提出并设计了一种低成本宽带90°巴伦电路结构,电路由宽带耦合威尔金森功分器、弱耦合线和扇形阶跃阻抗谐振器级联的宽带90°移相器组成。利用电磁仿真软件HFSS对工作在中心频率为1.65 GHz的微带电路进行建模和仿真。采用PCB工...提出并设计了一种低成本宽带90°巴伦电路结构,电路由宽带耦合威尔金森功分器、弱耦合线和扇形阶跃阻抗谐振器级联的宽带90°移相器组成。利用电磁仿真软件HFSS对工作在中心频率为1.65 GHz的微带电路进行建模和仿真。采用PCB工艺制作了电路实物并利用矢量网络分析仪进行测试;对比得出仿真与测试结果十分吻合,该巴伦实测相对带宽大于117.0%(0.65~2.58 GHz),带内各端口回波损耗好于12.6 d B,输出端口隔离度大于13.1 d B,带内插入损耗小于0.5 d B,相位误差小于90°±7.6°。与现有的结构和设计相比,该巴伦不仅具有更大的工作频带和单层电路布局,而且具有容易加工、成本低的优点。展开更多
Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variationa...Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variational method and quantum statistical theory.The results show that the absolute value of the induced potential of the bipolaron increases with increasing the electron-phonon coupling strength,but decreases with increasing the temperature and the distance of electrons,respectively;the absolute value of the effective potential increases with increasing the radius of the quantum dot,electron-phonon coupling strength and the distance of electrons,respectively,but decreases with increasing the temperature;the temperature and electron-phonon interaction have the important influence on the formation and state properties of the bipolaron:the bipolarons in the bound state are closer and more stable when the electron-phonon coupling strength is larger or the temperature is lower;the confinement potential and coulomb repulsive potential between electrons are unfavorable to the formation of bipolarons in the bound state.展开更多
Recently, cavity optomechanics has become a rapidly developing research field exploring the coupling between the optical field and mechanical oscillation. Cavity optomechanical systems were predicted to exhibit rich a...Recently, cavity optomechanics has become a rapidly developing research field exploring the coupling between the optical field and mechanical oscillation. Cavity optomechanical systems were predicted to exhibit rich and nontrivial effects due to the nonlinear optomechanical interaction. However, most progress during the past years have focused on the linearization of the optomechanical interaction, which ignored the intrinsic nonlinear nature of the optomechanical coupling. Exploring nonlinear optomechanical interaction is of growing interest in both classical and quantum mechanisms, and nonlinear optomechanical interaction has emerged as an important new frontier in cavity optomechanics. It enables many applications ranging from single-photon sources to generation of nonclassical states. Here, we give a brief review of these developments and discuss some of the current challenges in this field.展开更多
文摘提出并设计了一种低成本宽带90°巴伦电路结构,电路由宽带耦合威尔金森功分器、弱耦合线和扇形阶跃阻抗谐振器级联的宽带90°移相器组成。利用电磁仿真软件HFSS对工作在中心频率为1.65 GHz的微带电路进行建模和仿真。采用PCB工艺制作了电路实物并利用矢量网络分析仪进行测试;对比得出仿真与测试结果十分吻合,该巴伦实测相对带宽大于117.0%(0.65~2.58 GHz),带内各端口回波损耗好于12.6 d B,输出端口隔离度大于13.1 d B,带内插入损耗小于0.5 d B,相位误差小于90°±7.6°。与现有的结构和设计相比,该巴伦不仅具有更大的工作频带和单层电路布局,而且具有容易加工、成本低的优点。
基金Supported by the Items of Institution of Higher Education Scientific Research of Inner Mongolia under Grant No. NJ101116
文摘Based on the Huybrechts' linear-combination operator,effects of thermal lattice vibration on the effective potential of weak-coupling bipolaron in semiconductor quantum dots are studied by using the LLP variational method and quantum statistical theory.The results show that the absolute value of the induced potential of the bipolaron increases with increasing the electron-phonon coupling strength,but decreases with increasing the temperature and the distance of electrons,respectively;the absolute value of the effective potential increases with increasing the radius of the quantum dot,electron-phonon coupling strength and the distance of electrons,respectively,but decreases with increasing the temperature;the temperature and electron-phonon interaction have the important influence on the formation and state properties of the bipolaron:the bipolarons in the bound state are closer and more stable when the electron-phonon coupling strength is larger or the temperature is lower;the confinement potential and coulomb repulsive potential between electrons are unfavorable to the formation of bipolarons in the bound state.
基金supported by the National Natural Fundamental Research Program of China(Grant No.2012CB922103)the National Science Foundation of China(Grant Nos.11375067,11275074,11374116,11204096 and 11405061)the Fundamental Research Funds for the Central Universities HUST(Grant No.2014QN193)
文摘Recently, cavity optomechanics has become a rapidly developing research field exploring the coupling between the optical field and mechanical oscillation. Cavity optomechanical systems were predicted to exhibit rich and nontrivial effects due to the nonlinear optomechanical interaction. However, most progress during the past years have focused on the linearization of the optomechanical interaction, which ignored the intrinsic nonlinear nature of the optomechanical coupling. Exploring nonlinear optomechanical interaction is of growing interest in both classical and quantum mechanisms, and nonlinear optomechanical interaction has emerged as an important new frontier in cavity optomechanics. It enables many applications ranging from single-photon sources to generation of nonclassical states. Here, we give a brief review of these developments and discuss some of the current challenges in this field.
