该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μ...该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μm CMOS工艺研制了5G毫米波反向阵芯片,包括发射前端、接收前端及跟踪锁相环等核心模块,其中发射及接收前端芯片采用次谐波混频及跨导增强等技术,分别实现了19.5 d B和18.7 d B的实测转换增益。所实现的跟踪锁相环芯片具备双模工作优势,可根据不同参考信号支持幅度调制及相位调制,实测输出信号相噪优于–125 dBc/Hz@100 kHz。该文给出的测试结果验证了所提5G毫米波反向阵通信架构及其CMOS芯片实现的可行性,从而为5G/6G毫米波通信探索了一种架构极简、成本极低、拓展性强的新方案。展开更多
The array laterolog is an important tool for complex formation logging evaluation due to its high resolution and large detection depth.However,its logging responses are seriously affected by leakage events due to the ...The array laterolog is an important tool for complex formation logging evaluation due to its high resolution and large detection depth.However,its logging responses are seriously affected by leakage events due to the surrounding rock and by mud invasion.These factors must be considered when inverting array lateral logging data,so that the inversion results reflect the true formation conditions as much as possible.The difficulties encountered in the inversion of array lateral logging data are:too many inversion parameters cause the calculation of the Jacobian matrix to be difficult and the time required to select the initial inversion values due to the slow forward-modeling speed.In this paper,we develop a fast processing method for array laterolog data.First,it is important to clearly define the main controlling factors for the array laterolog response,such as thickness,the surrounding rock,and invasion.Second,based on a depth-window technique,processing the array laterolog data for the entire well is transformed into multiple 2 D inversions of the layers using a series of continuous depth windows.For each formation in a depth window,combined with the1 D equivalent fast-forward algorithm,rapid extraction of the radial resistivity profile of the formation is achieved.Finally,the 1 D inversion result is used as the initial state to further eliminate the influence of surrounding rocks and layer thicknesses on the apparent resistivity response.Numerical simulation results show that the factors affecting the response of the array laterolog are the invasion properties,the layer thicknesses,and the surrounding rocks;the windowing technique greatly reduces the number of inversion parameters needed and improves the inversion speed.A real application of the method shows that 2 D inversion can rapidly reconstruct the actual resistivity distribution and improve the accuracy of reservoir saturation calculations.展开更多
Let F be a field and let resA = rank(A - I) for any A in GLnF. We prove that every matrix in SLnF is a product of at most [resA/2] + 2 commutators of reflections for n 】 2 except for n - 2 and F = F2.
Wu, Chen, and Cai （2007） investigated chaos synchronization of two identical generalized Lorenz systems unidirectionally coupled by a linear state error feedback controller. However, bidirec- tional coupling in real...Wu, Chen, and Cai （2007） investigated chaos synchronization of two identical generalized Lorenz systems unidirectionally coupled by a linear state error feedback controller. However, bidirec- tional coupling in real life such as complex dynamical networks is more universal. This paper provides a unified method for analyzing chaos synchronization of two bidirectionally coupled generalized Lorenz systems. Some sufficient synchronization conditions for some special coupling matrices （diagonal ma- trices, so-called dislocated coupling matrices, and so on） are derived through rigorously mathematical theory. In particular, for the classical Lorenz system, the authors obtain synchronization criteria which only depend upon its parameters using new estimation of the ultimate bounds of Lorenz system （Chaos, Solitons, and Fractals, 2005）. The criteria are then applied to four typical generalized Lorenz systems in the numerical simulations for verification.展开更多
In this letter a Monte Carlo(MC) algorithm is used to simulate the propagation of polarized light in double-layer turbid media and the 2-dimentional backscattered Stokes vectors and Mueller matrices are obtained.Relat...In this letter a Monte Carlo(MC) algorithm is used to simulate the propagation of polarized light in double-layer turbid media and the 2-dimentional backscattered Stokes vectors and Mueller matrices are obtained.Relationships between backscattered Mueller matrix and optical properties,such as scattering,absorption and layered structure,are discussed in detail.Integrating the 2-dimentional Mueller matrix elements along radial and azimuthal directions,we obtain a reverse trend with respect to the optical parameters for upper and lower layers,which suggests possibilities for discriminating subtle optical properties in a double-layer structure using backscattered polarization patterns such as Mueller matrix.展开更多
文摘该文首次报道了一种极简构架的5G毫米波反向阵设计原理及其CMOS芯片实现技术。该毫米波反向阵极简构架,利用次谐波混频器提供相位共轭和阵列反向功能,无需移相电路及波束控制系统,便可实现波束自动回溯移动通信功能。该文采用国产0.18μm CMOS工艺研制了5G毫米波反向阵芯片,包括发射前端、接收前端及跟踪锁相环等核心模块,其中发射及接收前端芯片采用次谐波混频及跨导增强等技术,分别实现了19.5 d B和18.7 d B的实测转换增益。所实现的跟踪锁相环芯片具备双模工作优势,可根据不同参考信号支持幅度调制及相位调制,实测输出信号相噪优于–125 dBc/Hz@100 kHz。该文给出的测试结果验证了所提5G毫米波反向阵通信架构及其CMOS芯片实现的可行性,从而为5G/6G毫米波通信探索了一种架构极简、成本极低、拓展性强的新方案。
基金supported by the National Science and Technology Major Project of China(NO.2017ZX05005-005-005,NO.2016ZX05014-002-001 and No.2016ZX05002-005-001)the Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA14010204
文摘The array laterolog is an important tool for complex formation logging evaluation due to its high resolution and large detection depth.However,its logging responses are seriously affected by leakage events due to the surrounding rock and by mud invasion.These factors must be considered when inverting array lateral logging data,so that the inversion results reflect the true formation conditions as much as possible.The difficulties encountered in the inversion of array lateral logging data are:too many inversion parameters cause the calculation of the Jacobian matrix to be difficult and the time required to select the initial inversion values due to the slow forward-modeling speed.In this paper,we develop a fast processing method for array laterolog data.First,it is important to clearly define the main controlling factors for the array laterolog response,such as thickness,the surrounding rock,and invasion.Second,based on a depth-window technique,processing the array laterolog data for the entire well is transformed into multiple 2 D inversions of the layers using a series of continuous depth windows.For each formation in a depth window,combined with the1 D equivalent fast-forward algorithm,rapid extraction of the radial resistivity profile of the formation is achieved.Finally,the 1 D inversion result is used as the initial state to further eliminate the influence of surrounding rocks and layer thicknesses on the apparent resistivity response.Numerical simulation results show that the factors affecting the response of the array laterolog are the invasion properties,the layer thicknesses,and the surrounding rocks;the windowing technique greatly reduces the number of inversion parameters needed and improves the inversion speed.A real application of the method shows that 2 D inversion can rapidly reconstruct the actual resistivity distribution and improve the accuracy of reservoir saturation calculations.
基金This research is supported by the National Natural Science Foundation of China.
文摘Let F be a field and let resA = rank(A - I) for any A in GLnF. We prove that every matrix in SLnF is a product of at most [resA/2] + 2 commutators of reflections for n 】 2 except for n - 2 and F = F2.
基金supported by the National Natural Science Foundation of China under Grant Nos.60804039 and 60974081the National Basic Research Program of China under Grant No.2007CB310805
文摘Wu, Chen, and Cai （2007） investigated chaos synchronization of two identical generalized Lorenz systems unidirectionally coupled by a linear state error feedback controller. However, bidirec- tional coupling in real life such as complex dynamical networks is more universal. This paper provides a unified method for analyzing chaos synchronization of two bidirectionally coupled generalized Lorenz systems. Some sufficient synchronization conditions for some special coupling matrices （diagonal ma- trices, so-called dislocated coupling matrices, and so on） are derived through rigorously mathematical theory. In particular, for the classical Lorenz system, the authors obtain synchronization criteria which only depend upon its parameters using new estimation of the ultimate bounds of Lorenz system （Chaos, Solitons, and Fractals, 2005）. The criteria are then applied to four typical generalized Lorenz systems in the numerical simulations for verification.
基金supported by the Governmental Education Bureau of Fujian Province(No.JA10068)the 2009 Project for Scientific and Technical Development of Xiamen (No.3502Z20099007)
文摘In this letter a Monte Carlo(MC) algorithm is used to simulate the propagation of polarized light in double-layer turbid media and the 2-dimentional backscattered Stokes vectors and Mueller matrices are obtained.Relationships between backscattered Mueller matrix and optical properties,such as scattering,absorption and layered structure,are discussed in detail.Integrating the 2-dimentional Mueller matrix elements along radial and azimuthal directions,we obtain a reverse trend with respect to the optical parameters for upper and lower layers,which suggests possibilities for discriminating subtle optical properties in a double-layer structure using backscattered polarization patterns such as Mueller matrix.
