Balanced angular accelerometer

An angular accelerometer comprising:

• a substrate;
• a first bank of variable capacitors formed of a first plurality of fixed capacitive plates and a first plurality of movable capacitive plates;
• a second bank of variable capacitors formed of a second plurality of fixed capacitive plates and a second plurality of movable capacitive plates;
• a rotational inertia mass configured as a ring having a central opening and rotatable in response to angular acceleration and electrically coupled to said first and second plurality of movable capacitive plates and arranged so that said first and second plurality of movable capacitive plates form capacitive couplings with said first and second plurality of fixed capacitive plates;
• a central member fixed to said substrate and centrally located within said central opening of the rotational inertia mass and separated from the rotational inertia mass;
• an outer member supported on the substrate and located radially outward from the rotational inertia mass;
• a first plurality of support arms extending between said central member and said rotational inertia mass;
• and
• a second plurality of support arms extending between said rotational inertia mass and said outer member, wherein the first and second plurality of support arms support said rotational inertia mass and movable capacitive plates relative to said first and second fixed capacitive plates and further allow rotational movement of the rotational inertia mass upon experiencing an angular acceleration about a sensing axis.

A micromachined angular accelerometer comprising:

• a substrate;
• a fixed electrode supported on the substrate and including a first plurality of fixed capacitive plates;
• a rotational ring having a central opening and including a plurality of movable capacitive plates at the outer perimeter and arranged to provide a capacitive coupling with the first plurality of fixed capacitive plates, said rotational ring being suspended over a cavity and rotationally movable relative to said fixed electrode;
• a central member fixed to said substrate and located within the central opening of the rotational ring;
• an outer member fixed to said substrate and located radially outward from said rotational ring;
• a first plurality of support arms extending between said central member and the rotational ring;
• a second plurality of support arms extending between said rotational ring and said outer member, wherein the first and second plurality of support arms support said rotational ring relative to said fixed electrode and allow rotational movement of the rotational ring upon experiencing an angular acceleration about a sensing axis;
• an input electrically coupled to one of the fixed electrode and the rotational ring for receiving an input signal;
• and
• an output electrically coupled to the other of the fixed electrode and the rotational ring for providing an output signal which varies as a function of change in the capacitive coupling and is indicative of angular acceleration.