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公开(公告)号：CA2555468C
公开(公告)日：2016-05-03
申请号：CA2555468
申请日：2005-01-13
Applicant: GCT SEMICONDUCTOR INC
Inventor： LEE KANG YOON , KOO YIDO , LEE JEONG-WOO , PARK JOONBAE , LEE KYEONGHO
Abstract: Tuning methods and apparatuses for LC oscillators are disclosed. Embodiments of the present invention include an adaptively controlling the bit~comparison time to provide the smallest coarse tuning time. The bit comparison time is scaled inversely to the amount of redundancy of corresponding weighted capacitors in a capacitor array of the LC oscillator.
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公开(公告)号：CA2582345C
公开(公告)日：2013-11-05
申请号：CA2582345
申请日：2005-09-21
Applicant: GCT SEMICONDUCTOR INC
Inventor： KOO YIDO , AHN YOUNGHO , SONG EUNSEOK , LEE JEONG-WOO , PARK JOONBAE , LEE KYEONGHO
IPC: H03D3/24
Abstract: A sigma-delta based phase lock loop device is provided that includes a phase frequency detector (PFD), a charge pump and a voltage controlled oscillator. The PDF to receive a reference signal and a feedback signal and to output signals based on a comparison of the reference signal and the feedback signal. The charge pump to output a charge based on the output signals from the PFD. The charge pump including a first current source to apply a fixed amount of current and a second current source to apply a variable amount of current. The voltage controlled oscillator to output a clock signal based on the received charge from the charge pump.
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公开(公告)号：DE60234580D1
公开(公告)日：2010-01-14
申请号：DE60234580
申请日：2002-03-27
Applicant: GCT SEMICONDUCTOR INC
Inventor： KANG SUWON , LEE JEONG-WOO , PARK JOONBAE , LEE KYEONGHO
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 and baseband modem in case of a plurality of gain stages inside a receiver. The gain of each stage can be controlled by an integrated gain controller. The gain controller monitors the signal level of each gain stage to place its gain to optimal value. The gain control apparatus and method can be implemented in a digital AGC system. The gain controller accepts a signal 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. In a preferred embodiment of an apparatus and method, the baseband modem decides the amount of gain control and adjusts the gain of certain gain stages by the proper amount.
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公开(公告)号：HK1082351A1
公开(公告)日：2006-06-02
申请号：HK06104363
申请日：2006-04-11
Applicant: GCT SEMICONDUCTOR INC
Inventor： LEE KANG-YOON , SONG EUNSEOK , LEE JEONG-WOO , PARK JOONBAE , LEE KYEONGHO
IPC: H03C3/09 , H04L20100101
Abstract: A translational-loop transmitter generates RF signals using at most one phase-locked-loop (PLL) circuit. In one embodiment, a single PLL generates two local oscillation signals. The first oscillation signal is mixed with a baseband signal to generate an intermediate frequency signal. The second oscillation signal is input into the translational loop to adjust a voltage-controlled oscillator to the desired carrier frequency. In order to perform this type of modulation, the frequencies of the local oscillation signals are set so that they are harmonically related to one another relative to the carrier frequency. Other embodiments generate only one oscillation signal. Under these conditions, the intermediate frequency signal is generated using the oscillation signal, and a frequency divider in the translational loop is used to generate a control signal for adjusting the voltage-controlled oscillator to the carrier frequency. In still other embodiments, a transmitter signal is generated without using any phase-locked-loop circuits. This is accomplished by generating an intermediate frequency signal using a crystal oscillator, and then using a frequency divider in a feedback loop to generate a control signal for adjusting the voltage-controlled oscillator to the carrier frequency. By minimizing the number of phase-locked-loop circuits in the transmitter, the size, cost, and power requirements of mobile handsets may be significantly reduced.
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公开(公告)号：AU2003284892A1
公开(公告)日：2004-05-25
申请号：AU2003284892
申请日：2003-10-23
Applicant: GCT SEMICONDUCTOR INC
Inventor： PARK JOONBAE , LEE KYEONGHO , SONG EUNSEOK , JUNG YEONJAE
IPC: H04B1/10
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.
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Patent Agency Ranking
公开(公告)号：CA2442515A1
公开(公告)日：2002-10-10
申请号：CA2442515
申请日：2002-03-27
Applicant: GCT SEMICONDUCTOR INC
Inventor： LEE JEONG-WOO , PARK JOONBAE , KANG SUWON , LEE KYEONGHO
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.
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公开(公告)号：CA2442332A1
公开(公告)日：2002-10-10
申请号：CA2442332
申请日：2002-03-28
Applicant: GCT SEMICONDUCTOR INC
Inventor： JEONG HOE-SAM , LEE WON-SEOK , LEE SEUNG-WOOK , PARK JOONBAE , LEE KYEONGHO
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).
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公开(公告)号：CA2458877C
公开(公告)日：2011-01-25
申请号：CA2458877
申请日：2002-08-29
Applicant: GCT SEMICONDUCTOR INC
Inventor： JEONG HEI-SAM , PARK JOONBAE , LEE KYEONGHO
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.
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公开(公告)号：HK1095677A1
公开(公告)日：2007-05-11
申请号：HK07102851
申请日：2007-03-16
Applicant: GCT SEMICONDUCTOR INC
Inventor： JEON YOUNG-DEUK , LEE SEUNG-WOOK , LEE JEONG-WOO , PARK JOONBAE , LEE KYEONGHO
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.
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公开(公告)号：CA2580945A1
公开(公告)日：2006-04-06
申请号：CA2580945
申请日：2005-09-21
Applicant: GCT SEMICONDUCTOR INC
Inventor： PARK JOONBAE , LEE KYEONGHO , LEE SEUNG-WOOK , LEE JEONG-WOO
IPC: H03L7/08
Abstract: An apparatus for oscillating a frequency, which comprises a phase lock loop, see fig. 5, a variable frequency divider() is shown, that divides a first frequency (Fout) signal by a division ratio to generate a second frequency signal, this based on a comparison of reference frequency clock input (Fref) and feedback input to phase/frequency detector (510). A charge pump (520) and loop filter (530) are shown with a divider (550) that divides the second frequency signal (355) to allow the correct feedback frequency to be realized. The VCO (540) inherently has a resonant circuit including the capacitors to be selected and a corresponding control voltage to set the frequency of operation as well as an active circuit (320) for proper gain.
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