Caracteritzation of noise in MEMS accelerometres for femtosats
Tutor / director / evaluatorGutiérrez Cabello, Jordi
Document typeBachelor thesis
Rights accessOpen Access
The aim of this thesis is to determine the characteristics of the noise of an ultralow noise MEMS accelerometer. The study of these characteristics will allow to determine if the accelerometer can be used in the scientific payload aboard a femtosat. And it the case that it is used, it will allow to calibrate the accelerometer to provide a better signal. The method for studying the noise characteristics is the Allan Variance, which allows to identify and determine the most important noise terms that affect accelerometers. An experiment to perform the Allan Variance has been designed and performed. The sensor studied is ultralow noise and for this reason it must be isolated from its surroundings during the experiment, which will corrupt the output signal and not allow to clearly study the noise of the sensor. To achieve this task two isolations systems have been designed and built, one for protecting the sensor from vibrations transmitted through air like currents of air created either naturally or by people moving in the room of the experiment. And another to isolate the sensor from vibrations travelling through ground such as the natural vibrations of the ground or vibrations caused moving objects in contact with the floor or people walking. These isolation systems have been installed in an underground laboratory located on the EETAC campus to ensure that there almost no sources of vibration present during the experiment and that there are no changes in the temperature. The isolation systems have worked properly and the sensor has not been affected by external accelerations. The results obtained are satisfactory, they agree with the information provided by the datasheet and it is considered that the sensor noise properties have been characterized properly. Even though the results are satisfactory, it cannot be yet defined if the sensor will be used for the scientific payload aboard a femtosat.