In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock...In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application.展开更多
Lock-in amplifiers are used to detect and measure very small alternating current(AC)signals down to the range of nVs.Accurate measurements can be made even when the small signals are buried by noise thousands of times...Lock-in amplifiers are used to detect and measure very small alternating current(AC)signals down to the range of nVs.Accurate measurements can be made even when the small signals are buried by noise thousands of times larger.With the digital signal processing(DSP)technology involved in modern instrumentation,a lock-in amplifier is more versatile in sensing and recovering small signals.Combining the virtual instrumentation technology,we reorganize the functional blocks of a programmable lock-in amplifier and build it as a virtual spectrum analyzer,virtual impedance meter,virtual network analyzer,virtual semiconductor parameter analyzer,signal generator,etc.A 4 layer model is used to implement these virtual instruments.The same virtual instrument can also be implemented on a general purpose FPGA developing board.展开更多
A method of implementing high cost-effective and highly integrated digital lock-in amplifier with microcontroller is discussed. And the digital lock-in amplifier is more suitable for meastwing lowfrequency weak signal...A method of implementing high cost-effective and highly integrated digital lock-in amplifier with microcontroller is discussed. And the digital lock-in amplifier is more suitable for meastwing lowfrequency weak signal. Digital signal sequence is obtained through sampling signal measured over an integer number of signal periods, but digital reference sequence is acquired through mathematical operation, then digital phase sensitive detection can be implemented by calculating the cross-correlation function of digital signal sequence and digital reference sequence. In addition, the frequency response and phase character of the digital lock-in amplifier is analyzed. Finally, the designed digital lock-in amplifier is achieved. Expermental results show that the digital lock-in amplifier can be used for measuring weak signal with low ignal-to-noise ratio.展开更多
A limiting amplifier (LA) IC implemented in TSMC standard 0.25μm CMOS technology is described.Active inductor loads and direct-coupled technology are employed to increase the gain,broaden the bandwidth,reduce the pow...A limiting amplifier (LA) IC implemented in TSMC standard 0.25μm CMOS technology is described.Active inductor loads and direct-coupled technology are employed to increase the gain,broaden the bandwidth,reduce the power dissipation,and keep a tolerable noise performance.Under a 3.3V supply voltage,the LA core achieves a gain of 50-dB with a power consumption below 40mW.The measured input sensitivity of the amplifier is better than 5m V _ pp .It can operate at bit rates up to 7Gb/s with an rms jitter of 0.03 UI or less.The chip area is only 0.70mm×0.70mm.According to the measurement results,this IC is expected to work at the standard bit rate levels of 2.5,3.125,and 5Gb/s.展开更多
The appearance of third-generation semiconductors represented by gallium nitride (GaN) material greatly improves the output power of a power amplifier (PA), but the efficiency of the PA needs to be further improve...The appearance of third-generation semiconductors represented by gallium nitride (GaN) material greatly improves the output power of a power amplifier (PA), but the efficiency of the PA needs to be further improved. The Class-F PA reduces the overlap of drain voltage and current by tuning harmonic impedance so that high efficiency is achieved. This paper begins with the principle of class-F PA, regards the third harmonic voltage as an independent variable, analyzes the influence of the third harmonic on fundamental, and points out how drain efficiency and output power vary with the third harmonic voltage with an I-V knee effect. Finally, the best third harmonic impedance is found mathematically. We compare our results with the Loadpull technique in advanced design system environment and conclude that an optimized third harmonic impedance is open in an ideal case, while it is not at an open point with the I-V knee effect, and the drain efficiency with optimized third harmonic impedance is 4% higher than that with the third harmonic open.展开更多
Introducing a System-on-Chip (SoC) microcontroller (C8051F350) into a ceramic pressure sensor has resulted in the design of a intelligent sensor. An improved algorithm for digital phassensitive detection is used ...Introducing a System-on-Chip (SoC) microcontroller (C8051F350) into a ceramic pressure sensor has resulted in the design of a intelligent sensor. An improved algorithm for digital phassensitive detection is used to perform lock-in amplification of the sensor signal. The compensation for the sensor error is realized by the detection of the sensor's supply voltage and working temperature. The system also has the function of short/open circuit fault detection and can ommamicate with other digital equipment through an RS-485 communication interface. In the design, full utilization of the SoC microcontroller' s internal resource results in the simple hardware structure. Experimental results show that the error of the sensor is less than 0.5% at range ratio 1 : 10. Employing the microcontroller and using lock-in amplification algorithm are an effective method for achieving an intelligent sensor of slowly-varying physical quantities, thereby improving the measuring accuracy and performance.展开更多
In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed i...In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.展开更多
Coherent beam combination of two W-level fiber amplifiers with multi-dithering technique is demonstrated.In the experiment,the master laser is split into two channels.Multi-dithering technique is used for phase contro...Coherent beam combination of two W-level fiber amplifiers with multi-dithering technique is demonstrated.In the experiment,the master laser is split into two channels.Multi-dithering technique is used for phase control.One channel is modulated with a 100 kHz sine wave produced by signal generator,and DSP lock-in amplifier is used for electric signal processing in the feedback loop.When the phase control loop is off,the far field interference pattern is blurred and dynamic with 20% fringe contrast.When the f...展开更多
The resonator integrated optic gyros(RIOGs) based on the Sagnac effect have gained extensive attention in navigation and guidance systems due to their predominant advantages: high theoretical accuracy and simple in...The resonator integrated optic gyros(RIOGs) based on the Sagnac effect have gained extensive attention in navigation and guidance systems due to their predominant advantages: high theoretical accuracy and simple integration. However, the problems of losing lock and low lock-in accuracy are the bottlenecks, which restrict the development of digital RIOGs. Therefore, a multilevel laser frequency lock-in technique has been proposed in this Letter to address these problems. The experimental results show that lock-in accuracy can be improved one order higher and without losing lock in a variable temperature environment. Then, a digital miniaturized RIOG prototype(18 cm × 18 cm × 20 cm) has been produced, and long-term(1 h) bias stability of 26.6 deg/h is successfully demonstrated.展开更多
A portable analog lock-in amplifier capable of accurate phase detection is proposed in this paper. The proposed lock-in amplifier, which uses the dual-channel orthometric signals as the references to build the xy coor...A portable analog lock-in amplifier capable of accurate phase detection is proposed in this paper. The proposed lock-in amplifier, which uses the dual-channel orthometric signals as the references to build the xy coordinate system, can detect the relative phase between the input and x-axis based on trigonometric function. The sensitivity of the phase measurement reaches 0.014degree, and a detection precision of 0.1 degree is achieved. At the same time, the performance of the lock-in amplifier is verified in the high precision optical oxygen concentration detection. Experimental results reveal that the portable analog lock-in amplifier is accurate for phase detection applications. In the oxygen sensing experiments, 0.058% oxygen concentration resulted in 0.1 degree phase shift detected by the lock-in amplifier precisely. In addition, the lock-in amplifier is small and economical compared with the commercial lock-in equipments, so it can be easily integrated in many portable devices for industrial applications.展开更多
基金The National Natural Science Foundation ofChina(No.60402003)The National High Technology Research and Development Pro-gram of China(863Program)(No.2002AA745120)
文摘In the novel prototype of micro-gyroscope structure,the new configured capacitance sensing scheme for the micro gyroscope was analyzed and the virtual instrument based detection scheme was implemented.The digital lock-in amplifier was employed in the capacitance detection to restrain the noise interference.The capacitance analysis shows that 1 fF capacitance variation corresponds to 0.1 degree of the turn angle.The differential capacitance bridge and the charge integral amplifier were used as the front signal input interface.In the implementation of digital lock-in amplifier,a new routine which warranted the exactly matching of the reference phase to signal phase was proposed.The result of the experiment shows that digital lock-in amplifier can greatly eliminate the noise in the output signal.The non linearity of the turn angle output is 2.3% and the minimum resolution of turn angle is 0.04 degrees.The application of the software demodulation in the signal detection of micro-electro-mechanical-system(MEMS)device is a new attempt,and it shows the prospective for a high-performance application.
文摘Lock-in amplifiers are used to detect and measure very small alternating current(AC)signals down to the range of nVs.Accurate measurements can be made even when the small signals are buried by noise thousands of times larger.With the digital signal processing(DSP)technology involved in modern instrumentation,a lock-in amplifier is more versatile in sensing and recovering small signals.Combining the virtual instrumentation technology,we reorganize the functional blocks of a programmable lock-in amplifier and build it as a virtual spectrum analyzer,virtual impedance meter,virtual network analyzer,virtual semiconductor parameter analyzer,signal generator,etc.A 4 layer model is used to implement these virtual instruments.The same virtual instrument can also be implemented on a general purpose FPGA developing board.
文摘A method of implementing high cost-effective and highly integrated digital lock-in amplifier with microcontroller is discussed. And the digital lock-in amplifier is more suitable for meastwing lowfrequency weak signal. Digital signal sequence is obtained through sampling signal measured over an integer number of signal periods, but digital reference sequence is acquired through mathematical operation, then digital phase sensitive detection can be implemented by calculating the cross-correlation function of digital signal sequence and digital reference sequence. In addition, the frequency response and phase character of the digital lock-in amplifier is analyzed. Finally, the designed digital lock-in amplifier is achieved. Expermental results show that the digital lock-in amplifier can be used for measuring weak signal with low ignal-to-noise ratio.
文摘A limiting amplifier (LA) IC implemented in TSMC standard 0.25μm CMOS technology is described.Active inductor loads and direct-coupled technology are employed to increase the gain,broaden the bandwidth,reduce the power dissipation,and keep a tolerable noise performance.Under a 3.3V supply voltage,the LA core achieves a gain of 50-dB with a power consumption below 40mW.The measured input sensitivity of the amplifier is better than 5m V _ pp .It can operate at bit rates up to 7Gb/s with an rms jitter of 0.03 UI or less.The chip area is only 0.70mm×0.70mm.According to the measurement results,this IC is expected to work at the standard bit rate levels of 2.5,3.125,and 5Gb/s.
文摘The appearance of third-generation semiconductors represented by gallium nitride (GaN) material greatly improves the output power of a power amplifier (PA), but the efficiency of the PA needs to be further improved. The Class-F PA reduces the overlap of drain voltage and current by tuning harmonic impedance so that high efficiency is achieved. This paper begins with the principle of class-F PA, regards the third harmonic voltage as an independent variable, analyzes the influence of the third harmonic on fundamental, and points out how drain efficiency and output power vary with the third harmonic voltage with an I-V knee effect. Finally, the best third harmonic impedance is found mathematically. We compare our results with the Loadpull technique in advanced design system environment and conclude that an optimized third harmonic impedance is open in an ideal case, while it is not at an open point with the I-V knee effect, and the drain efficiency with optimized third harmonic impedance is 4% higher than that with the third harmonic open.
基金supported by Research Project of "SUSTSpring Bud"(No.2008BWZ042)from Shandong University of Science and Technology
文摘Introducing a System-on-Chip (SoC) microcontroller (C8051F350) into a ceramic pressure sensor has resulted in the design of a intelligent sensor. An improved algorithm for digital phassensitive detection is used to perform lock-in amplification of the sensor signal. The compensation for the sensor error is realized by the detection of the sensor's supply voltage and working temperature. The system also has the function of short/open circuit fault detection and can ommamicate with other digital equipment through an RS-485 communication interface. In the design, full utilization of the SoC microcontroller' s internal resource results in the simple hardware structure. Experimental results show that the error of the sensor is less than 0.5% at range ratio 1 : 10. Employing the microcontroller and using lock-in amplification algorithm are an effective method for achieving an intelligent sensor of slowly-varying physical quantities, thereby improving the measuring accuracy and performance.
文摘In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.
文摘Coherent beam combination of two W-level fiber amplifiers with multi-dithering technique is demonstrated.In the experiment,the master laser is split into two channels.Multi-dithering technique is used for phase control.One channel is modulated with a 100 kHz sine wave produced by signal generator,and DSP lock-in amplifier is used for electric signal processing in the feedback loop.When the phase control loop is off,the far field interference pattern is blurred and dynamic with 20% fringe contrast.When the f...
基金supported by the National Natural Science Foundation of China(Nos.51635011,61640601,61571406,and 51727808)the Outstanding Youth Talents Program of Shanxi Province(No.2016002)+1 种基金the Science and Technology on Electronic Test&Measurement Laboratory(No.11010311)the Shanxi "1331 KSC"
文摘The resonator integrated optic gyros(RIOGs) based on the Sagnac effect have gained extensive attention in navigation and guidance systems due to their predominant advantages: high theoretical accuracy and simple integration. However, the problems of losing lock and low lock-in accuracy are the bottlenecks, which restrict the development of digital RIOGs. Therefore, a multilevel laser frequency lock-in technique has been proposed in this Letter to address these problems. The experimental results show that lock-in accuracy can be improved one order higher and without losing lock in a variable temperature environment. Then, a digital miniaturized RIOG prototype(18 cm × 18 cm × 20 cm) has been produced, and long-term(1 h) bias stability of 26.6 deg/h is successfully demonstrated.
文摘A portable analog lock-in amplifier capable of accurate phase detection is proposed in this paper. The proposed lock-in amplifier, which uses the dual-channel orthometric signals as the references to build the xy coordinate system, can detect the relative phase between the input and x-axis based on trigonometric function. The sensitivity of the phase measurement reaches 0.014degree, and a detection precision of 0.1 degree is achieved. At the same time, the performance of the lock-in amplifier is verified in the high precision optical oxygen concentration detection. Experimental results reveal that the portable analog lock-in amplifier is accurate for phase detection applications. In the oxygen sensing experiments, 0.058% oxygen concentration resulted in 0.1 degree phase shift detected by the lock-in amplifier precisely. In addition, the lock-in amplifier is small and economical compared with the commercial lock-in equipments, so it can be easily integrated in many portable devices for industrial applications.