David Oi Yu

US Patent:

20040061456, Apr 1, 2004

Filed:

Sep 30, 2002

Appl. No.:

10/261831

Inventors:

David Yu - Rancho Palos Verdes CA, US
James Clendenin - Menlo Park CA, US
Robert Kirby - Cupertino CA, US

International Classification:

H05H009/00

US Classification:

315/505000

Abstract:

A photoelectron linear accelerator for producing a low emittance polarized electron beam. The linear accelerator includes a tube having an inner wall, the inner tube wall being coated by a getter material. A portable, or demountable, cathode plug is mounted within said tube, the surface of said cathode having a semiconductor material formed thereon.

US Patent:

20070047601, Mar 1, 2007

Filed:

Aug 9, 2005

Appl. No.:

11/199628

Inventors:

David Yu - Rancho Palos Verdes CA, US

International Classification:

H01S 3/10
H01S 3/08

US Classification:

372025000, 372100000, 372103000

Abstract:

A device for generating a plurality of laser pulses from a recirculating single laser pulse in an optical delay line that is capable of partially transmitting the trapped pulse out of the delay line. The energy of the partially reflected trapped pulse is restored before beginning another round trip in the delay line. The time structure of an output pulse train thus generated by the device comprises a sequence of macro pulses, each comprising a plurality of micro pulses.

US Patent:

20090146085, Jun 11, 2009

Filed:

Dec 7, 2007

Appl. No.:

11/999754

Inventors:

Alexei V. Smirnov - Rancho Palos Verdes CA, US
David U.L. Yu - Rancho Palos Verdes CA, US

International Classification:

G02F 1/39

US Classification:

250504 R

Abstract:

A sub-mm wave source based on Cherenkov resonant radiation of a microbunched electron beam radiating coherently in a dielectric-loaded pipe. The microbunched electron beam is produced in a pulse photoinjector by illuminating a metal photocathode with sub-ps or multi-ps intensity-modulated laser beam with a beat wave or multiplexing at terahertz frequencies, the photoelectrons generated at the photocathode being accelerated by an electric field and sub-wavelength focused by magnetic field to propagate through a resonant radiator comprising a corrugated wall or smooth-wall metal capillary pipe internally coated with dielectric and attached to an antenna.

US Patent:

20100030599, Feb 4, 2010

Filed:

Aug 4, 2008

Appl. No.:

12/185178

Inventors:

Anh Q. Lu - Austin TX, US
Gautham Pamu - Round Rock TX, US
David Y. Yu - Austin TX, US

International Classification:

G06Q 10/00
G06Q 20/00

US Classification:

705 7, 705 35

Abstract:

A method, system, and computer program product for integrating Health Care Payers and Providers with a health care transaction system. The health care transaction (HCT) utility solves the problem of integration between these two parties by providing the developer with an application that is capable of automatically generating an Electronic Data Interchange (EDI) response message to a request. The HCT utility mainly consists of a servlet (associated with the Hypertext Transfer Protocol (HTTP) or other data communication protocol) that forwards an EDI request from a sending party to applications that may act as either a payer or provider. These applications may automatically process and respond to request EDI messages sent from other applications using an EDI processor application. The HCT utility provides the advantage of providing an infrastructure for testing healthcare transactions. Furthermore, the infrastructure enables testing of a variety of transactions from multiple sources. Additionally, clearinghouse testing may now be automated.

US Patent:

20110215717, Sep 8, 2011

Filed:

Mar 4, 2010

Appl. No.:

12/660890

Inventors:

Ping Chen - Rancho Palos Verdes CA, US
Martin L. Lundquist - Rancho Palos Verdes CA, US
David U.L. Yu - Rancho Palos Verdes CA, US

International Classification:

H01J 21/00
H01J 5/16
H01J 1/34

US Classification:

313542, 313325, 313110, 313233

Abstract:

A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

US Patent:

20110215791, Sep 8, 2011

Filed:

Mar 2, 2010

Appl. No.:

12/660731

Inventors:

Ping Chen - Rancho Palos Verdes CA, US
Martin L. Lundquist - Rancho Palos Verdes CA, US
David U.L. Yu - Rancho Palos Verdes CA, US

International Classification:

H02M 3/156

US Classification:

323351

Abstract:

A novel design scheme for the compensation circuitry of solid-state Marx modulators has been described for enhancing the compensation ability of the compensation cells of the Marx modulators and simplifying the entire circuitry. High-speed solid-state switches are adopted in the compensation circuitry for the control of the compensation actions. Inductive components and diodes are used in the design scheme to smooth voltage curve.

US Patent:

20120229053, Sep 13, 2012

Filed:

Mar 8, 2011

Appl. No.:

12/932891

Inventors:

David U.L. Yu - Rancho Palos Verdes CA, US
Yan Luo - Manhattan Beach CA, US

International Classification:

H05H 9/04

US Classification:

315505

Abstract:

A photoelectron linear accelerator for producing a low emittance polarized electron beam. The linear accelerator includes a tube having a cylindrical wall, said wall being perforated to allow gas to flow to a pressure chamber containing ultra high vacuum pumps located outside the accelerator. The RF accelerator cavity comprises of two concentric cylindrical regions having different outside diameters and different lengths.

US Patent:

20120326528, Dec 27, 2012

Filed:

Jul 10, 2012

Appl. No.:

13/507589

Inventors:

Ping Chen - Rancho Palos Verdes CA, US
Martin L. Lundquist - Rancho Palos Verdes CA, US
David U.L. Yu - Rancho Palos Verdes CA, US

International Classification:

H03K 3/017

US Classification:

307108

Abstract:

A novel design scheme for the compensation circuitry of solid-state Marx modulators has been described for enhancing the compensation ability of the compensation cells of solid-state Marx modulators and simplifying the entire circuitry of the modulator. High-speed solid-state switches are adopted in the new compensation cell for the control of the compensation actions. Inductive components and diodes are adopted in the design scheme to smooth the flattop of the voltage pulse output by the Marx modulator.