Patents by Inventor Hea Joung Kim
Hea Joung Kim has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7454189Abstract: Calibration of received signal strength indication (RSSI) within a radio frequency integrated circuit (RFIC) begins by concurrently enables a transmitter portion and receiver portion. With both the transmitter and receiver enabled, the RFIC provides a zero input to the transmitter portion, where the zero input is an effective zero input based on the input circuitry of the transmitter portion. The RFIC then measures, via the receiver portion, the received signal strength of the RF signal generated by the transmitter portion regarding the zero input signal. The RFIC then compares the measured received signal strength with a desired zero input signal strength value. If the measured received signal strength compares unfavorably with the desired zero input signal strength value (e.g.Type: GrantFiled: October 26, 2004Date of Patent: November 18, 2008Assignee: Broadcom CorporationInventor: Hea Joung Kim
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Publication number: 20080214112Abstract: In RF transceivers, a method and system for using phase shift key (PSK) sync word for fine tuning frequency adjustment are provided. One aspect of the invention provides for adjusting a local oscillator frequency in a radio frequency (RF) receiver when a residual DC offset remains after a coarse frequency offset adjustment if performed. The fine adjustment may be necessary because of the synchronization required with a PSK-based modulated portion of a Bluetooth packet. A residual phase shift detected in a sync sequence portion of the Bluetooth packet may be utilized to determine a residual or fine frequency adjustment. This approach may allow an RF receiver to operate, in some instances, without the need for an equalizer. In this regard, the power consumed by the RF receiver may be minimized and/or the overall cost of the RF receiver may be reduced.Type: ApplicationFiled: March 20, 2008Publication date: September 4, 2008Inventors: Brima Ibrahim, Hea Joung Kim, Henrik Tholstrup Jensen, Siukai Mak
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Patent number: 7415246Abstract: A method for determining attenuation of a transmit/receive switch for attenuating inbound RF signals begins by enabling the transmit/receive switch to provide a loop back configuration between a transmitter section and a receiver section of a radio frequency integrated circuit. When the transmit section provides a test RF signal to the receiver section the processing continues when the receiver section measures the signal strength of the test RF signal to produce a 1st signal strength. The processing continues by enabling receive attenuation mode of the transmit/receive switch. The processing continues when the transmit section provides another test RF signal to the receiver section via the transmit/receive switch in the receive attenuation mode to produce an attenuated test RF signal. The processing continues when the receive section measures the signal strength of the attenuated test RF signal to produce a 2nd signal strength.Type: GrantFiled: November 5, 2003Date of Patent: August 19, 2008Assignee: Broadcom CorporationInventors: Hea Joung Kim, Brima B. Ibrahim
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Patent number: 7398452Abstract: Certain aspects of determining a signal quality metric in event of a CRC false positive may comprise measuring an amplitude and/or phase of at least a portion of a phase shift keyed section of a frame. The measured amplitude and/or phase may be checked to determine if it lies within a range of a reference amplitude and/or phase respectively. An amplitude and/or phase counter may be incremented if the measured amplitude and/or phase lies outside the range of the reference amplitude and/or phase respectively. A confidence level value of a cyclic redundancy check (CRC) for at least a portion of the phase shift keyed section of the frame may be determined based on a determined value of the incremented amplitude and/or phase counter.Type: GrantFiled: March 30, 2005Date of Patent: July 8, 2008Assignee: Broadcom CorporationInventors: Hea Joung Kim, Paul Anthony Lettieri, Brima Ibrahim, Siukai Mak
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Patent number: 7375595Abstract: Methods and apparatus for calibrating a transitional loop, such as a phase locked loop, are disclosed. An example method includes performing an open loop calibration of a voltage controlled oscillator (VCO). The open loop calibration includes tuning the output oscillation frequency of the VCO to within a predetermined range of frequencies. The example method further includes determining a voltage offset and a gain error of an analog to digital converter (ADC) coupled with the phase locked loop. The example method also includes determining a gain offset of the open loop calibrated VCO using the voltage offset and the gain error of the ADC. In the example method, a signal provided by a charge pump of the PLL is adjusted based on the determined gain offset.Type: GrantFiled: September 29, 2006Date of Patent: May 20, 2008Assignee: Broadcom CorporationInventors: Louie Serrano, Alireza Zolfaghari, Paul Lettieri, Hea Joung Kim, Hooman Darabi, Henrik Jensen, Behnam Mohammadi
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Publication number: 20080079509Abstract: Methods and apparatus for calibrating a transitional loop, such as a phase locked loop, are disclosed. An example method includes performing an open loop calibration of a voltage controlled oscillator (VCO). The open loop calibration includes tuning the output oscillation frequency of the VCO to within a predetermined range of frequencies. The example method further includes determining a voltage offset and a gain error of an analog to digital converter (ADC) coupled with the phase locked loop. The example method also includes determining a gain offset of the open loop calibrated VCO using the voltage offset and the gain error of the ADC. In the example method, a signal provided by a charge pump of the PLL is adjusted based on the determined gain offset.Type: ApplicationFiled: September 29, 2006Publication date: April 3, 2008Inventors: Louie Serrano, Alireza Zolfaghari, Paul Lettieri, Hea Joung Kim, Hooman Darabi, Henrik Jensen, Behnam Mohammadi
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Patent number: 7349680Abstract: In RF transceivers, a method and system for using phase shift key (PSK) sync word for fine tuning frequency adjustment are provided. One aspect of the invention provides for adjusting a local oscillator frequency in a radio frequency (RF) receiver when a residual DC offset remains after a coarse frequency offset adjustment if performed. The fine adjustment may be necessary because of the synchronization required with a PSK-based modulated portion of a Bluetooth packet. A residual phase shift detected in a sync sequence portion of the Bluetooth packet may be utilized to determine a residual or fine frequency adjustment. This approach may allow an RF receiver to operate, in some instances, without the need for an equalizer. In this regard, the power consumed by the RF receiver may be minimized and/or the overall cost of the RF receiver may be reduced.Type: GrantFiled: April 8, 2005Date of Patent: March 25, 2008Assignee: Broadcom CorporationInventors: Brima Ibrahim, Hea Joung Kim, Henrik Tholstrup Jensen, Siukai Mak
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Patent number: 7345490Abstract: A method for calibrating a filter begins with the filter filtering a first signal having a first frequency to produce a first filtered signal, wherein the first frequency is in a known pass region of the filter. The processing continues by measuring signal strength of the first filtered signal to produce a first measured signal strength. The processing continues with the filter filtering a second signal having a second frequency to produce a second filtered signal, wherein the second frequency is at a desired corner frequency of the filter. The processing continues by measuring signal strength of the second filtered signal to produce a second measured signal strength. The processing continues by comparing the first measured signal strength with the second measured signal strength to determine whether the filter has attenuated the second signal by a desired attenuation value with respect to the first signal.Type: GrantFiled: May 3, 2005Date of Patent: March 18, 2008Assignee: Broadcom CorporationInventors: Brima B. Ibrahim, Hea Joung Kim
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Publication number: 20080026787Abstract: Aspects of a method and system for a mobile piconet base station are provided. Switching and/or routing capabilities in mobile handset may enable wireless devices to communicate with each other and/or with a wireless network via the mobile handset. The mobile handset operates as a base station for wireless devices within a personal area or piconet. For voice communication, for example, communication between a wireless device within the piconet and a cellular network or a voice-over-IP (VoIP) network may be established via the mobile handset. The selection between the cellular or VoIP network may be based on rate price and/or on features available in each of the networks, for example. Communication between the wireless devices and the base station mobile handset may occur via a Bluetooth connection and/or another type of wireless technology, for example. The wireless devices may be low-cost, small form factor mobile handsets, for example.Type: ApplicationFiled: July 26, 2006Publication date: January 31, 2008Inventors: Brima Ibrahim, Hea Joung Kim
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Patent number: 7127222Abstract: A method for adjusting automatic gain control of a radio receiver begins by determining power level of a radio frequency (RF) signal received by the radio receiver to produce a determined power level. The method then continues by comparing the determined power level with a plurality of power thresholds to determine whether an automatic gain adjustment is needed. The method then continues, when the automatic gain adjustment is needed, by determining, from the comparing the determined power level with the plurality of power thresholds, a sign of the automatic gain adjustment. The method continues by determining, from the comparing the determined power level with the plurality of power thresholds, a magnitude of the automatic gain adjustment. The method continues by addressing a gain adjustment look up table for at least a portion of the radio receiver based on the magnitude to produce a gain setting.Type: GrantFiled: June 28, 2004Date of Patent: October 24, 2006Assignee: Broadcom CorporationInventors: Hea Joung Kim, Paul Anthony Lettieri, Brima B. Ibrahim
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Patent number: 7095992Abstract: A method for calibrating a phase locked loop (PLL) includes an open loop test and a closed loop test. The open loop test includes providing an optimal control input to a controlled oscillator (CO) of the PLL; determining rate of output oscillation of the CO based on the optimal control input; comparing the rate of the output oscillation with rate of an optimal output oscillation; and when the comparing the rate of the output oscillation with rate of the optimal output oscillation is unfavorable, adjusting an oscillation point of the CO until the comparing is favorable to produce an open-loop adjusted CO oscillation point.Type: GrantFiled: December 19, 2003Date of Patent: August 22, 2006Assignee: Broadcom CorporationInventors: Hea Joung Kim, Brima B. Ibrahim
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Publication number: 20060077010Abstract: A method for calibrating a phase locked loop begins by determining a gain offset of a voltage controlled oscillator of the phase locked loop. The processing then continues by adjusting current of a charge pump of the phase locked loop based on the gain offset.Type: ApplicationFiled: November 16, 2005Publication date: April 13, 2006Inventors: Henrik T. Jensen, Hea Joung Kim
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Patent number: 6999744Abstract: The measuring of local oscillation leakage in radio frequency integrated circuits (RFICs) begins by concurrently enabling a transmitter portion and a receiver portion of a radio frequency integrated circuit. The processing then continues by providing a zero input to the transmitter portion such that information contained in the RF signals corresponds to local oscillation leakage produced by the transmitter portion. The processing continues by detecting the concurrent enablement of the transmitter and receiver portions. The processing continues by measuring, via the receiver portion, the received signal strength of the RF signals. The processing continues by processing the received signal strength over a predetermined period of time commencing upon the detection of the concurrent enablement to obtain a measure of the local oscillation leakage.Type: GrantFiled: September 26, 2002Date of Patent: February 14, 2006Assignee: Broadcom CorpInventor: Hea Joung Kim
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Patent number: 6998922Abstract: A method for calibrating a phase locked loop begins by determining a gain offset of a voltage controlled oscillator of the phase locked loop. The processing then continues by adjusting current of a charge pump of the phase locked loop based on the gain offset.Type: GrantFiled: September 8, 2003Date of Patent: February 14, 2006Assignee: Broadcom Corp.Inventors: Henrik T. Jensen, Hea Joung Kim
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Patent number: 6914437Abstract: A method for calibrating a filter begins with the filter filtering a first signal having a first frequency to produce a first filtered signal, wherein the first frequency is in a known pass region of the filter. The processing continues by measuring signal strength of the first filtered signal to produce a first measured signal strength. The processing continues with the filter filtering a second signal having a second frequency to produce a second filtered signal, wherein the second frequency is at a desired corner frequency of the filter. The processing continues by measuring signal strength of the second filtered signal to produce a second measured signal strength. The processing continues by comparing the first measured signal strength with the second measured signal strength to determine whether the filter has attenuated the second signal by a desired attenuation value with respect to the first signal.Type: GrantFiled: August 21, 2003Date of Patent: July 5, 2005Assignee: Broadcom Corp.Inventors: Brima B. Ibrahim, Hea Joung Kim
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Publication number: 20050052251Abstract: A method for calibrating a phase locked loop begins by determining a gain offset of a voltage controlled oscillator of the phase locked loop. The processing then continues by adjusting current of a charge pump of the phase locked loop based on the gain offset.Type: ApplicationFiled: September 8, 2003Publication date: March 10, 2005Inventors: Henrik Jensen, Hea Joung Kim
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Patent number: 6829550Abstract: Calibration of received signal strength indication (RSSI) within a radio frequency integrated circuit (RFIC) begins by concurrently enables a transmitter portion and receiver portion. With both the transmitter and receiver enabled, the RFIC provides a zero input to the transmitter portion, where the zero input is an effective zero input based on the input circuitry of the transmitter portion. The RFIC then measures, via the receiver portion, the received signal strength of the RF signal generated by the transmitter portion regarding the zero input signal. The RFIC then compares the measured received signal strength with a desired zero input signal strength value. If the measured received signal strength compares unfavorably with the desired zero input signal strength value (e.g.Type: GrantFiled: September 26, 2002Date of Patent: December 7, 2004Assignee: Broadcom Corp.Inventor: Hea Joung Kim
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Publication number: 20040242174Abstract: A method for adjusting automatic gain control of a radio receiver begins by determining power level of a radio frequency (RF) signal received by the radio receiver to produce a determined power level. The method then continues by comparing the determined power level with a plurality of power thresholds to determine whether an automatic gain adjustment is needed. The method then continues, when the automatic gain adjustment is needed, by determining, from the comparing the determined power level with the plurality of power thresholds, a sign of the automatic gain adjustment. The method continues by determining, from the comparing the determined power level with the plurality of power thresholds, a magnitude of the automatic gain adjustment. The method continues by addressing a gain adjustment look up table for at least a portion of the radio receiver based on the magnitude to produce a gain setting.Type: ApplicationFiled: June 28, 2004Publication date: December 2, 2004Inventors: Hea Joung Kim, Paul Anthony Lettieri, Brima B. Ibrahim
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Publication number: 20040203548Abstract: The measuring of local oscillation leakage in radio frequency integrated circuits (RFICs) begins by concurrently enabling a transmitter portion and a receiver portion of a radio frequency integrated circuit. The processing then continues by providing a zero input to the transmitter portion such that information contained in the RF signals corresponds to local oscillation leakage produced by the transmitter portion. The processing continues by detecting the concurrent enablement of the transmitter and receiver portions. The processing continues by measuring, via the receiver portion, the received signal strength of the RF signals. The processing continues by processing the received signal strength over a predetermined period of time commencing upon the detection of the concurrent enablement to obtain a measure of the local oscillation leakage.Type: ApplicationFiled: September 26, 2002Publication date: October 14, 2004Inventor: Hea Joung Kim
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Publication number: 20040063412Abstract: Attenuation of received RF signals begins by determining signal strength of the received signal. The processing continues by determining whether the signal strength of the received signal exceeds a high power threshold. The high power threshold is set just below a power level at which the receiver would saturate (e.g., clip the received signals). Processing continues by enabling transmit mode of a transmit/receive switch while receiving the RF signal when the signal strength of the received signal exceeds the high power threshold. With the transmit/receive switch in the transmit mode while receiving an RF signal, the transmit/receive switch provides an attenuation of approximately 20 dBm.Type: ApplicationFiled: September 26, 2002Publication date: April 1, 2004Inventors: Hea Joung Kim, Brima Ibrahim, Ahmadreza (Reza) Rofougaran