High-Q integrated spiral inductors for high performance wireless front-end systems

Author(s):  
P. Pieters ◽  
K. Vaesen ◽  
W. Diels ◽  
G. Carchon ◽  
S. Brebels ◽  
...  
Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 675 ◽  
Author(s):  
Xiangyu Li ◽  
Jianping Hu ◽  
Xiaowei Liu

Micro-electromechanical system (MEMS) accelerometers are widely used in the inertial navigation and nanosatellites field. A high-performance digital interface circuit for a high-Q MEMS micro-accelerometer is presented in this work. The mechanical noise of the MEMS accelerometer is decreased by the application of a vacuum-packaged sensitive element. The quantization noise in the baseband of the interface circuit is greatly suppressed by a 4th-order loop shaping. The digital output is attained by the interface circuit based on a low-noise front-end charge-amplifier and a 4th-order Sigma-Delta (ΣΔ) modulator. The stability of high-order ΣΔ was studied by the root locus method. The gain of the integrators was reduced by using the proportional scaling technique. The low-noise front-end detection circuit was proposed with the correlated double sampling (CDS) technique to eliminate the 1/f noise and offset. The digital interface circuit was implemented by 0.35 μm complementary metal-oxide-semiconductor (CMOS) technology. The high-performance digital accelerometer system was implemented by double chip integration and the active interface circuit area was about 3.3 mm × 3.5 mm. The high-Q MEMS accelerometer system consumed 10 mW from a single 5 V supply at a sampling frequency of 250 kHz. The micro-accelerometer system could achieve a third harmonic distortion of −98 dB and an average noise floor in low-frequency range of less than −140 dBV; a resolution of 0.48 μg/Hz1/2 (@300 Hz); a bias stability of 18 μg by the Allen variance program in MATLAB.


Author(s):  
Heng-Ming Hsu ◽  
Jiong-Guang Su ◽  
Yo-Sheng Lin ◽  
Ming-Hao Tseng ◽  
Jason Chih-Hsien Lin ◽  
...  

Author(s):  
Harold O. Fried ◽  
Loren W. Tauer

This article explores how well an individual manages his or her own talent to achieve high performance in an individual sport. Its setting is the Ladies Professional Golf Association (LPGA). The order-m approach is explained. Additionally, the data and the empirical findings are presented. The inputs measure fundamental golfing athletic ability. The output measures success on the LPGA tour. The correlation coefficient between earnings per event and the ability to perform under pressure is 0.48. The careers of golfers occur on the front end of the age distribution. There is a classic trade-off between the inevitable deterioration in the mental ability to handle the pressure and experience gained with time. The ability to perform under pressure peaks at age 37.


2018 ◽  
Vol 23 (3) ◽  
pp. 305-318
Author(s):  
Yinglu Zhang ◽  
Zhenzhu Xi ◽  
Xingpeng Chen ◽  
Honglan Wei ◽  
Long Huang ◽  
...  

High-performance audio-frequency magnetotelluric (AMT) instrument is one means of obtaining high-quality electromagnetic (EM) data. To improve the ability of AMT system to obtain high-quality data, this paper presents a design for a high-performance analog front-end circuit for AMT instrument. It mainly consists of the input protection, preamplifier, passive high pass filter, power frequency notch filter, programmable amplifier, and active low pass filter. In addition, this paper proposes a design of low-noise, high-performance preamplifier, which improves the common-mode rejection ratio (CMRR) of analog front-end circuit and effectively enhances the signal-to-noise ratio (SNR) of the circuit. The front-end circuit utilized two-stage twin-T notch filter to effectively suppress the strong interference of fundamental component of power frequency. Also, it used signal relays to control circuit gain and selection of cutoff frequency of anti-aliasing filter, resulting in the improvement of the capability of the analog-to-digital Converter (ADC) to distinguish weak EM signal. The measured results of the electric field and magnetic field channel showed that: 1) The circuit works in frequency range of 1 Hz∼100 kHz; 2) The CMRR values of the preamplifier of electric field channel at low frequencies (1 Hz∼1 kHz) are 111 dB and 97 dB when the gains are 20 dB and 6 dB respectively; 3) The maximum attenuation fundamental power frequency can reach −39.46 dB and −39.04 dB respectively; 4) The total harmonic distortion rate at 1 kHz is 0.022% and 0.029% respectively; 5) The input noise levels of electric field channel are 12.67nV / [Formula: see text] @10Hz and 8.15V / [Formula: see text] @1kHz, while the input noise levels of magnetic field channel are 8.97nV / [Formula: see text] @10Hz and 6.16V / [Formula: see text] @1kHz; and 6) In conclusion, the analog front-end circuit is superior to meet the requirements of the AMT methods, and provides a useful reference for the development of AMT instrument.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1071
Author(s):  
Bo Jiang ◽  
Yan Su ◽  
Guowen Liu ◽  
Lemin Zhang ◽  
Fumin Liu

Disc gyroscope manufactured through microelectromechanical systems (MEMS) fabrication processes becomes one of the most critical solutions for achieving high performance. Some reported novel disc constructions acquire good performance in bias instability, scale factor nonlinearity, etc. However, antivibration characteristics are also important for the devices, especially in engineering applications. For multi-ring structures with central anchors, the out-of-plane motions are in the first few modes, easily excited within the vibration environment. The paper presents a multi-ring gyro with good dynamic characteristics, operating at the first resonant mode. The design helps obtain better static performance and antivibration characteristics with anchor points outside of the multi-ring resonator. According to harmonic experiments, the nearest interference mode is located at 30,311 Hz, whose frequency difference is 72.8% far away from working modes. The structures were fabricated with silicon on insulator (SOI) processes and wafer-level vacuum packaging, where the asymmetry is 780 ppm as the frequency splits. The gyro also obtains a high Q-factor. The measured value at 0.15 Pa was 162 k, which makes the structure have sizeable mechanical sensitivity and low noise.


Sign in / Sign up

Export Citation Format

Share Document