Research interests have recently been directed towards electrical discharges in multi-phase environments.Natural electrical discharges,such as lightning and coronas,occur in the Earth's atmosphere,which is actually a...Research interests have recently been directed towards electrical discharges in multi-phase environments.Natural electrical discharges,such as lightning and coronas,occur in the Earth's atmosphere,which is actually a mixture of gaseous phase(air) and suspended solid and liquid particulate matters(PMs).An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators(ESPs),which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it.Electrical discharges in multi-phase environments,the knowledge of which is scarce,are becoming an attractive research subject,offering a wide variety of possible discharges and multi-phase environments to be studied.This paper is an introduction to electrical discharges in multi-phase environments.It is focused on DC negative coronas and accompanying electrohydrodynamic(EHD) flows in a gaseous two-phase fluid formed by air(a gaseous phase) and solid PM(a solid phase),run under laboratory conditions.The introduction is based on a review of the relevant literature.Two cases will be considered:the first case is of a gaseous two-phase fluid,initially motionless in a closed chamber before being subjected to a negative corona(with the needle-toplate electrode arrangement),which afterwards induces an EHD flow in the chamber,and the second,of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes.This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single-or two-phase fluids,and for engineers who work on designing EHD devices(such as ESPs,EHD pumps,and smoke detectors).展开更多
This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibrat...This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibration circuit is used in the analog baseband chain,and the programmable bandwidth is 1.8/2.5/3/3.5/4 MHz with an attenuation of 26/62 dB at offsets of 1.25/4 MHz.The baseband programmable gain amplifier can achieve a linear 40-dB gain range with 0.5-dB steps.Design trade-offs are carefully considered in designing the baseband circuit,and an automatic calibration circuit is used to achieve the bandwidth accuracy of 2%.A DC offset cancellation loop is also introduced to remove the offset from the layout and self-mixing,and the remaining offset voltage is only 1.87 mV.Implemented in a 0.13-μm SiGe technology with a 0.6-mm2 die size,this baseband achieves IIP3 of 23.16 dBm and dissipates 22.4 mA under a 2.5-V supply.展开更多
基金supported by the National Science Centre(Grant No.UMO-2013/09/B/ST8/02054)
文摘Research interests have recently been directed towards electrical discharges in multi-phase environments.Natural electrical discharges,such as lightning and coronas,occur in the Earth's atmosphere,which is actually a mixture of gaseous phase(air) and suspended solid and liquid particulate matters(PMs).An example of an anthropogenic gaseous multi-phase environment is the flow of flue gas through electrostatic precipitators(ESPs),which are generally regarded as a mixture of a post-combustion gas with solid PM and microdroplets suspended in it.Electrical discharges in multi-phase environments,the knowledge of which is scarce,are becoming an attractive research subject,offering a wide variety of possible discharges and multi-phase environments to be studied.This paper is an introduction to electrical discharges in multi-phase environments.It is focused on DC negative coronas and accompanying electrohydrodynamic(EHD) flows in a gaseous two-phase fluid formed by air(a gaseous phase) and solid PM(a solid phase),run under laboratory conditions.The introduction is based on a review of the relevant literature.Two cases will be considered:the first case is of a gaseous two-phase fluid,initially motionless in a closed chamber before being subjected to a negative corona(with the needle-toplate electrode arrangement),which afterwards induces an EHD flow in the chamber,and the second,of a gaseous two-phase fluid flowing transversely with respect to the needle-to-plate electrode axis along a chamber with a corona discharge running between the electrodes.This review-based introductory paper should be of interest to theoretical researchers and modellers in the field of negative corona discharges in single-or two-phase fluids,and for engineers who work on designing EHD devices(such as ESPs,EHD pumps,and smoke detectors).
基金Project supported by the Provincial and Ministerial Industry-Academia Cooperation Project of China(No.2009A090100019)
文摘This paper presents post-layout simulated results of an analog baseband chain for mobile and multimedia applications in a 0.13-μm SiGe BiCMOS process.A programmable 7th-order Chebyshev low pass filter with a calibration circuit is used in the analog baseband chain,and the programmable bandwidth is 1.8/2.5/3/3.5/4 MHz with an attenuation of 26/62 dB at offsets of 1.25/4 MHz.The baseband programmable gain amplifier can achieve a linear 40-dB gain range with 0.5-dB steps.Design trade-offs are carefully considered in designing the baseband circuit,and an automatic calibration circuit is used to achieve the bandwidth accuracy of 2%.A DC offset cancellation loop is also introduced to remove the offset from the layout and self-mixing,and the remaining offset voltage is only 1.87 mV.Implemented in a 0.13-μm SiGe technology with a 0.6-mm2 die size,this baseband achieves IIP3 of 23.16 dBm and dissipates 22.4 mA under a 2.5-V supply.