ,  H03F1/34 ,  H03F3/68

CPC classification number: H03F1/3223 ,  H03F1/3229

Abstract: The present invention is directed to a linearization apparatus and method. Preferred embodiments according to the present invention can combine an auxiliary non-linear block (300) to a functional block of a system to increase linearity of an output signal (520) of the system such as a communication system. System overhead due to the non-linear auxiliary block can be small because of circuit structure, cost and low consumption. Further, the non-linear auxiliary block can be designed so that no feedback path is required. Further preferred embodiments can use a feedback path without loss of stability by using a cancellation apparatus or process based on an averaging detection of the output signal. For example, a feedback loop can detect power leakage in a sideband caused by non-linearities of the communication system.