This paper presents the design, fabrication, and characterization of a highly sensitive, single drive multi-axis gyroscope. The multi-axis gyroscope allows for a wide bandwidth in all three axes (X, Y, Z) and exhibits high linearity. The fabricated multi-axis gyroscope was fabricated with a structural thickness of 30 µm and packaged at 100 mtorr using wafer level packaging. The fabricated multi-axis gyroscope has a small footprint of 1426 × 1426 µm2, making it one of the smallest multi-axis gyroscopes. A custom printed circuit board (PCB) was designed for the evaluation of the multi-axis gyroscope. The experimental results demonstrate that the gyroscope has a high sensitivity of 12.56 μ V / dps , 17.13 μ V / dps and 25.79 μ V / dps in the roll (X-sense), pitch (Y-sense) and yaw (Z-sense) modes respectively. The scale-factor non-linearity of the gyroscope is less than 0.2 % for roll and pitch mode and 0.001 % for the yaw mode, in the full-scale range of ± 1500 deg / s . The multi-axis gyroscope demonstrates an angle random walk of 2.79 dps / Hz , 2.14 dps / Hz , and 1.42 dps / Hz , for the roll, pitch and yaw rate with the in-run bias stability 1.62 deg / s , 1.14 deg / s and 0.84 deg / s respectively.

https://www.mdpi.com/2072-666X/10/6/410/pdf

Single Drive Multi-Axis Gyroscope with High Dynamic Range, High Linearity and Wide Bandwidth.

A novel laterally and micro-electro-thermally actuated RF MEMS switch is presented in this paper. Despite many RF MEMS switches requiring continuous actuation voltage to hold the switch at ON-state, the proposed switch remains ON without any DC power. The mechanical design of the switch is in such a way that, the contact force of the switch is in mN range with zero DC power consumption. The switch is modeled and its operation is comprehensively analyzed. The fabrication process is completely compatible with standard MetalMUMPs process. The switch requires actuation voltages of 0.5 and 0.9 V for U-shaped and V-shaped actuators, respectively. The switch is normally OFF with isolation of ý 20 dB up to 100 GHz. The insertion loss of the switch at ON-state is better than ý 0.1 dB up to 40 GHz and the return loss is below ý 10 dB up to 100 GHz. The power consumption of the switch is confined to the transition time of the switch between OFF and ON states. Based on analytical and numerical simulations, the contact resistance of the switch is 0.028 ý. The proposed switch in this paper is dedicated for applications in mobile front-ends especially antenna switch networks where the signal loss and power consumption are the main constraints.

A low loss and power efficient micro-electro-thermally actuated RF MEMS switch for low power and low loss applications

This paper reports the design and analysis of a single drive mass three axis Microelectromechanical systems (MEMS) gyroscope. The proposed MEMS gyroscope contains a unique and simple coupling spring to couple the driving masses. Due to the use of this coupling spring, the stress effect on the spring ends is reduced as it is attached at two points with the driving mass. Moreover, the unwanted motions of the driving mass can be suppressed due to the use of the two spring beams for the support of the central spring. After FEA simulation using COMSOL Multiphysics tool, a first driving mode of the proposed design has been achieved. Other modes were achieved for the pitch, roll and yaw sensing parts. The simulated resonant frequencies are 15.20 kHz for the driving mode, 15.21 kHz for the pitch sensing mode, 15.32 kHz for the roll sensing mode and 15.59 kHz for the yaw sensing mode, respectively.

Design and analysis of a single-structure three-axis MEMS gyroscope with improved coupling spring

In this paper, a dynamic backstepping sliding mode controller with a fractional order sliding surface, which has a fuzzy boundary layer, is designed based on high-gain and disturbance observers for...

Fractional Order Fuzzy Dynamic Backstepping Sliding Mode Controller Design for Triaxial MEMS Gyroscope Based on High-gain and Disturbance Observers

The performance of microelectromechanical system (MEMS) inertial measurement units (IMUs) is susceptible to many environmental factors. Among different factors, temperature is one of the most challenging issues. This report reveals the bias stability analysis of an ovenized MEMS gyroscope. A micro-heater and a control system exploiting PID/PWM were used to compensate for the bias stability variations of a commercial MEMS IMU from BOSCH “BMI 088”. A micro-heater made of gold (Au) thin film is integrated with the commercial MEMS IMU chip. A custom-designed micro-machined glass platform thermally isolates the MEMS IMU from the ambient environment and is vacuum sealed in the leadless chip carrier (LCC) package. The BMI 088 built-in temperature sensor is used for temperature sensing of the device and the locally integrated heater. The experimental results reveal that the bias repeatability of the devices has been improved significantly to achieve the target specifications, making the commercial devices suitable for navigation. Furthermore, the effect of vacuum-packaged and non-vacuum-packaged devices was compared. It was found that the bias repeatability of vacuum-packaged devices was improved by more than 60%.

/pdf/bias-repeatability-analysis-of-vacuum-packaged-3-axis-mems-113h8oc3.pdf

Bias-Repeatability Analysis of Vacuum-Packaged 3-Axis MEMS Gyroscope Using Oven-Controlled System

In this paper a vibratory tri-axis gyroscope with single drive and three axes angular rate sense is presented. Firstly the structural design is proposed. And based on the modal analysis of this structure the operating principle of gyroscope is explained. Secondly the detail design of this gyroscope is presented. Based on simulation, the performance of the gyroscope is evaluated, the character of structural coupling among the drive and sense modes is studied. Thirdly the SOI fabrication process for this gyroscope is described. Fourthly the circuitry design including AGC and PLL is discussed, and the signal process is described in detail. Finally the implementation of this gyroscope is presented. Experiment results show the performance of the gyroscope. The scale factors are ?0.0078 V/°/s, ?0.0043 V/°/s and ?0.0049 V/°/s along X-, Y- and Z-axis respectively. And experiment results also indicate the character of structural coupling among the drive and sense modes similar with the results of simulation.

Zhang Ling

Papers

Study on a vibratory tri-axis MEMS gyroscope with single drive and multiple axes angular rate sense