Performance comparison on various parameters of area dependent capacitive accelerometer and air gap dependent capacitive accelerometer for high frequency applications

Microelectronics and mechanical system (MEMS) capacitive accelerometers are very much required for high frequency applications like weapons navigation, submarine navigation and many more. Here, authors design MEMS capacitive accelerometers and also compare their performances. The bulk micro machined multiple beams area changed capacitance accelerometer and air gap comb drive capacitive accelerometer structures are designed. Generally in capacitive accelerometers due to high gap between parallel plates linearity is high and sensitivity is low and vice versa. It is not possible for achieving high linearity and sensitivity at a time. Here, authors concentrated to achieve high mechanical sensitivity and high voltage sensitivity with better linearity for capacitive Accelerometers. So authors performed some analysis like non-linearity, capacitive, noise, temperature, displacement and voltage sensitivity in various works for both the capacitive accelerometers and compared. The cross axis sensitivity for air gap is 10.75% and for area is 0.45%, voltage sensitivity for air is 0.3642 V/g and for area is 0.8466 V/g. Noise figure for air is 0.428 \(\frac{ug}{{\sqrt {{\text{hz}}} }}\) and noise figure for area is 3.73 pg/\(\sqrt {{\text{Hz}}}\), Mechanical sensitivity for air is 0.007 µm/g and for area is 0.26 µm/g and linearity is nearly equal to both the capacitive accelerometers. From all these comparisons authors concluded that area changed capacitive accelerometer is best one when compared to air gap changed accelerometer. The primary advantage of this structure is that no changes to the fabrication process flow are required when constructing it.