A monolithic integrated CMOS preamplifier is presented for neural recording applications. Two AC-coupied capacitors are used to eliminate the large and random DC offsets existing in the electrode-electrolyte interface...A monolithic integrated CMOS preamplifier is presented for neural recording applications. Two AC-coupied capacitors are used to eliminate the large and random DC offsets existing in the electrode-electrolyte interface. Diode-connected nMOS transistors with a negative voltage between the gate and source are candidates for the large resistors necessary for the preamplifier. A novel analysis is given to determine the noise power spectral density. Simulation results show that the two-stage CMOS preamplifier in a closed-loop capacitive feedback configuration provides an AC in-band gain of 38.8dB,a DC gain of 0,and an input-referred noise of 277nVmax, integrated from 0. 1Hz to 1kHz. The preamplifier can eliminate the DC offset voltage and has low input-referred noise by novel circuit configuration and theoretical analysis.展开更多
A high gain cascade connected preamplifier for optical receivers is developed with 0.5μm GaAs PHEMT technology from the Nanjing Electronic Devices Institute. To begin with, the transimpedance amplifier has a -3dB ban...A high gain cascade connected preamplifier for optical receivers is developed with 0.5μm GaAs PHEMT technology from the Nanjing Electronic Devices Institute. To begin with, the transimpedance amplifier has a -3dB bandwidth of 10GHz, with a small signal gain of around 9dB. The post-stage distributed amplifier （DA） has a -3dB bandwidth of close to 20GHz,with a small signal gain of around 12dB. As a whole,the cascade preamplifier has a measured small signal gain of 21.3dB and a transimpedance of 55.3dBΩ in a 50Ω system. With a higher signal-to-noise ratio than that of the TIA and a markedly improved waveform distortion compared with that of the DA, the measured output eye diagram for 10Gb/s NRZ pseudorandom binary sequence is clear and symmetric.展开更多
A single power supply common-gate （CG） current mode transimpedance preamplifier （TIA） is developed with a 0.5μm GaAs PHEMT process. The amplifier has a measured - 3dB bandwidth of 7. 5GHz and a transimpedance gai...A single power supply common-gate （CG） current mode transimpedance preamplifier （TIA） is developed with a 0.5μm GaAs PHEMT process. The amplifier has a measured - 3dB bandwidth of 7. 5GHz and a transimpedance gain of 45dBΩ. Both the input and output voltage standing wave ratios （VSWR） are less than 2 within the bandwidth. The equivalent input noise current spectral density varies from 14.3 to 22pA/√Hz, with an average value of 17. 2pA/√Hz. Having a timing jitter of 14ps and eye amplitude of about 138mV,the measured output eye diagram for 10Gb/s NRZ pseudorandom binary sequence （PRBS） is clear and satisfactory.展开更多
A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to pe...A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to perform auto-gaincontrol and threshold extraction. Regulated cascade （RGC） architecture is exploited as the input stage to reduce the input impedance of the circuit and isolate the large parasitic capacitance including the photodiode capacitance from the determination pole, thus increasing the bandwidth. This preamplifier is implemented using the low-cost 0. 13 ixm CMOS technology. The die area is 425 μm × 475 μm and the total power dissipation is 23.4 mW. The test results indicate that the preamplifier can work at a speed from 1.25 to 10.312 5 Gbit/s, providing a high transimpedance gain of 64.0 dBΩ and a low gain of 54. 6 dBl2 with a dynamic input range of over 22.9 dB. The equivalent input noise current is 23. 4 pA/ Hz1/2. The proposed burst amplifier satisfies related specifications defined in 10G-EPON and XG-PON standards.展开更多
A new probe for atmospheric electric field mill is introduced.It consists of three parts：signal acquisition circuit for atmospheric electric field,preamplifier circuit and phase sensitive detection circuit.The signal...A new probe for atmospheric electric field mill is introduced.It consists of three parts：signal acquisition circuit for atmospheric electric field,preamplifier circuit and phase sensitive detection circuit.The signal acquisition circuit adopts the double-stator structure to form differential input circuit,thus double-precision is obtained.Preamplifier circuit is made of current-to-voltage （I-V） conversion circuit,differential amplifier circtuit and secondary amplifying circuit.The polarity of electric field is obtained via phase sensitive detection circuit.Simulation results are obtained using Multisim,and the feasibility of the designed probe is verified.展开更多
RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques. Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryl...RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques. Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryless predistortion cannot linearize PAs effectively. After analyzing PA memory effects, a novel predistortion method based on wavelet networks (WNs) is proposed to linearize wideband RF power amplifiers. A complex wavelet network with tapped delay lines is applied to construct the predistorter and then a complex backpropagation algorithm is developed to train the predistorter parameters. The simulation results show that compared with the previously published feed-forward neural network predistortion method, the proposed method provides faster convergence rate and better performance in reducing out-of-band spectral regrowth.展开更多
A prototype of hybrid neural recording interface has been developed for extracellular neural recording. It consists of a silicon-based plane microelectrode array and a CMOS low noise neural amplifier chip. The neural ...A prototype of hybrid neural recording interface has been developed for extracellular neural recording. It consists of a silicon-based plane microelectrode array and a CMOS low noise neural amplifier chip. The neural amplifier chip is designed and implemented in 0.18 μm N-well CMOS 1P6M technology. The area of the neural preamplifier is only 0.042 mm2 with a gain of 48.3 dB. The input equivalent noise is 4.73 btVrms within pass bands of 4 kHz. To avoid cable tethering for high dense mul- tichannel neural recording interface and make it compact, flip-chip bonding is used to integrate the preamplifier chip and the microelectrode together. The hybrid device measures 3 mm×5.5 mm×330μm, which is convenient for implant or in-vivo neu- ral recording. The hybrid device was testified in in-vivo experiment. Neural signals were recorded from hippocampus region of anesthetized Sprague Dawley rats successfully.展开更多
In this paper, a low-noise preamplifier for MRI is designed and studied. A noise matching network consisting of three elements is presented. To the single-stage AsGa-FET preamplifier working at 128 MHz, the measured g...In this paper, a low-noise preamplifier for MRI is designed and studied. A noise matching network consisting of three elements is presented. To the single-stage AsGa-FET preamplifier working at 128 MHz, the measured gain through network analyzer (HP8712C) and noise figure through noise figure analyzer (8970B) are 25 and 0.43 dB, respectively.展开更多
文摘A monolithic integrated CMOS preamplifier is presented for neural recording applications. Two AC-coupied capacitors are used to eliminate the large and random DC offsets existing in the electrode-electrolyte interface. Diode-connected nMOS transistors with a negative voltage between the gate and source are candidates for the large resistors necessary for the preamplifier. A novel analysis is given to determine the noise power spectral density. Simulation results show that the two-stage CMOS preamplifier in a closed-loop capacitive feedback configuration provides an AC in-band gain of 38.8dB,a DC gain of 0,and an input-referred noise of 277nVmax, integrated from 0. 1Hz to 1kHz. The preamplifier can eliminate the DC offset voltage and has low input-referred noise by novel circuit configuration and theoretical analysis.
文摘A high gain cascade connected preamplifier for optical receivers is developed with 0.5μm GaAs PHEMT technology from the Nanjing Electronic Devices Institute. To begin with, the transimpedance amplifier has a -3dB bandwidth of 10GHz, with a small signal gain of around 9dB. The post-stage distributed amplifier （DA） has a -3dB bandwidth of close to 20GHz,with a small signal gain of around 12dB. As a whole,the cascade preamplifier has a measured small signal gain of 21.3dB and a transimpedance of 55.3dBΩ in a 50Ω system. With a higher signal-to-noise ratio than that of the TIA and a markedly improved waveform distortion compared with that of the DA, the measured output eye diagram for 10Gb/s NRZ pseudorandom binary sequence is clear and symmetric.
文摘A single power supply common-gate （CG） current mode transimpedance preamplifier （TIA） is developed with a 0.5μm GaAs PHEMT process. The amplifier has a measured - 3dB bandwidth of 7. 5GHz and a transimpedance gain of 45dBΩ. Both the input and output voltage standing wave ratios （VSWR） are less than 2 within the bandwidth. The equivalent input noise current spectral density varies from 14.3 to 22pA/√Hz, with an average value of 17. 2pA/√Hz. Having a timing jitter of 14ps and eye amplitude of about 138mV,the measured output eye diagram for 10Gb/s NRZ pseudorandom binary sequence （PRBS） is clear and satisfactory.
基金The Key Technology Research and Development Program of Jiangsu Province ( No. BE2008128)
文摘A 10 Gbit/s burst-mode preamplifier is designed for passive optical networks （PONs）. To achieve a high dynamic range and fast response, the circuit is DC coupled, and a feed-back type peak detector is designed to perform auto-gaincontrol and threshold extraction. Regulated cascade （RGC） architecture is exploited as the input stage to reduce the input impedance of the circuit and isolate the large parasitic capacitance including the photodiode capacitance from the determination pole, thus increasing the bandwidth. This preamplifier is implemented using the low-cost 0. 13 ixm CMOS technology. The die area is 425 μm × 475 μm and the total power dissipation is 23.4 mW. The test results indicate that the preamplifier can work at a speed from 1.25 to 10.312 5 Gbit/s, providing a high transimpedance gain of 64.0 dBΩ and a low gain of 54. 6 dBl2 with a dynamic input range of over 22.9 dB. The equivalent input noise current is 23. 4 pA/ Hz1/2. The proposed burst amplifier satisfies related specifications defined in 10G-EPON and XG-PON standards.
文摘A new probe for atmospheric electric field mill is introduced.It consists of three parts：signal acquisition circuit for atmospheric electric field,preamplifier circuit and phase sensitive detection circuit.The signal acquisition circuit adopts the double-stator structure to form differential input circuit,thus double-precision is obtained.Preamplifier circuit is made of current-to-voltage （I-V） conversion circuit,differential amplifier circtuit and secondary amplifying circuit.The polarity of electric field is obtained via phase sensitive detection circuit.Simulation results are obtained using Multisim,and the feasibility of the designed probe is verified.
基金Project (No. 60372026) supported by the National Natural ScienceFoundation of China
文摘RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques. Nevertheless, in wideband communication systems, PA memory effects can no longer be ignored and memoryless predistortion cannot linearize PAs effectively. After analyzing PA memory effects, a novel predistortion method based on wavelet networks (WNs) is proposed to linearize wideband RF power amplifiers. A complex wavelet network with tapped delay lines is applied to construct the predistorter and then a complex backpropagation algorithm is developed to train the predistorter parameters. The simulation results show that compared with the previously published feed-forward neural network predistortion method, the proposed method provides faster convergence rate and better performance in reducing out-of-band spectral regrowth.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.61076023,61275200,31070965)the National Basic Research Program of China("973" project)(Grant No.2011CB933203)the National High-Tech Research and Development Program of China("863" Project)(Grant No.2012AA030308)
文摘A prototype of hybrid neural recording interface has been developed for extracellular neural recording. It consists of a silicon-based plane microelectrode array and a CMOS low noise neural amplifier chip. The neural amplifier chip is designed and implemented in 0.18 μm N-well CMOS 1P6M technology. The area of the neural preamplifier is only 0.042 mm2 with a gain of 48.3 dB. The input equivalent noise is 4.73 btVrms within pass bands of 4 kHz. To avoid cable tethering for high dense mul- tichannel neural recording interface and make it compact, flip-chip bonding is used to integrate the preamplifier chip and the microelectrode together. The hybrid device measures 3 mm×5.5 mm×330μm, which is convenient for implant or in-vivo neu- ral recording. The hybrid device was testified in in-vivo experiment. Neural signals were recorded from hippocampus region of anesthetized Sprague Dawley rats successfully.
基金supported by the National Natural Science Foundation of China (Grant No. 60871001)
文摘In this paper, a low-noise preamplifier for MRI is designed and studied. A noise matching network consisting of three elements is presented. To the single-stage AsGa-FET preamplifier working at 128 MHz, the measured gain through network analyzer (HP8712C) and noise figure through noise figure analyzer (8970B) are 25 and 0.43 dB, respectively.
