Thomas C Weldon

US Patent:

D458003, Jun 4, 2002

Filed:

Jun 26, 2000

Appl. No.:

29/125521

Inventors:

Thomas Paul Weldon - Charlotte NC 28277
Kristen Marie Weldon - Charlotte NC 28277
Kerry Rebecca Weldon - Charlotte NC 28277

International Classification:

0101

US Classification:

D 1129

US Patent:

6794938, Sep 21, 2004

Filed:

Mar 19, 2002

Appl. No.:

10/101005

Inventors:

Thomas Paul Weldon - Charlotte NC

Assignee:

The University of North Carolina at Charlotte - Charlotte NC

International Classification:

H03F 126

US Classification:

330149, 330124 R, 333117

Abstract:

Methods and apparatus are provided for substantially reducing and/or canceling nonlinearities of any order in circuits, devices, and systems such as amplifiers and mixers. In particular, methods and apparatus are provided for substantially reducing and/or canceling third order nonlinearities in circuits, devices, and systems such as amplifiers and mixers. A first coupler is used to split an input signal into two equal-amplitude in-phase components, each component is processed by two nonlinear devices with different nonlinearities, and a final combiner, such as a 180-degree hybrid, recombines the processed signals 180 degrees out of phase and substantially reduces and/or cancels the undesired nonlinear distortion components arising due to nonlinearities in the nonlinear devices.

US Patent:

6833724, Dec 21, 2004

Filed:

Sep 10, 2002

Appl. No.:

10/237670

Inventors:

David M. Binkley - Charlotte NC
Rafic Zein Makki - Charlotte NC
Thomas Paul Weldon - Charlotte NC
Ali Chehab - Beirut, LB

Assignee:

University of North Carolina at Charlotte - Charlotte NC

International Classification:

G01R 3126

US Classification:

324765

Abstract:

Methods and apparatus are provided for testing to determine the existence of defects and faults in circuits, devices, and systems such as digital integrated circuits, SRAM memory, mixed signal circuits, and the like. In particular, methods and apparatus are provided for detecting faults in circuits, devices, and systems using input control signals to generate controlled-duration, controlled pulse-width, transient power supply currents in a device under test, where said transient power supply currents are of controllable bandwidth and can be used as observables to determine faulty or defective operation. Additionally, methods and apparatus are provided to permit high bandwidth sensing of transient supply currents as need to preserve the narrow widths of these current pulses. These methods may include autozero techniques to remove supply current leakage current and DC offsets associated with practical current sensing currents. The sensed transient supply currents can be compared to single or multiple thresholds to assess normal or faulty or defective operation of the device under test.

US Patent:

6853247, Feb 8, 2005

Filed:

Mar 5, 2004

Appl. No.:

10/793998

Inventors:

Thomas Paul Weldon - Charlotte NC, US

Assignee:

The University of North Carolina at Charlotte - Charlotte NC

International Classification:

H03F001/26

US Classification:

330149, 330277

Abstract:

Methods and apparatus are provided for substantially reducing and/or canceling nonlinearities of any order in circuits, devices, and systems such as amplifiers and mixers. In particular, methods and apparatus are provided for substantially reducing and/or canceling third order nonlinearities in circuits, devices, and systems such as amplifiers and mixers. A first coupler is used to split an input signal into two equal-amplitude in-phase components, each component is processed by two nonlinear devices with different nonlinearities, and a final combiner, such as a 180-degree hybrid, recombines the processed signals 180 degrees out of phase and substantially reduces and/or cancels the undesired nonlinear distortion components arising due to nonlinearities in the nonlinear devices.

US Patent:

6853248, Feb 8, 2005

Filed:

Mar 5, 2004

Appl. No.:

10/794000

Inventors:

Thomas Paul Weldon - Charlotte NC, US

Assignee:

The University of North Carolina at Charlotte - Charlotte NC

International Classification:

H03F001/26

US Classification:

330149, 330124 R

Abstract:

Methods and apparatus are provided for substantially reducing and/or canceling nonlinearities of any order in circuits, devices, and systems such as amplifiers and mixers. In particular, methods and apparatus are provided for substantially reducing and/or canceling third order nonlinearities in circuits, devices, and systems such as amplifiers and mixers. A first coupler is used to split an input signal into two equal-amplitude in-phase components, each component is processed by two nonlinear devices with different nonlinearities, and a final combiner, such as a 180-degree hybrid, recombines the processed signals 180 degrees out of phase and substantially reduces and/or cancels the undesired nonlinear distortion components arising due to nonlinearities in the nonlinear devices.

US Patent:

6906585, Jun 14, 2005

Filed:

Mar 5, 2004

Appl. No.:

10/794005

Inventors:

Thomas Paul Weldon - Charlotte NC, US

Assignee:

The University of North Carolina at Charlotte - Charlotte NC

International Classification:

H03F001/26

US Classification:

330149, 330124 R

Abstract:

Methods and apparatus are provided for substantially reducing and/or canceling nonlinearities of any order in circuits, devices, and systems such as amplifiers and mixers. In particular, methods and apparatus are provided for substantially reducing and/or canceling third order nonlinearities in circuits, devices, and systems such as amplifiers and mixers. A first coupler is used to split an input signal into two equal-amplitude in-phase components, each component is processed by two nonlinear devices with different nonlinearities, and a final combiner, such as a 180-degree hybrid, recombines the processed signals 180 degrees out of phase and substantially reduces and/or cancels the undesired nonlinear distortion components arising due to nonlinearities in the nonlinear devices.

US Patent:

6943628, Sep 13, 2005

Filed:

Mar 5, 2004

Appl. No.:

10/793999

Inventors:

Thomas Paul Weldon - Charlotte NC, US

Assignee:

The University of North Carolina at Charlotte - Charlotte NC

International Classification:

H03F001/26

US Classification:

330149, 330151

Abstract:

Methods and apparatus are provided for substantially reducing and/or canceling nonlinearities of any order in circuits, devices, and systems such as amplifiers and mixers. In particular, methods and apparatus are provided for substantially reducing and/or canceling third order nonlinearities in circuits, devices, and systems such as amplifiers and mixers. A first coupler is used to split an input signal into two equal-amplitude in-phase components, each component is processed by two nonlinear devices with different nonlinearities, and a final combiner, such as a 180-degree hybrid, recombines the processed signals 180 degrees out of phase and substantially reduces and/or cancels the undesired nonlinear distortion components arising due to nonlinearities in the nonlinear devices.

US Patent:

7148717, Dec 12, 2006

Filed:

Jul 28, 2004

Appl. No.:

10/900915

Inventors:

David M. Binkley - Charlotte NC, US
Rafic Zein Makki - Charlotte NC, US
Thomas Paul Weldon - Charlotte NC, US
Ali Chehab - Beirut, LB

Assignee:

University of North Carolina at Charlotte - Charlotte NC

International Classification:

G01R 31/26

US Classification:

324765

Abstract:

Methods and apparatus are provided for testing to determine the existence of defects and faults in circuits, devices, and systems such as digital integrated circuits, SRAM memory, mixed signal circuits, and the like. In particular, methods and apparatus are provided for detecting faults in circuits, devices, and systems using input control signals to generate controlled-duration, controlled pulse-width, transient power supply currents in a device under test, where said transient power supply currents are of controllable bandwidth and can be used as observables to determine faulty or defective operation. Additionally, methods and apparatus are provided to permit high bandwidth sensing of transient supply currents as need to preserve the narrow widths of these current pulses. These methods may include autozero techniques to remove supply current leakage current and DC offsets associated with practical current sensing currents. The sensed transient supply currents can be compared to single or multiple thresholds to assess normal or faulty or defective operation of the device under test.