Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, res...Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, respectively. Heats of formation for the two C4N12O4 isomers have been estimated in this paper, indicating they would be reasonable candidates for high energy density materials.展开更多
针对现有的13.56 MHz NFC(Near Field Communication)天线因结构而引起回波损耗偏高的问题,设计了一种工作在13.56 MHz的近场通信天线,通过优化天线结构,有效降低了天线的回波损耗。使用Ansoft HFSS(High Frequency Structure Simulator...针对现有的13.56 MHz NFC(Near Field Communication)天线因结构而引起回波损耗偏高的问题,设计了一种工作在13.56 MHz的近场通信天线,通过优化天线结构,有效降低了天线的回波损耗。使用Ansoft HFSS(High Frequency Structure Simulator)进行天线模型的设计以及仿真分析,对NFC天线的3大结构参数(天线边长L_x、线间距S和线径W)进行了仿真分析探究,最后得到以13.56 MHz为中心频率的最优天线结构参数,即L_x=40 mm,S=1 mm和W=0.5 mm。在上述天线结构参数下,优于已有的NFC天线(回波损耗为-22.2 d B),其回波损耗降低至-28.8 d B,-10 d B以下的带宽为0.8 MHz。展开更多
In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high...In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.展开更多
基金This work was supported by the Natural Science Foundation of Shandong Province (Y2002G11)
文摘Geometries, energies, and vibrational frequencies for two C4N12O4 isomers with pagodane- and isopagodane-like structures have been calculated at the B3LYP/6-31G＊ level.Isomers 1 and 2 are of D2h and D2d symmetry, respectively. Heats of formation for the two C4N12O4 isomers have been estimated in this paper, indicating they would be reasonable candidates for high energy density materials.
文摘针对现有的13.56 MHz NFC(Near Field Communication)天线因结构而引起回波损耗偏高的问题,设计了一种工作在13.56 MHz的近场通信天线,通过优化天线结构,有效降低了天线的回波损耗。使用Ansoft HFSS(High Frequency Structure Simulator)进行天线模型的设计以及仿真分析,对NFC天线的3大结构参数(天线边长L_x、线间距S和线径W)进行了仿真分析探究,最后得到以13.56 MHz为中心频率的最优天线结构参数,即L_x=40 mm,S=1 mm和W=0.5 mm。在上述天线结构参数下,优于已有的NFC天线(回波损耗为-22.2 d B),其回波损耗降低至-28.8 d B,-10 d B以下的带宽为0.8 MHz。
基金supported by the Chinese PLA General Armament Department under Grant No.51318020305
文摘In recent years, microstrip antennas have been more widely applied in satellite communications, mobile phones, unmanned aerial vehicle （UAV）, and weapons. A micro-electro-mechanical systems-based （MEMS-based） high-resistance silicon C-band microstrip antenna array has been designed for the intelligent ammunition. The center frequency is 4.5 GHz. A cavity has been designed in substrate to reduce the dielectric constant of silicon and high-resistance silicon has been used as the material of substrate to improve the gain of antenna. It is very easy to be manufactured by using MEMS technology because of the improved structure of the antenna. The results show that the gain of the antenna is 8 dB and voltage standing wave ratio （VSWR） is less than 2 by the analysis and simulation in high freauencv structure simulator （HFSS）.
