Steven C Patterson

US Patent:

6556417, Apr 29, 2003

Filed:

Apr 13, 2001

Appl. No.:

09/834691

Inventors:

Robert B. McIntosh - Alexandria VA 22314
Philip E. Mauger - Santa Clara CA 95051
Steven R. Patterson - Concord NC 28027

International Classification:

H01G 501

US Classification:

361278

Abstract:

A method to construct a capacitive transducers comprising the steps of forming over and in a planar surface of a substrate at least one rigid electrode of a variable-area capacitor electrically connected to a location on said substrate reserved for electrode attachment; providing a cooperating flexible electrode with a dielectric layer; and bonding said flexible electrode to said substrate in a surface region surrounding said rigid electrode.

US Patent:

6661637, Dec 9, 2003

Filed:

Sep 18, 2001

Appl. No.:

09/954670

Inventors:

Robert B. McIntosh - Alexandria VA 22314
Steven R. Patterson - Concord NC 28027

International Classification:

H02H 2300

US Classification:

361233, 361207, 361225

Abstract:

A micro-opto-electro-mechanical transducer in which an optical element is angularly positioned by electrical field coupling. Movable electrodes of two orthogonally disposed, differential variable capacitors are coupled to the optical element constrained by structural means to angular displacement around two free-axes of rotation. Cooperating stationary capacitor electrodes with surface contoured regions facing the movable electrodes are affixed to the structural means. A thin dielectric layer of high permittivity material provides a region of fixed spacing between the capacitor electrodes. The surface contoured regions constrain the approach of the movable electrodes with angular displacement of the optical element. Both the open-loop gain and the equilibrium voltage-angle response of the transducer is largely independent of displacement. Electrostatic force feedback maintains the optical element at voltage programmed positions of static equilibrium over a wide angular range of tip and tilt.

US Patent:

20010020850, Sep 13, 2001

Filed:

Mar 24, 2001

Appl. No.:

09/816551

Inventors:

Robert McIntosh - Alexandria VA, US
Steven Patterson - Concord NC, US

International Classification:

H01H073/00

US Classification:

324/519000, 361/115000

Abstract:

A capacitance measurement circuit detects a change in capacitance between a variable capacitor and a fixed reference capacitor in a bridge network and provides feedback current to null-balance the bridge. An error signal is amplified at high gain by a differential integrator having an output that is converted to a high-frequency stream of digital pulses of constant amplitude and width. The pulse stream is integrated to provide a voltage to control feedback current used to balance the bridge. The average pulse density per unit time, or the frequency of the digital pulses, is linearly proportional to a change in capacitance of said variable capacitor to high accuracy over a wide dynamic range.

US Patent:

61519677, Nov 28, 2000

Filed:

Mar 10, 1998

Appl. No.:

9/037733

Inventors:

Robert B. McIntosh - Alexandria VA
Philip E. Mauger - Santa Clara CA
Steven R. Patterson - Concord NC
Gene A. Goodman - Rockville MD

Assignee:

Horizon Technology Group - Alexandria VA

International Classification:

G01P 15125
G01L 912

US Classification:

7351432

Abstract:

A variable area capacitor with a flexible electrode responsive to a physical effect and a rigid electrode with a predetermined surface contour. The surface contour is dimensioned to provide a specific change in capacitance with deflection of the flexible electrode. A thin dielectric layer maintains a substantially fixed spacing between the two electrodes. Preferred embodiments include a pressure sensor, microphone and accelerometer. A differential transconductance amplifier detects changes of the variable capacitor in a low-impedance, bridge-like circuit and feeds back current to balance the bridge. The voltage that controls the feedback current is proportional to capacitance over a wide dynamic range.