A compacted and low-offset low-power CMOS am- plifier for biosensor application is presented in this paper. It includes a low offset Op-Amp and a high precision current reference. With a novel continuous-time DC offse...A compacted and low-offset low-power CMOS am- plifier for biosensor application is presented in this paper. It includes a low offset Op-Amp and a high precision current reference. With a novel continuous-time DC offset rejection scheme, the IC achieves lower offset voltage and lower power consumption compared to previous designs. This configuration rejects large DC offset and drift that exist at the skin-electrode interface without the need of external components. The proposed amplifier has been implemented in SMIC 0.18-μm 1P6M CMOS technol-ogy, with an active silicon area of 100 μm by 120 μm. The back-annotated simulation results demonstrated the circuit features the systematic offset voltage less than 80 μV, the offset drift about 0.27 μV/℃ for temperature ranging from –30℃ to 100℃ and the total power dissipation consumed as low as 37.8 μW from a 1.8 V single supply. It dedicated to monitor low amplitude biomedical signals recording.展开更多
The effect of courtyards as microclimate modifiers on the sustainability of traditional houses in a region with 13Wks mesoclimate in Iran was explored. The principle behind traditional Iranian courtyards was investiga...The effect of courtyards as microclimate modifiers on the sustainability of traditional houses in a region with 13Wks mesoclimate in Iran was explored. The principle behind traditional Iranian courtyards was investigated to identify the most intluential physical-environmental character- istics that can effectively improve energy efficiency in contemporary residential buildings. A field study was performed to analyze various physical elements of six valuable traditional courtyard houses located in a region with BWks mesodimate in Iran. These elements included the orientation, extension, rotation angle, dimensions, and proportions of enclosed and open spaces, as well as physical bodies （opaque waUs）, transparent surfaces （openings）, and natural elements （water and soil）. Results showed that most of the studied Iranian courtyards were particularly designed to enable orientation, dimension, and proportion to act as microdimate modifiers. All survey-based data were sumrnarized and integrated to propose a physical- environmental design model for courtyards as a useful energy-efficient strategy for contem- porary sustainable housing in a region with BWks mesoctimate. The proposed model can be generalized to all design cases located in areas with similar climatic conditions.展开更多
To compensate for the loss of cartier density along the active region of quantum-dot semiconductor optical amplifiers （QD-SOAs）, tapered structure of the waveguide is introduced. In this paper, a method for theoreti...To compensate for the loss of cartier density along the active region of quantum-dot semiconductor optical amplifiers （QD-SOAs）, tapered structure of the waveguide is introduced. In this paper, a method for theoretically modeling of such devices is proposed, and according to that model different shapes of tapered waveguides are studied. This study is pivoted around the optical gain and cross-gain modulation （XGM） of the QD- SOA under investigation to show how altering the shape of the waveguide affects the main characteristics of the device. For doing so, the rate equation model has been employed and solved through finite difference method and MATLAB ODE. Through this, as long as monotonically increasing profiles for the width of the waveguide are used, the shape of the waveguide has a negligible effect on the gain which mainly depends on the width ratio of the waveguide output to its input. However, this carrier compensation has adverse effect on the XGM, where its efficiency rely on how the pump signal can effectively reduce carder density and upset the gain.展开更多
We present results from theoretical analysis of the phase dynamics in semiconductor optical amplifiers(SOAs).In particular,we focus on an aspect of the ultra-fast phase recovery that currently does not have adequate i...We present results from theoretical analysis of the phase dynamics in semiconductor optical amplifiers(SOAs).In particular,we focus on an aspect of the ultra-fast phase recovery that currently does not have adequate in-depth theoretical analysis and clear explanation of the physical mechanism.We build up a numerical model to analyze the ultra-fast phase recovery of semiconductor optical amplifiers in details.To investigate the phase response characteristics,we analyze the different contributions to the phase shift,including intra-band effects such as carrier heating,spectral hole burning,and inter-band effects such as carrier depletion.In addition,the impact of the pulses energy on phase shift is also investigated.Based on the analysis of phase response characteristics,we further explain the reason why a delay occurs between gain response and phase response.The analysis results are in good agreement with the reported experimental results.The results presented in this paper are useful for the SOA-based ultra-fast optical signal processing,such as optical switches,optical logic gates,and optical Add/Drop multiplexer.展开更多
文摘A compacted and low-offset low-power CMOS am- plifier for biosensor application is presented in this paper. It includes a low offset Op-Amp and a high precision current reference. With a novel continuous-time DC offset rejection scheme, the IC achieves lower offset voltage and lower power consumption compared to previous designs. This configuration rejects large DC offset and drift that exist at the skin-electrode interface without the need of external components. The proposed amplifier has been implemented in SMIC 0.18-μm 1P6M CMOS technol-ogy, with an active silicon area of 100 μm by 120 μm. The back-annotated simulation results demonstrated the circuit features the systematic offset voltage less than 80 μV, the offset drift about 0.27 μV/℃ for temperature ranging from –30℃ to 100℃ and the total power dissipation consumed as low as 37.8 μW from a 1.8 V single supply. It dedicated to monitor low amplitude biomedical signals recording.
文摘The effect of courtyards as microclimate modifiers on the sustainability of traditional houses in a region with 13Wks mesoclimate in Iran was explored. The principle behind traditional Iranian courtyards was investigated to identify the most intluential physical-environmental character- istics that can effectively improve energy efficiency in contemporary residential buildings. A field study was performed to analyze various physical elements of six valuable traditional courtyard houses located in a region with BWks mesodimate in Iran. These elements included the orientation, extension, rotation angle, dimensions, and proportions of enclosed and open spaces, as well as physical bodies （opaque waUs）, transparent surfaces （openings）, and natural elements （water and soil）. Results showed that most of the studied Iranian courtyards were particularly designed to enable orientation, dimension, and proportion to act as microdimate modifiers. All survey-based data were sumrnarized and integrated to propose a physical- environmental design model for courtyards as a useful energy-efficient strategy for contem- porary sustainable housing in a region with BWks mesoctimate. The proposed model can be generalized to all design cases located in areas with similar climatic conditions.
文摘To compensate for the loss of cartier density along the active region of quantum-dot semiconductor optical amplifiers （QD-SOAs）, tapered structure of the waveguide is introduced. In this paper, a method for theoretically modeling of such devices is proposed, and according to that model different shapes of tapered waveguides are studied. This study is pivoted around the optical gain and cross-gain modulation （XGM） of the QD- SOA under investigation to show how altering the shape of the waveguide affects the main characteristics of the device. For doing so, the rate equation model has been employed and solved through finite difference method and MATLAB ODE. Through this, as long as monotonically increasing profiles for the width of the waveguide are used, the shape of the waveguide has a negligible effect on the gain which mainly depends on the width ratio of the waveguide output to its input. However, this carrier compensation has adverse effect on the XGM, where its efficiency rely on how the pump signal can effectively reduce carder density and upset the gain.
基金supported by the National Basic Research Program of China (2011CB301705)National Natural Science Foundation of China(60925019,61090393 and 60907008)
文摘We present results from theoretical analysis of the phase dynamics in semiconductor optical amplifiers(SOAs).In particular,we focus on an aspect of the ultra-fast phase recovery that currently does not have adequate in-depth theoretical analysis and clear explanation of the physical mechanism.We build up a numerical model to analyze the ultra-fast phase recovery of semiconductor optical amplifiers in details.To investigate the phase response characteristics,we analyze the different contributions to the phase shift,including intra-band effects such as carrier heating,spectral hole burning,and inter-band effects such as carrier depletion.In addition,the impact of the pulses energy on phase shift is also investigated.Based on the analysis of phase response characteristics,we further explain the reason why a delay occurs between gain response and phase response.The analysis results are in good agreement with the reported experimental results.The results presented in this paper are useful for the SOA-based ultra-fast optical signal processing,such as optical switches,optical logic gates,and optical Add/Drop multiplexer.
