John Zhang

US Patent:

6466088, Oct 15, 2002

Filed:

Feb 7, 2001

Appl. No.:

09/779254

Inventors:

Behrooz Rezvani - Pleasanton CA
John Zhongxuan Zhang - Fremont CA
Dale Smith - Fremont CA
Caesar Seehoi Wong - Fremont CA

Assignee:

Ikanos Communications - Fremont CA

International Classification:

H03F 114

US Classification:

330 51, 330124 R, 330136

Abstract:

An apparatus and method for reducing power requirements in X-DSL and other communication protocols is disclosed. The apparatus may be applied with equal advantage in wired and wireless media Power is supplied selectively to input lines in which input signals exceed selected threshold levels. The apparatus is configured to support statistical multiplexing of the input signal lines across a plurality of amplification means which support amplification at up to either of at least two power levels. This reduces overall power requirements for the combined input lines. In an embodiment of the invention an apparatus for providing amplification of input signals on corresponding ones of a plurality of input signal lines is disclosed. The apparatus includes primary amplifiers and at least one secondary amplifier with higher output levels than the primary amplifier which can be statistical multiplexed to whichever of the input signal lines requires additional amplification. In an alternate embodiment of the invention each input signal line is coupled to a corresponding amplifier which can be statistically multiplexed to a power supplies of varying output levels depending on the amplification requirements of each of the input signal lines.

US Patent:

6501405, Dec 31, 2002

Filed:

Jun 13, 2001

Appl. No.:

09/881857

Inventors:

John Zhongxuan Zhang - Fremont CA
Peter Gunadisastra - Palo Alto CA
Dale Smith - Fremont CA
Mong Yang - San Jose CA
Ali Al-Shamma - San Jose CA

Assignee:

IKANOS Communication, Inc. - Fremont CA

International Classification:

H03M 300

US Classification:

341143, 341118, 341120, 341144, 341155

Abstract:

An apparatus and method is disclosed for minimizing in band distortion in the transmit path of an XDSL modem. The transmit path of an XDSL modem introduces various non-linearities into transmissions in both the frequency and time domains. The current invention provides a means for both determining and correcting for distortion in the time domain. In an embodiment of the invention the apparatus may include a calibrator which may be implemented using the existing analog-to-digital (ADC) conversion and demodulation capabilities on the receive path of the modem or alternately, a dedicated module. During a calibration phase a training signal is injected digitally into the digital-to-analog converter of the transmit path. The analog portion of the transmit path is coupled to a calibrator which measures the corresponding analog response. The correlation between input and response is stored in an analog model.

US Patent:

6582392, Jun 24, 2003

Filed:

Aug 16, 1999

Appl. No.:

09/375162

Inventors:

Frederick J. Bennett - Issaquah WA
John Zhang - Bothell WA
Gary Lichttenegger - Woodinville WA
James E. Rodriguey - Seattle WA
Katsuro Tachibana - Fukuoka, JP

Assignee:

Ekos Corporation - Bothell WA

International Classification:

A61B 1720

US Classification:

604 22, 601 2

Abstract:

The invention relates to a catheter system. The system comprises a catheter body having a chamber containing a low acoustic impedance medium. The catheter body includes an elongated body with an external surface and an ultrasound transducer having an external side between a first end and a second end. The ultrasound transducer is positioned over the external surface of the elongated body such that the first end is adjacent to the chamber.

US Patent:

6687079, Feb 3, 2004

Filed:

Oct 8, 1999

Appl. No.:

09/415147

Inventors:

John Xiao Zhang - Cupertino CA

Assignee:

Samsung Electronics Co., LTD

International Classification:

G11B 5596

US Classification:

360 7708, 360 29, 360 39

Abstract:

A method and apparatus for generating a position information signal for the head of a hard disk drive. The disk has a track which contains a plurality of servo bursts that allow the head to be centered with the centerline of the track. The servo bursts are first sensed and an upper and a lower threshold values, based on the values of servo bursts, are generated. A position error signal based on the upper and lower threshold and the values of the servo bursts are generated and stored in a memory device.

US Patent:

6698538, Mar 2, 2004

Filed:

May 1, 2002

Appl. No.:

10/136459

Inventors:

Steffen S. Kristiansen - Stavanger, NO
Michael G. Azar - The Woodlands TX
John Zhang - Tomball TX

Assignee:

Smith International, Inc. - Houston TX

International Classification:

E21B 1060

US Classification:

175340, 175393, 175 57

Abstract:

A drill bit is disclosed which includes a bit body having a plurality of ports therein arranged to provide a flow path between an interior of a drill string and the exterior of the bit body. At least one flow relief is disposed in one of the ports. The at least one flow relief is adapted to provide an increase in total flow area of the bit upon application to the bit of a selected fluid flow condition. A method for changing a total flow area of a drill bit is also disclosed, which includes pumping drilling fluid through the drill bit and operating a flow relief disposed in the bit to change the total flow area of the bit.

US Patent:

6723063, Apr 20, 2004

Filed:

Jun 29, 1998

Appl. No.:

09/107078

Inventors:

John Zhang - Bothell WA
Gary Lichttenegger - Woodinville WA
James E. Rodriguey - Seattle WA
Katsuro Tachibana - Fukuoka, JP

Assignee:

Ekos Corporation - Bothell WA

International Classification:

A61B 1720

US Classification:

604 22

Abstract:

A system for delivering ultrasound energy to a treatment section in a vessel is disclosed. The system includes a sheath with a utility lumen and an energy delivery section at least partially constructed from a material which transmits ultrasound energy. The system also includes a drug delivery member having a plurality of drug delivery ports which are positioned adjacent the energy delivery section. The system further includes an elongated body including at least one ultrasound element and configured to be movably positioned within the utility lumen to transmit the ultrasound energy from the ultrasound element through the energy delivery section.

US Patent:

6873653, Mar 29, 2005

Filed:

Feb 7, 2001

Appl. No.:

09/779256

Inventors:

Behrooz Rezvani - Pleasanton CA, US
Sam Heidari - Fremont CA, US
John Zhongxuan Zhang - Fremont CA, US
Dale Smith - Fremont CA, US

Assignee:

Ikanos Communication, Inc. - Fremont CA

International Classification:

H04L005/16

US Classification:

375222, 375219

Abstract:

An apparatus and method is provided for minimizing in channel distortion in an X-DSL line driver is disclosed. The apparatus may be incorporated in an existing X-DSL architecture without additional circuitry. Out of band monitoring of a channel is implemented to adaptively minimize out of band interference and in band distortion. A unique training sequence, suitable for DMT line codes is set forth. The training sequence allows a full spectral characterization of the downstream signal space with a single upstream monitoring tone. The invention may be used with multi-channel X-DSL line drivers interfacing with any of a number of multi-channel supply architectures. The apparatus may be applied with equal advantage to communication protocols other than X-DSL. The apparatus may be applied with equal advantage in wired and wireless media.

US Patent:

6987915, Jan 17, 2006

Filed:

Mar 18, 2004

Appl. No.:

10/803804

Inventors:

Stephen P. Merrick - San Jose CA, US
Lynn Wiese - Santa Clara CA, US
Kalberer Martin - Redwood City CA, US
John Zhang - Santa Clara CA, US

International Classification:

G02B 6/26

US Classification:

385 52, 385 33, 385147, 356123, 356609

Abstract:

An embodiment described herein provides a technique to determine a focus point of a lense. Light is directed from a light source through the lense and onto a target surface. The light source and target surface may be positioned on opposite sides of the lense. The target surface may correspond to the position of where a primary light source for the particular application is to be located. A reflection passing through the lense from the reflective target surface may be located. A determination is then made as to whether the position where the reflection was located also could also corresponds to a focus point for the lense, if the primary light source was to be located at or near the target surface.