Optimal Selection of Capacitive Sensor Frequency Margin

Abstract

To choose the appropriate frequency range, it is necessary to understand the physical behavior of the sensor in different situations. The natural frequency of a capacitive accelerometer is an integral part of its design and material characteristics, and it influences the response of the sensor to various frequencies of vibrational inputs. If the frequency of the vibrating movements is too close to the natural frequency of the accelerometer, this can lead to resonance, which leads to strong oscillations and considerable measurement errors. During our research, we created a comprehensive model to represent the operation of the capacitive accelerometer. This model includes the essential elements that impact sensor performance, such as mass, damping and stiffness, as well as the electrical characteristics of the capacitive sensing mechanism. The study of this model under different conditions made it possible to observe the reaction of the accelerometer to various frequencies of vibration inputs. These simulations allowed us to relate the natural frequency of the accelerometer to the frequency of the vibratory movements. It is essential to take this relationship into account to define the ideal frequency range for the accelerometer. By entering this link, it is possible to choose a frequency range that prevents resonance and reduces measurement errors, improving the accuracy and reliability of the sensor output.