Philip Stephen Mauger

6556417, Apr 29, 2003

Apr 13, 2001

09/834691

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

H01G 501

361278

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.

61519677, Nov 28, 2000

Mar 10, 1998

9/037733

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

Horizon Technology Group - Alexandria VA

G01P 15125
G01L 912

7351432

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.