A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The ...A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The LNA, fabricated in the 0.18μm 1P6M CMOS technology, adopts a gain-switched technique to increase the linearity and enlarge the dynamic range. The mixer is an IQ-based passive topology. Measurements of the CMOS chip are performed on the FR-4 PCB and the input is matched to 50Ω. Combining LNA and mixer, the front-end measured performances in high gain state are： -15dB of Sll, 18.5dB of voltage gain, 4.6dB of noise figure, 15dBm of IIP3, 85dBm to -10dBm dynamic range. The full circuit drains 6mA from a 1.8V supply.展开更多
The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an an...The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an antenna system with minimal irradiation on user＇s body is analyzed. In this case, the zone itself, where the area of a weak field （a dark spot） is created, is generally not approachable for sensors installation. In order to counteract the disturbance of the system operation due to presence of different metallic objects in close proximity to the radiators, two methods based on two information sources are studied. These information sources are antennas driving currents and fields at a predetermined point outside the given area. As an example, the antenna system used in the compensation method for reducing human＇s body irradiation, to which a metal object approaches, is analyzed. The conditions of severe external actions are considered： a great metal body and a small distance from this body to the dark spot. It is shown that under these conditions of severe external actions the second method based on the field values measuring demonstrates a higher efficiency. A block scheme for structure of an automatic adjustment is suggested. The considered problem is a common one, and developers of radio circuits are faced with them constantly.展开更多
The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,t...The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,the robot moves to three different positions to capture the images of three targets.Then the transformation matrix X between camera and tool center point(TCP) coordinate systems can be calculated by using the known parameters of robot and the extrinsic parameters,and finally the multi-view coordinate system can be transformed into robot coordinate system by the transformation matrix X.With the help of robot,the multi-view point cloud can be easily transformed into a unified coordinate system.By using robot,the measurement doesn't need any mark.Experimental results show that the method is effective.展开更多
The authors investigate the global existence and semiclassical limit of weak solutions to a sixth-order parabolic system,which is a quantum-corrected macroscopic model derived recently to simulate the quantum effects ...The authors investigate the global existence and semiclassical limit of weak solutions to a sixth-order parabolic system,which is a quantum-corrected macroscopic model derived recently to simulate the quantum effects in miniaturized semiconductor devices.展开更多
Despite fluctuations in embryo size within a species,the spatial gene expression pattern and hence the embryonic structure can nonetheless maintain the correct proportion to the embryo size.This is known as the scalin...Despite fluctuations in embryo size within a species,the spatial gene expression pattern and hence the embryonic structure can nonetheless maintain the correct proportion to the embryo size.This is known as the scaling phenomenon.For morphogen-induced patterning of gene expression,the positional information encoded in the local morphogen concentrations is decoded by the downstream genetic network(the decoder).In this paper,we show that the requirement of scaling sets severe constraints on the geometric structure of such a local decoder,which in turn enables deduction of mutants’behavior and extraction of regulation information without going into any molecular details.We demonstrate that the Drosophila gap gene system achieves scaling in the way consistent with our theory—the decoder geometry required by scaling correctly accounts for the observed gap gene expression pattern in nearly all maternal morphogen mutants.Furthermore,the regulation logic and the coding/decoding strategy of the gap gene system can also be revealed from the decoder geometry.Our work provides a general theoretical framework for a large class of problems where scaling output is achieved by non-scaling inputs and a local decoder,as well as a unified understanding of scaling,mutants’behavior,and gene regulation for the Drosophila gap gene system.展开更多
文摘A 2.4GHz 0.18μm CMOS gain-switched single-end Low Noise Amplifier （LNA） and a passive mixer with no external balun for near-zero-IF （Intermediate Frequency）/RF （Radio Frequency） applications are described. The LNA, fabricated in the 0.18μm 1P6M CMOS technology, adopts a gain-switched technique to increase the linearity and enlarge the dynamic range. The mixer is an IQ-based passive topology. Measurements of the CMOS chip are performed on the FR-4 PCB and the input is matched to 50Ω. Combining LNA and mixer, the front-end measured performances in high gain state are： -15dB of Sll, 18.5dB of voltage gain, 4.6dB of noise figure, 15dBm of IIP3, 85dBm to -10dBm dynamic range. The full circuit drains 6mA from a 1.8V supply.
文摘The operation of a complicated radiators structure creating a required field in a given area is disturbed often due to different external actions. As an example, the impact of metallic objects approaching off to an antenna system with minimal irradiation on user＇s body is analyzed. In this case, the zone itself, where the area of a weak field （a dark spot） is created, is generally not approachable for sensors installation. In order to counteract the disturbance of the system operation due to presence of different metallic objects in close proximity to the radiators, two methods based on two information sources are studied. These information sources are antennas driving currents and fields at a predetermined point outside the given area. As an example, the antenna system used in the compensation method for reducing human＇s body irradiation, to which a metal object approaches, is analyzed. The conditions of severe external actions are considered： a great metal body and a small distance from this body to the dark spot. It is shown that under these conditions of severe external actions the second method based on the field values measuring demonstrates a higher efficiency. A block scheme for structure of an automatic adjustment is suggested. The considered problem is a common one, and developers of radio circuits are faced with them constantly.
基金supported by the National Natural Science Foundation of China(Nos.60808020 and 61078041)the National Science and Technology Support Program(No.2014BAH03F01)+2 种基金the Tianjin Research Program of Application Foundation and Advanced Technology(No.10JCYBJC07200)the Tianjin Small and Medium Enterprise Innovation Fund(No.12ZXCXGX11800)the Technology Program of Tianjin Municipal Education Commission(No.20130324)
文摘The registration of point cloud is important for large object measurement.A measurement method for coordinate system transformation based on robot is proposed in this paper.Firstly,for obtaining extrinsic parameters,the robot moves to three different positions to capture the images of three targets.Then the transformation matrix X between camera and tool center point(TCP) coordinate systems can be calculated by using the known parameters of robot and the extrinsic parameters,and finally the multi-view coordinate system can be transformed into robot coordinate system by the transformation matrix X.With the help of robot,the multi-view point cloud can be easily transformed into a unified coordinate system.By using robot,the measurement doesn't need any mark.Experimental results show that the method is effective.
基金Project supported by the National Natural Science Foundation of China (Nos. 10871112, 10771008)the Research Fund for the Doctoral Program of Higher Education of China (No. 20090005120009)+1 种基金 the Fundamental Research Funds for the Central Universities (No. BUPT2009RC0702)the Talents Scheme Funds of BUPT
文摘The authors investigate the global existence and semiclassical limit of weak solutions to a sixth-order parabolic system,which is a quantum-corrected macroscopic model derived recently to simulate the quantum effects in miniaturized semiconductor devices.
基金supported by the National Natural Science Foundation of China(12090053 and 32088101)。
文摘Despite fluctuations in embryo size within a species,the spatial gene expression pattern and hence the embryonic structure can nonetheless maintain the correct proportion to the embryo size.This is known as the scaling phenomenon.For morphogen-induced patterning of gene expression,the positional information encoded in the local morphogen concentrations is decoded by the downstream genetic network(the decoder).In this paper,we show that the requirement of scaling sets severe constraints on the geometric structure of such a local decoder,which in turn enables deduction of mutants’behavior and extraction of regulation information without going into any molecular details.We demonstrate that the Drosophila gap gene system achieves scaling in the way consistent with our theory—the decoder geometry required by scaling correctly accounts for the observed gap gene expression pattern in nearly all maternal morphogen mutants.Furthermore,the regulation logic and the coding/decoding strategy of the gap gene system can also be revealed from the decoder geometry.Our work provides a general theoretical framework for a large class of problems where scaling output is achieved by non-scaling inputs and a local decoder,as well as a unified understanding of scaling,mutants’behavior,and gene regulation for the Drosophila gap gene system.
