Micro yaw rate sensors
First Claim
1. A micro yaw rate sensor comprising:
- a) a base substrate wafer made of piezoelectric material;
b) a pair of suspensions, namely a first suspension and a second suspension;
c) a proof mass connected to said base substrate by said first suspension and said second suspension from two opposite sides;
d) a plurality of driving electrodes disposed on top and bottom surfaces of said first suspension;
e) a plurality of sensing electrodes disposed on top and bottom surfaces of said second suspension;
wherein, an electric potential is impressed on said driving electrodes to excite a driving resonance within said substrate wafer plane, while occurrence of a sensing resonance caused by Coriolis force in direction out of said substrate wafer plane and perpendicular to said driving resonance is detected by electrical measurement from said sensing electrodes, and said sensing resonance is an indication of yaw rate.
0 Assignments
0 Petitions
Accused Products
Abstract
Yaw rate sensors are provided, the use of which permits quantitative measurement of yaw rate. The yaw rate sensor comprises at least a base, a first suspension and a second suspension with a proof mass supported between the two suspensions, which together form a resonator. The first suspension has a pair of thin-wire driving electrodes double side patterned on the surfaces. When a driving voltage is applied to the driving electrodes, it imposes an electric field to piezoelectrically induce a driving resonance. When the sensor is rotated around its sensing axis, the resonator will be forced to generate a sensing resonance out of the driving resonance plane to compensate the change in the linear momentum which must be conserved. The piezoelectric charge signal generated by the sensing resonance on the sensing electrodes which are double side patterned on the surfaces of the second suspension is used to detect the yaw rate. Specifically, the amplitude of the sensing resonance is in proportion to the yaw rate. The structure of the yaw rate sensors of this invention is suitable for mass production by lithographic micromachining techniques at low cost.
-
Citations
17 Claims
-
1. A micro yaw rate sensor comprising:
-
a) a base substrate wafer made of piezoelectric material;
b) a pair of suspensions, namely a first suspension and a second suspension;
c) a proof mass connected to said base substrate by said first suspension and said second suspension from two opposite sides;
d) a plurality of driving electrodes disposed on top and bottom surfaces of said first suspension;
e) a plurality of sensing electrodes disposed on top and bottom surfaces of said second suspension;
wherein, an electric potential is impressed on said driving electrodes to excite a driving resonance within said substrate wafer plane, while occurrence of a sensing resonance caused by Coriolis force in direction out of said substrate wafer plane and perpendicular to said driving resonance is detected by electrical measurement from said sensing electrodes, and said sensing resonance is an indication of yaw rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
-
Specification