CMOS readout electronics for mis-matched and mode-matched MEMS gyroscopes

Yeşil, Ferhat
This thesis presents the CMOS readout electronics for both mismatched and mode-matched MEMS gyroscopes. A systematic design of MEMS gyroscope's control loop parameters, which is insensitive to sensor parameters and environmental conditions, is necessary for robust and high performance operation. Extra to the systematic design for high performance operation, some special techniques should be used to further increase the performance of the sensor. In this thesis, as a performance increasing technique, mode-matching method is applied to increase the signal to electronic noise ratio. This is achieved by injecting a perturbation signal to the quadrature cancellation loop, while keeping it decoupled from the angular rate control loop. This injected perturbation signal is used to detect the amount of frequency mismatch that is fed to the mode-match controller in order to tune the sense mode resonance frequency by using spring softening effect. This new controller is implemented in a CMOS ASIC together with the other sensor control loops, and it is verified to maintain matched-mode state under changing environmental conditions. The system reduces the overall output noise of the tested MEMS gyroscope by a factor of 6; truly reaching down to the thermo-mechanical noise floor of 0.23 hr)/√Hz. This performance is obtained with 22mm x 22m packaging and 125mW power consumption.


A Low-power capacitive integrated CMOS readout circuitry for high performance MEMS accelerometers
İncedere, Osman Samet; Akın, Tayfun; Eminoğlu, Selim; Department of Electrical and Electronics Engineering (2013)
This thesis presents a low power capacitive integrated CMOS readout circuitry for high performance MEMS accelerometers. It proposes a linearized model of the complete closed loop accelerometer system, which makes easier of designing and analyzing the system. Designed readout circuitry offers low noise, wide dynamic range and high linearity system with very low power consumption. Designed readout circuit includes proportional integral (PI) controller circuit, which significantly decreases the proof mass defl...
Efficiency improvement of power amplifiers without degraded linearity using a new topology and control method
Ronaghzadeh, Amin; Demir, Şimşek (2011-11-21)
This paper presents a medium-power amplifier designed in class AB at 2.4 GHz with two transistors of the same type in parallel. Keeping the drain bias of the transistors constant, it is demonstrated that by careful selection of the transistor and dynamically tuning the gate bias of the individual devices and output matching of the whole amplifier according to input drive level, an increase of about 40% in PAE is achieved at 7 dB back-off from the P1dB of the class AB amplifier employing a fixed bias and mat...
Low-cost microbolometer infrared detectors utilizing CMOS resistive layers
Öztürk, Hande; Akın, Tayfun; Department of Electrical and Electronics Engineering (2017)
This thesis presents the efforts to develop low-cost microbolometer type uncooled infrared detector architectures that utilize standard CMOS layers and components. Various resistance structures of different CMOS technologies are investigated and possible resistors are determined as the active material. In order to figure out potential microbolometer structure, all possible layers in the CMOS technologies are analyzed in terms of mechanical and thermal parameters. Mathematical modeling and computer simulatio...
Surface energy and excess charge in (1x2)-reconstructed rutile TiO2(110) from DFT plus U calculations
Unal, Hatice; METE, ERSEN; Ellialtıoğlu, Süleyman Şinasi (2011-09-09)
Physically reasonable electronic structures of reconstructed rutile TiO2(110)-(1x2) surfaces were studied using density functional theory (DFT) supplemented with Hubbard U on-site Coulomb repulsion acting on the d electrons, the so called DFT + U approach. Two leading reconstruction models proposed by Onishi and Iwasawa [Surf. Sci. Lett. 313, 783 (1994)] and Park and coworkers [Phys. Rev. B 75, 245415 (2007)] were compared in terms of their thermodynamic stabilities.
Design of an X-band 3-bit RF MEMS constant phase shifter
Kuzubaşlı, Ahmet; Akın, Tayfun; Demir, Şimşek; Department of Electrical and Electronics Engineering (2016)
This thesis presents a 3-bit 180° constant phase shifter design implementing Co-Planar Waveguide (CPW) and RF MEMS variable capacitors with ±1.8% accuracy at 10 GHz and ±5.8% maximum peak error between 9-11 GHz. The phase shifter with minimum phase errors is determined by considering exemplary circuit simulations of different phase shifter types designed with a novel in-house RF MEMS fabrication process [1] parameters. Due to its wide-band characteristics and CPW compatibility, the selected topology is the ...
Citation Formats
F. Yeşil, “CMOS readout electronics for mis-matched and mode-matched MEMS gyroscopes,” M.S. - Master of Science, Middle East Technical University, 2015.