Design and simulation of a MEMS decoupled single proof mass three-axis capacitive accelerometer with ultra-low cross-axis error
摘要
This article presents a novel single proof mass three-axis capacitive accelerometer. This accelerometer’s design is developed to effectively reduce the influence of cross-axis errors on each axis. The elimination of cross-axis coupling is achieved through dual-decoupled frame architectures. A fully differential approach is used for the capacitive sensing mechanism on all three axes. The overall dimensions of the presented accelerometer in this paper are 1.6 × 1.6 mm2, with a measurement range of ± 10 g. The simulation results show sensitivity, with values of 31.11 fF/g, 31.46 fF/g, and 36.26 fF/g for the respective x, y, and z axes. Moreover, the value of nonlinearity in the x, y, and z axes is as low as 0.28, 0.29, and 0.05% of full scale, respectively. Furthermore, a symmetrical design guarantees that the structure exhibits minor thermal sensitivity. The mechanical noise of the accelerometer is 7.5 µg/√Hz for in-plane axes and 10.8 µg/√Hz for the vertical axis. In order to validate the design’s parameters, the COMSOL software was used to carry out simulations of the proposed structure.