Question

Que.) How does Bulk micromachined variable capacitor works?

Bulk micro-machined variable capacitors comb-drive most successful Capacitor gap Stationary fingers Movable fingers Folded-beam spring Anchor and electrical contact Anchor and electrical contact Motion

need answer ASAP.

Answer 1

The Bulk micromachined variable capacitor combines the principle of Parallel plate capacitor and Comb drive actuators . Here via the electrical contacts the voltage is applied to the stationary and moving fingers of the combs , this causes an attractive Electrostatic force between them causing them to draw against each other , That CAUSES THE Area VARIATION BETWEEN THE FINGERS AND SO THE CAPACITOR BECOMES A VARIABLE MODEL DEPENDING UPON HOW MUCH AREA IS BEING VARIED .

AREA CAUSES CAPACITANCE VARIATION BECAUSE ,

C={ $\epsilon$ A / d} is the capacitance and it directly varies with Area of plates . So when comb drive actuates it causes plates area to vary giving us variable capacitance . This is called micromachined since components used here are made by use of microscopic Or very small size level techniques like deposition and etching over a substrate.