Resonance-based MEMS temperature sensors for temperature compensation of mems capacitive accelerometer

Download
2016
Demirhan, Gülşah
The idea of the proposed study is using the resonator structure as a temperature sensor together with controller circuitry. That is to say, the study consists of two branches; one is PI controller output which would be used as a temperature sensor and the other is preamplifier output which would be used as carrier generator to the accelerometer readout circuitry. The proposed resonator is analyzed in detail in terms of dynamics, simulation models and theoretical investigations. The implemented resonator is shown to satisfy the estimated performance parameters with measurements conducted using various test setups. The functionality of concept is verified with additional tests. In other words, it is gathered repeatable temperature sensitivity data from both the accelerometer and the resonating temperature sensor. Then, initially the temperature sensitivity of the accelerometer output with the controller output of the resonating accelerometer is compensated. Once the attempt in the first step is succeed, the temperature compensation network is disassembled and the resonator output to the accelerometer package as the carrier signal is fed. This eliminates the need for an external carrier waveform generated by a standard clock generator, which can be one of the dominant noise sources injected into the accelerometer system. After this new interconnection is made, the temperature sensitivity of the accelerometer is measured. By doing that, it is aimed to observe that the temperature sensitivity of the accelerometer is the same as before compensation, while it is driven by the resonator output as the carrier signal. Finally, the compensation network will be re-assembled while still feeding the accelerometer with the output of the resonator, and it is tried to repeat the compensated accelerometer response that was previously observed at the first step. The best system level test results showed that the temperature sensitivity is improved from -32 mg/°C to -1.6 µg/°C for -35 µg/√Hz noise floor, 16 µg bias instability and 122 dB dynamic range.

Suggestions

Development of an integrated resonant MEMS temperature sensor
Köse, Talha; Azgın, Kıvanç; Akın, Tayfun; Department of Mechanical Engineering (2016)
This thesis presents the design, fabrication and characterization of a high performance, integrated, resonant MEMS temperature sensor, and temperature compensation of a capacitive MEMS accelerometer. Two different double-ended-tuning-fork (DETF) type resonator designs are developed and characterized for temperature sensing. The strain-amplifying beam structure is added to the DETF resonators in order to enhance thermal strain induced on the DETF tines due to the different thermal expansion coefficients of t...
Shape optimization of MEMS switches for miniaturization
Ahmed, Imran; Dal, Hüsnü; Ünlü, Mehmet; Department of Mechanical Engineering (2018)
This thesis presents miniature optimized cantilever beam MEMS contact switches for low pull-in voltage, low switching time and relatively high contact force for stable switch operation. Beam based MEMS switches are promising replacements of CMOS based p-i-n diodes and field effect transistor (FET) diode switches due to structural and operation advantages over these solid state switches. High isolation, zero power consumption and very low manufacturing cost are promising advantages compared to solid state sw...
A Versatile 5th order sigma-delta modulation circuit for MEMS capacitive accelerometer characterization /
Asgarli, Tunjar; Akın, Tayfun; Department of Electrical and Electronics Engineering (2014)
With the significant developments in capacitive MEMS inertial sensors, tons of studies in the literature trying to enhance the performance parameters of MEMS capacitive accelerometer systems such as linearity, noise floor and bandwidth further has emerged. However, all the studies are conducted on a certain reference point, which is mainly the properties of the accelerometer sensor that alter a lot in the design of the high performance interface readout circuit. The designed interface circuits usually adopt...
Compensation methos for quasi-static acceleration sensitivity of MEMS gyroscopes /
Gavcar, Hasan Doğan; Azgın, Kıvanç; Department of Electrical and Electronics Engineering (2014)
This thesis presents the quasi-static acceleration compensation methods for a fully decoupled MEMS gyroscope. These methods are based on the utilization of the amplitude difference information between the residual quadrature signals on the differential sense mode electrodes to sense the static acceleration acting on the sense mode of the gyroscope. There are three different quasi-static acceleration compensation methods presented in this thesis. In the first method, the static acceleration is measured by co...
A Readout circuit for resonant MEMS temperature sensors
Asadi, Hamed; Akın, Tayfun; Azgın, Kıvanç; Department of Electrical and Electronics Engineering (2016)
High precision is the dominant advantage that resonant sensors have over other types of analog sensors (sensors with a subsequent analog-to-digital converter). The resolution of these precise sensors is determined by both frequency resolution and sensitivity of the sensor. The sensitivity is highly related to the sensitivity of the MEMS resonator. However, the frequency resolution is dominantly defined by the closed-loop circuitry if noise contribution of the resonator is assumed to be smaller than that of ...
Citation Formats
G. Demirhan, “Resonance-based MEMS temperature sensors for temperature compensation of mems capacitive accelerometer,” M.S. - Master of Science, Middle East Technical University, 2016.