High-precision microelectromechanical system(MEMS)gyroscopes are significant in many applications.Bias instability(BI)is an important parameter that indicates the performance of a MEMS gyroscope and is affected by the...High-precision microelectromechanical system(MEMS)gyroscopes are significant in many applications.Bias instability(BI)is an important parameter that indicates the performance of a MEMS gyroscope and is affected by the 1/f noise of the MEMS resonator and readout circuit.Since the bandgap reference(BGR)is an important block in the readout circuit,reducing its 1/f noise is key to improving a gyroscope's Bl.In a traditional BGR,the error amplifer is applied to provide a virtual short-circuit point,but it introduces the main low-frequency noise sources.This paper proposes an ultralow 1/f noise BGR by removing the error amplifer and applying an optimized circuit topology.In addition,a simplified but accurate noise model of the proposed BGR is obtained to optimize the BGR's output noise performance.To verify this design,the proposed BGR has been implemented in a 180 nm CMOS process with a chip area of 545×423μm.The experimental results show that the BGR's output integrated noise from 0.1 to 10 Hz is 0.82μV and the thermal noise is 35 nV/√Hz.Furthermore,bias stability tests of the MEMS gyroscope fabricated in our laboratory with the proposed BGR and some commercial BGRs are carried out.Statistical results show that reducing the BGR's 1/f noisecannearly linearly improvethegyroscope's Bl.展开更多
It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the em...It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the emitter-base junction is the main source of the base surface 1/f noise. A model is developed which identifies the parameters and describes their interactive contributions to the recombination current at the surface of the space charge region. Based on the theory of carrier number fluctuation and the model of surface recombination current, a 1/f noise model is developed. This model suggests that 1/f noise degradations are the result of the accumulation of oxide-trapped charges and interface states. Combining models of ELDRS, this model can explain the reason why the 1/f noise degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 700 Gy（Si）. The low dose rate was 0.001 Gy（Si）/s and the high dose rate was 0.1 Gy（Si）/s. The model accords well with the experimental results.展开更多
In order to restore noisy fractal Brownian motion(FBM),discrete fractional gaussiannoise(DFGN) combined with noise increments is decomposed by Haar wavelets based on Mallatalgorithm.Considering the correlation of deta...In order to restore noisy fractal Brownian motion(FBM),discrete fractional gaussiannoise(DFGN) combined with noise increments is decomposed by Haar wavelets based on Mallatalgorithm.Considering the correlation of detail coefficients,a bank of Wiener filters are used to estimatethe detail coefficients to reconstruct DFGN considering the estimated approximation coefficients in thecoarsest scale in the minimum mean square sense.Then,the reconstructed DFGN is used to restore FBM.In the digital simulation,in light of the restoration mean square error,we show that the suppose that thecorrelation of detail coefficients and the approximation coefficients in the coarsest scale for any Hurstcould be avoided is unrealistic.Moreover,we calculate the estimation root mean square error of the hurstparameter of the restored FBM to show the validity of our algorithm.展开更多
Healthy homeostasis is a principal driving force of the dynamic equilibrium of living organisms. The dynamical basis of homeostasis is the complex and interconnected feedback mechanisms, which are fundamentally govern...Healthy homeostasis is a principal driving force of the dynamic equilibrium of living organisms. The dynamical basis of homeostasis is the complex and interconnected feedback mechanisms, which are fundamentally governed by the nervous system, mainly the balance of the sympathetic and parasympathetic controlling actions. The balancing regulation is well presented in the heart’s sinus node and can be measured by the time-domain heart-rate variation (HRV) of its frequency domain to analyze the constitutional frequencies of the variation. This last is a fluctuation that shows 1/f time fractal arrangement (f is the composing frequency). The time-fractal arrangement could depend on the structural fractal of the His-Purkinje system of the heart and personally modify the HRV. The cancers gradually destroy the homeostatic harmony, starting locally and finishing systemically. The controlling activity of vagus-nerve changes the HRV or the power density spectrum of the signal fluctuations in malignant development, presenting an appropriate control of the cancerous processes. The modified spectrum by a non-invasive radiofrequency treatment could arrest the tumor growth. An appropriate modulation could support the homeostatic control and force reconstructing of the broken complexity.展开更多
Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in China's Mainland. From the experimental results and the theoretic analy...Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in China's Mainland. From the experimental results and the theoretic analysis, we realize that total dose radiation causes a lot of trapped positive charges in STI （shallow trench isolation） SiO2 layers, which induces a current leakage passage, increasing the 1/f noise power of CMOS transistors. In addition, we design some radiation-hardness structures on the CMOS transistors and the experimental results show that, until the total dose achieves 750 krad, the 1/f noise power of the radiation-hardness CMOS transistors remains unchanged, which proves our conclusion.展开更多
An integrated front-end vertical CMOS Hall magnetic sensor is proposed for the in-plane magnetic field measure-ment.To improve the magnetic sensitivity and to obtain low offset,a fully symmetric vertical Hall device(F...An integrated front-end vertical CMOS Hall magnetic sensor is proposed for the in-plane magnetic field measure-ment.To improve the magnetic sensitivity and to obtain low offset,a fully symmetric vertical Hall device(FSVHD)has been op-timized with a minimum size design.A new four-phase spinning current modulation associated with a correlated double sampling(CDS)demodulation technique has been further applied to compensate for the offset and also to provide a linear Hall output voltage.The vertical Hall sensor chip has been manufactured in a 0.18μm low-voltage CMOS technology and it occu-pies an area of 1.54 mm2.The experimental results show in the magnetic field range from-200 to 200 mT,the entire vertical Hall sensor performs with the linearity of 99.9%and the system magnetic sensitivity of 1.22 V/T and the residual offset of 60μT.Meanwhile,it consumes 4.5 mW at a 3.3 V supply voltage.The proposed vertical Hall sensor is very suitable for the low-cost sys-tem-on-chip(SOC)implementation of 2D or 3D magnetic microsystems.展开更多
This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electron...This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit,which is a silicon nanowire and a Continuous-Time(CT)△∑ADC.The first integrator of the△∑ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise operations.To mitigate both the offset and 1/f noise,a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator.A 65-nm CMOS process implements the CT△∑ADC.The supply voltage of the CMOS circuit is 1.2-V while 0.96-mW is the power consumption and 0.1-mm^(2) is the silicon area.The M&NEMS microphone and△∑ADC complete circuit are fabricated and measured.Over a working frequency bandwidth of 20-kHz,the measurement results of the proposed IoT system reach a signal to noise ratio(SNR)of 102.8-dB.Moreover,it has a measured dynamic range(DR)of 108-dB and a measured signal to noise and distortion ratio(SNDR)of 101.3-dB.展开更多
The representation of 1/f signal with wavelet transformation is explored. It is shown that a class of 1/f signal can be represented via wavelet synthetic formula and that a statistically self-similar property of signa...The representation of 1/f signal with wavelet transformation is explored. It is shown that a class of 1/f signal can be represented via wavelet synthetic formula and that a statistically self-similar property of signals may be characterized by the correlation functions of wavelet coefficients in the wavelet domain.展开更多
In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuati...In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuation in a two- dimensional electron gas （2DEG） channel of AlGaN/GaN HEMT, a unified drain current 1/f noise model containing a piezoelectric polarization effect and hot carrier effect is built. The drain current 1/f noise induced by the piezoelectric polarization effect is distinguished from that induced by the hot carrier effect through experiments and simulations. The simulation results are in good agreement with the experimental results. Experiments show that after hot carrier injection, the drain current 1/f noise increases four orders of magnitude and the electrical parameter degradation Agm/gm reaches 54.9%. The drain current 1/f noise degradation induced by the piezoelectric effect reaches one order of magnitude; the electrical parameter degradation Agm/gm is 11.8%. This indicates that drain current 1/f noise of the GaN-based HEMT device is sensitive to the hot carrier effect and piezoelectric effect. This study provides a useful reliability characterization tool for the A1GaN/GaN HEMTs.展开更多
SINCE Jin et al. discovered the surprising giant magnetoresistance （GMR） effects in oxide films, the GMR oxide materials have attracted much attention. The cause of the GMR effects has been understood on the basis o...SINCE Jin et al. discovered the surprising giant magnetoresistance （GMR） effects in oxide films, the GMR oxide materials have attracted much attention. The cause of the GMR effects has been understood on the basis of mixed valences of manganese ion. Therefore, pairs of Mn<sup>3+</sup> and Mn<sup>4+</sup> can be controlled by oxygen behavior, which affects the magnetic and electnc properties of those materials. Some researchers have experimentally shown that展开更多
After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrela...After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrelating 1/f noise using the wavelet transform and deduces the relative expressions. The results of computer simulation show good effectiveness.展开更多
Radiation-induced 1/f noise degradation in the LM117 bipolar linear voltage regulator is studied. Based on the radiation-induced degradation mechanism of the output voltage, it is suggested that the band-gap reference...Radiation-induced 1/f noise degradation in the LM117 bipolar linear voltage regulator is studied. Based on the radiation-induced degradation mechanism of the output voltage, it is suggested that the band-gap reference subcircuit is the critical component which leads to the 1/f noise degradation of the LM117. The radiation makes the base surface current of the bipolar junction transistors of the band-gap reference subcircuit increase, which leads to an increase in the output 1/f noise of the LM117. Compared to the output voltage, the 1/f noise parameter is more sensitive, it may be used to evaluate the radiation resistance capability of LM117.展开更多
The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the squ...The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the square of the bias voltage. With decreasing temperature the noise level also decreases. At 4.2 K the noise level follows a non-monotonic dependence against the bias voltage, showing a peak at a certain bias voltage, meanwhile its frequency dependence also deviates from the 1/f trend. This anomalous behaviour is discussed within the picture of environmental quantum fluctuation of charge transport in the samples.展开更多
基金support from the National Natural Science Foundation of China under grant No.92164203.
文摘High-precision microelectromechanical system(MEMS)gyroscopes are significant in many applications.Bias instability(BI)is an important parameter that indicates the performance of a MEMS gyroscope and is affected by the 1/f noise of the MEMS resonator and readout circuit.Since the bandgap reference(BGR)is an important block in the readout circuit,reducing its 1/f noise is key to improving a gyroscope's Bl.In a traditional BGR,the error amplifer is applied to provide a virtual short-circuit point,but it introduces the main low-frequency noise sources.This paper proposes an ultralow 1/f noise BGR by removing the error amplifer and applying an optimized circuit topology.In addition,a simplified but accurate noise model of the proposed BGR is obtained to optimize the BGR's output noise performance.To verify this design,the proposed BGR has been implemented in a 180 nm CMOS process with a chip area of 545×423μm.The experimental results show that the BGR's output integrated noise from 0.1 to 10 Hz is 0.82μV and the thermal noise is 35 nV/√Hz.Furthermore,bias stability tests of the MEMS gyroscope fabricated in our laboratory with the proposed BGR and some commercial BGRs are carried out.Statistical results show that reducing the BGR's 1/f noisecannearly linearly improvethegyroscope's Bl.
基金supported by the National Natural Science Foundation of China(Grant Nos.61076101 and 61204092)
文摘It is found that ionizing-radiation can lead to the base current and the 1/f noise degradations in PNP bipolar junction transistors. In this paper, it is suggested that the surface of the space charge region of the emitter-base junction is the main source of the base surface 1/f noise. A model is developed which identifies the parameters and describes their interactive contributions to the recombination current at the surface of the space charge region. Based on the theory of carrier number fluctuation and the model of surface recombination current, a 1/f noise model is developed. This model suggests that 1/f noise degradations are the result of the accumulation of oxide-trapped charges and interface states. Combining models of ELDRS, this model can explain the reason why the 1/f noise degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 700 Gy（Si）. The low dose rate was 0.001 Gy（Si）/s and the high dose rate was 0.1 Gy（Si）/s. The model accords well with the experimental results.
文摘In order to restore noisy fractal Brownian motion(FBM),discrete fractional gaussiannoise(DFGN) combined with noise increments is decomposed by Haar wavelets based on Mallatalgorithm.Considering the correlation of detail coefficients,a bank of Wiener filters are used to estimatethe detail coefficients to reconstruct DFGN considering the estimated approximation coefficients in thecoarsest scale in the minimum mean square sense.Then,the reconstructed DFGN is used to restore FBM.In the digital simulation,in light of the restoration mean square error,we show that the suppose that thecorrelation of detail coefficients and the approximation coefficients in the coarsest scale for any Hurstcould be avoided is unrealistic.Moreover,we calculate the estimation root mean square error of the hurstparameter of the restored FBM to show the validity of our algorithm.
文摘Healthy homeostasis is a principal driving force of the dynamic equilibrium of living organisms. The dynamical basis of homeostasis is the complex and interconnected feedback mechanisms, which are fundamentally governed by the nervous system, mainly the balance of the sympathetic and parasympathetic controlling actions. The balancing regulation is well presented in the heart’s sinus node and can be measured by the time-domain heart-rate variation (HRV) of its frequency domain to analyze the constitutional frequencies of the variation. This last is a fluctuation that shows 1/f time fractal arrangement (f is the composing frequency). The time-fractal arrangement could depend on the structural fractal of the His-Purkinje system of the heart and personally modify the HRV. The cancers gradually destroy the homeostatic harmony, starting locally and finishing systemically. The controlling activity of vagus-nerve changes the HRV or the power density spectrum of the signal fluctuations in malignant development, presenting an appropriate control of the cancerous processes. The modified spectrum by a non-invasive radiofrequency treatment could arrest the tumor growth. An appropriate modulation could support the homeostatic control and force reconstructing of the broken complexity.
基金Project supported by the National Key Laboratory Foundations(No.9140C090402110C0906)
文摘Using 0.18 μm CMOS transistors, the total dose effects on the 1/f noise of deep-submicron CMOS transistors are studied for the first time in China's Mainland. From the experimental results and the theoretic analysis, we realize that total dose radiation causes a lot of trapped positive charges in STI （shallow trench isolation） SiO2 layers, which induces a current leakage passage, increasing the 1/f noise power of CMOS transistors. In addition, we design some radiation-hardness structures on the CMOS transistors and the experimental results show that, until the total dose achieves 750 krad, the 1/f noise power of the radiation-hardness CMOS transistors remains unchanged, which proves our conclusion.
基金the National Natural Science Foundation of China(Nos.61871231,62171233)the Natural Science Foundation of Jiangsu Province,China(No.BK20181390)+1 种基金the Key Research&Development Plan of Jiangsu Province,China(No.BE2019741)the Agricultural Science and Technology Independent Innovation Foundation of Jiangsu Province,China(No.CX(21)3062).
文摘An integrated front-end vertical CMOS Hall magnetic sensor is proposed for the in-plane magnetic field measure-ment.To improve the magnetic sensitivity and to obtain low offset,a fully symmetric vertical Hall device(FSVHD)has been op-timized with a minimum size design.A new four-phase spinning current modulation associated with a correlated double sampling(CDS)demodulation technique has been further applied to compensate for the offset and also to provide a linear Hall output voltage.The vertical Hall sensor chip has been manufactured in a 0.18μm low-voltage CMOS technology and it occu-pies an area of 1.54 mm2.The experimental results show in the magnetic field range from-200 to 200 mT,the entire vertical Hall sensor performs with the linearity of 99.9%and the system magnetic sensitivity of 1.22 V/T and the residual offset of 60μT.Meanwhile,it consumes 4.5 mW at a 3.3 V supply voltage.The proposed vertical Hall sensor is very suitable for the low-cost sys-tem-on-chip(SOC)implementation of 2D or 3D magnetic microsystems.
文摘This paper presents a proposed low-noise and high-sensitivity Internet of Thing(IoT)system based on an M&NEMS microphone.The IoT device consists of an M&NEMS resistive accelerometer associated with an electronic readout circuit,which is a silicon nanowire and a Continuous-Time(CT)△∑ADC.The first integrator of the△∑ADC is based on a positive feedback DC-gain enhancement two-stage amplifier due to its high linearity and low-noise operations.To mitigate both the offset and 1/f noise,a suggested delay-time chopper negative-R stabilization technique is applied around the first integrator.A 65-nm CMOS process implements the CT△∑ADC.The supply voltage of the CMOS circuit is 1.2-V while 0.96-mW is the power consumption and 0.1-mm^(2) is the silicon area.The M&NEMS microphone and△∑ADC complete circuit are fabricated and measured.Over a working frequency bandwidth of 20-kHz,the measurement results of the proposed IoT system reach a signal to noise ratio(SNR)of 102.8-dB.Moreover,it has a measured dynamic range(DR)of 108-dB and a measured signal to noise and distortion ratio(SNDR)of 101.3-dB.
文摘The representation of 1/f signal with wavelet transformation is explored. It is shown that a class of 1/f signal can be represented via wavelet synthetic formula and that a statistically self-similar property of signals may be characterized by the correlation functions of wavelet coefficients in the wavelet domain.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61076101,61204092,61334002,and JJ0500102508)
文摘In this work, we present a theoretical and experimental study on the drain current 1/f noise in the AIGaN/GaN high electron mobility transistor （HEMT）. Based on both mobility fluctuation and carrier number fluctuation in a two- dimensional electron gas （2DEG） channel of AlGaN/GaN HEMT, a unified drain current 1/f noise model containing a piezoelectric polarization effect and hot carrier effect is built. The drain current 1/f noise induced by the piezoelectric polarization effect is distinguished from that induced by the hot carrier effect through experiments and simulations. The simulation results are in good agreement with the experimental results. Experiments show that after hot carrier injection, the drain current 1/f noise increases four orders of magnitude and the electrical parameter degradation Agm/gm reaches 54.9%. The drain current 1/f noise degradation induced by the piezoelectric effect reaches one order of magnitude; the electrical parameter degradation Agm/gm is 11.8%. This indicates that drain current 1/f noise of the GaN-based HEMT device is sensitive to the hot carrier effect and piezoelectric effect. This study provides a useful reliability characterization tool for the A1GaN/GaN HEMTs.
文摘SINCE Jin et al. discovered the surprising giant magnetoresistance （GMR） effects in oxide films, the GMR oxide materials have attracted much attention. The cause of the GMR effects has been understood on the basis of mixed valences of manganese ion. Therefore, pairs of Mn<sup>3+</sup> and Mn<sup>4+</sup> can be controlled by oxygen behavior, which affects the magnetic and electnc properties of those materials. Some researchers have experimentally shown that
文摘After briefly introducing the characteristics of 1/f noise in millimeter wave focalplane array detectors, the paper analyses the relation of wavelet transform and 1/f noise in detail, suggests the fashion of decorrelating 1/f noise using the wavelet transform and deduces the relative expressions. The results of computer simulation show good effectiveness.
基金Project supported by the National Natural Science Foundation of China(Nos.61076101,61204092)
文摘Radiation-induced 1/f noise degradation in the LM117 bipolar linear voltage regulator is studied. Based on the radiation-induced degradation mechanism of the output voltage, it is suggested that the band-gap reference subcircuit is the critical component which leads to the 1/f noise degradation of the LM117. The radiation makes the base surface current of the bipolar junction transistors of the band-gap reference subcircuit increase, which leads to an increase in the output 1/f noise of the LM117. Compared to the output voltage, the 1/f noise parameter is more sensitive, it may be used to evaluate the radiation resistance capability of LM117.
文摘The 1/f noise in multiwalled carbon nanotubes bundles has been investigated between the frequency range of 0.1 to 30 Hz. At room temperature the noise spectrum is standard 1/f, and its level is proportional to the square of the bias voltage. With decreasing temperature the noise level also decreases. At 4.2 K the noise level follows a non-monotonic dependence against the bias voltage, showing a peak at a certain bias voltage, meanwhile its frequency dependence also deviates from the 1/f trend. This anomalous behaviour is discussed within the picture of environmental quantum fluctuation of charge transport in the samples.
