Hea J Kim

US Patent:

6914437, Jul 5, 2005

Filed:

Aug 21, 2003

Appl. No.:

10/645130

Inventors:

Brima B. Ibrahim - Aliso Viejo CA, US
Hea Joung Kim - Los Angeles CA, US

Assignee:

Broadcom Corp. - Irvine CA

International Classification:

G01R027/28

US Classification:

324616, 455340

Abstract:

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. The processing continues by adjusting filter response of the filter to produce an adjusted filter response when the filter has not attenuated the second signal by the desired attenuation value with respect to the first signal.

US Patent:

6998922, Feb 14, 2006

Filed:

Sep 8, 2003

Appl. No.:

10/657434

Inventors:

Henrik T. Jensen - Long Beach CA, US
Hea Joung Kim - Los Angeles CA, US

Assignee:

Broadcom Corp. - Irvine CA

International Classification:

H03L 7/08
H03L 7/099

US Classification:

331 17, 331 14, 331 16, 331 18, 331 25

Abstract:

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.

US Patent:

7095992, Aug 22, 2006

Filed:

Dec 19, 2003

Appl. No.:

10/742489

Inventors:

Hea Joung Kim - Los Angeles CA, US
Brima B. Ibrahim - Aliso Viejo CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/18
H04B 17/00
H04B 1/40

US Classification:

4551803, 455260, 4552261, 455 6711, 455 76

Abstract:

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. The close loop test includes determining a closed-loop input control level of the CO at the open-loop adjusted CO oscillation point; comparing the closed-loop input control level with the optimal control input; and when the comparing the closed-loop input control level with the optimal control input is not favorable, adjusting the open-loop adjusted CO oscillation point until the comparing is favorable.

US Patent:

7127222, Oct 24, 2006

Filed:

Jun 28, 2004

Appl. No.:

10/879244

Inventors:

Hea Joung Kim - Los Angeles CA, US
Paul Anthony Lettieri - Lake Forest CA, US
Brima B. Ibrahim - Aliso Viejo CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/16

US Classification:

4552321, 4552342, 375345

Abstract:

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. The method then continues by adjusting the automatic gain of the radio receiver based on the sign of the automatic gain adjustment and the gain setting.

US Patent:

7345490, Mar 18, 2008

Filed:

May 3, 2005

Appl. No.:

11/120608

Inventors:

Brima B. Ibrahim - Aliso Viejo CA, US
Hea Joung Kim - Los Angeles CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

G01R 27/28
H04B 15/00

US Classification:

324616, 702190

Abstract:

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. The processing continues by adjusting filter response of the filter to produce an adjusted filter response when the filter has not attenuated the second signal by the desired attenuation value with respect to the first signal.

US Patent:

7349680, Mar 25, 2008

Filed:

Apr 8, 2005

Appl. No.:

11/101961

Inventors:

Brima Ibrahim - Aliso Viejo CA, US
Hea Joung Kim - Irvine CA, US
Henrik Tholstrup Jensen - Long Beach CA, US
Siukai Mak - Poway CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H04B 1/26

US Classification:

455260, 455318, 375319

Abstract:

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.

US Patent:

7375595, May 20, 2008

Filed:

Sep 29, 2006

Appl. No.:

11/540878

Inventors:

Louie Serrano - Irvine CA, US
Alireza Zolfaghari - Irvine CA, US
Paul Lettieri - Lake Forest CA, US
Hea Joung Kim - Irvine CA, US
Hooman Darabi - Irvine CA, US
Henrik Jensen - Long Beach CA, US
Behnam Mohammadi - Aliso Viejo CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H03L 7/08
H03L 7/099

US Classification:

331 44, 331 16, 331 17

Abstract:

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.

US Patent:

7398452, Jul 8, 2008

Filed:

Mar 30, 2005

Appl. No.:

11/093388

Inventors:

Hea Joung Kim - Irvine CA, US
Paul Anthony Lettieri - Lake Forest CA, US
Brima Ibrahim - Aliso Viejo CA, US
Siukai Mak - Poway CA, US

Assignee:

Broadcom Corporation - Irvine CA

International Classification:

H03M 13/00

US Classification:

714776, 714774, 714758, 375340

Abstract:

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.