Micromechanical device for the measurement of the RMS value of high-frequency voltages

Abstract

In this paper we present a new device for the measurement of the root-mean square (rms) value of high frequency (HF) voltages. The device is realized as a micromachined structure which responds to electrostatic forces caused by applied voltages. The structure has a seesaw-like geometry and is made of silicon. At frequencies much higher than the mechanical resonance frequency the system will not follow the stimulating sinusoidal waveform any more, but it is deflected according to the rms value of the HF voltage. The deflection can be determined by a wheatstone bridge consisting of two on-chip capacitors and two external resistors or by measuring a single capacitor.