Paul M Ward

US Patent:

6873206, Mar 29, 2005

Filed:

Apr 19, 2001

Appl. No.:

09/839184

Inventors:

Eric M. Hildebrant - Watertown MA, US
Paul A. Ward - Roslindale MA, US
Robert A. Bousquet - Somerville MA, US
Shida Iep Martinez - Andover MA, US
Harold Ralph Haley - Reading MA, US

Assignee:

Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G06G007/26

US Classification:

327560, 327561, 327563, 330253, 330259, 330260

Abstract:

A fully integrated charge amplifier with DC stabilization includes a first amplifier having an input terminal and an output terminal, a first capacitor coupled between the input terminal and the output terminal of the first amplifier, a transimpedance amplifier having an input terminal coupled to the output terminal of the first amplifier and an output terminal, and an impedance device coupled between the input terminal of the first amplifier and the output terminal of the second amplifier. The impedance device has a resistance of at least 1 MΩ.

US Patent:

7231094, Jun 12, 2007

Filed:

Oct 1, 2002

Appl. No.:

10/262635

Inventors:

James A. Bickford - Winchester MA, US
Paul Ward - Roslindale MA, US

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G06K 9/36

US Classification:

382248, 382280

Abstract:

Apparatus and methods for performing a Fourier transform mechanically, using an array of one or more resonators. By tuning the resonators so that their natural frequencies correspond to harmonics of an input signal, the vibration of the resonators in response to the input signal may be measured to provide phase and amplitude information that is equivalent to the Fourier coefficients of the input signal. Preferably, the resonators are microelectromechanical (MEMS) resonators. Using MEMS resonators, the Fourier transform of a signal can be determined using substantially less power than would be consumed by a digital signal processor (DSP) or microprocessor performing similar calculations. MEMS resonator-based apparatus and methods according to various embodiments may be used for applications including compression and image processing.

US Patent:

7817284, Oct 19, 2010

Filed:

Jun 27, 2008

Appl. No.:

12/163621

Inventors:

Paul A. Ward - Dedham MA, US

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G01C 19/72

US Classification:

356460

Abstract:

Interference in a rotation rate detector signal of an interferometric fiber-optic gyroscope from a bias phase modulator signal may be reduced or substantially avoided by transmitting one or more off-frequency signals having a frequency other than the eigenfrequency of the gyroscope towards a bias phase modulator, generating the bias phase modulator signal having a frequency substantially equal to the eigenfrequency of the gyroscope, and driving the bias phase modulator with the bias phase modulator signal.

US Patent:

7872758, Jan 18, 2011

Filed:

Jan 22, 2008

Appl. No.:

12/018016

Inventors:

Paul A. Ward - Dedham MA, US
Michael Kishinevsky - North Andover MA, US
Matthew Soucy - Hopkinton MA, US
Stephen P. Smith - Acton MA, US
Farhad Zarinetchi - Chelmsford MA, US

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G01C 19/72

US Classification:

356460

Abstract:

Determining linear modulator dynamics in an interferometric fiber-optic gyroscope may be accomplished by applying a stimulus at a point within the gyroscope, observing a response in an output of the gyroscope, and determining, from the observed response, the linear modulator dynamics.

US Patent:

8102536, Jan 24, 2012

Filed:

Dec 9, 2010

Appl. No.:

12/963977

Inventors:

Paul A. Ward - Dedham MA, US
Michael Kishinevsky - North Andover MA, US
Matthew Soucy - Hopkinton MA, US
Stephen P. Smith - Acton MA, US
Farhad Zarinetchi - Chelmsford MA, US

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G01B 9/02

US Classification:

356460

Abstract:

Determining linear modulator dynamics in an interferometric fiber-optic gyroscope may be accomplished by applying a stimulus at a point within the gyroscope, observing a response in an output of the gyroscope, and determining, from the observed response, the linear modulator dynamics.

US Patent:

56083513, Mar 4, 1997

Filed:

May 24, 1995

Appl. No.:

8/449724

Inventors:

Paul Ward - Waltham MA

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

H03F 134

US Classification:

330107

Abstract:

Electronics for use in Coriolis and other sensors for reducing errors in the sensor output signal. An off-frequency drive scheme includes a frequency translation circuit in the excitation feedback loop of a sensor system to suppress components of the sensor drive signal at a predetermined frequency so that coupling of the drive signal to the sensor output signal can be readily removed by conventional filtering techniques. An amplifier circuit having a bandpass circuit in cascade with the forward loop gain is provided, with the bandpass circuit having a transfer function approximating one plus a bandpass characteristic, the passband of which corresponds to the information band. This arrangement increases the open-loop gain of the amplifier circuit around the information frequency without affecting the open-loop gain at DC and crossover so as to reduce phase and gain errors around the information frequency. A quadrature hulling system is provided for an in-plane micromechanical gyroscope. A signal having an in-phase component due to Coriolis induced out-of-plane motion and a quadrature component due to mechanical misalignments is mixed with a voltage in-phase with motor position.

US Patent:

53631951, Nov 8, 1994

Filed:

Dec 24, 1992

Appl. No.:

7/996724

Inventors:

Paul A. Ward - Waltham MA
Joseph G. Walsh - Cambridge MA

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G01C 1972

US Classification:

356350

Abstract:

An automatic gain calibration system for a phase modulator for forcing a predetermined phase shift amplitude includes a phase modulator responsive to an applied voltage for modulating the phase of a radiation beam. The frequency spectrum of the modulated radiation beam is converted to the electrical domain where a selected even harmonic of the spectrum is nulled. The scaling circuit then responds to the amplitude of voltage applied to the phase modulator that obtains the phase shift which produced the nulling of the selected even harmonic and scales that voltage to generate the predetermined phase shift amplitude which is desired.

US Patent:

59525746, Sep 14, 1999

Filed:

Apr 29, 1997

Appl. No.:

8/841224

Inventors:

Marc S. Weinberg - Needham MA
Steven T. Cho - Santa Clara CA
Ralph E. Hopkins - Brookline MA
Lance C. Niles - Salem MA
Anthony S. Kourepenis - Acton MA
Eric M. Hildebrant - Watertown MA
Paul A. Ward - Roslindale MA

Assignee:

The Charles Stark Draper Laboratory, Inc. - Cambridge MA

International Classification:

G01C 1900

US Classification:

7350416

Abstract:

Trenches which reduce or eliminate force and sensitivity associated with proof mass motion normal to the substrate as a result of voltage transients is disclosed. The trenches provide increased separation between interleaved comb electrodes and the substrate, and thereby also reduce the comb lift to drive ratio. The trenches are typically formed directly below the interleaved comb electrodes, but may also be formed below other suspended portions. Trench depth is from 6-10 microns and provides a comb electrode to substrate separation of approximately 8. 5-12. 5 microns.