随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出...随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出了一种针对Super C Band传输的EDFA结构,基于Giles模型,分析了EDFA在Super C Band的特性,利用多级泵浦机制,设计了一种可以在Super C Band范围内进行放大的EDFA。结果表明,在-9.3 dBm入光时,该EDFA可以实现26 dB的平坦增益,16.7 dBm的输出功率,此时噪声指数小于5 dB,Ripple小于0.1 dB。并且根据需要,在入光处于-15.0~-3.5 dBm范围内时,通过调节泵浦功率与可调衰减器,均能够实现7~26 dB的可调增益。该EDFA可应用于5G传输和数据中心之间光纤通信等场合。展开更多
A mobile C-band dual polarimetric weather radar J type （PCDJ）, which adopts simultaneous transmission and simultaneous reception （STSR） of horizontally and vertically polarized signals, was first developed in Chin...A mobile C-band dual polarimetric weather radar J type （PCDJ）, which adopts simultaneous transmission and simultaneous reception （STSR） of horizontally and vertically polarized signals, was first developed in China in 2008. It was deployed in the radar observation plan in the South China Heavy Rainfall Experiment （SCHeREX） in the summer of 2008 and 2009, as well as in Tropical Western Pacific Ocean Observation Experiments and Research on the Predictability of High Impact Weather Events from 2008 to 2010 in China （TWPOR）. Using the observation data collected in these experiments, the radar systematic error and its sources were analyzed in depth. Meanwhile an algorithm that can smooth differential propagation phase （~Dp） for estimating the high-resolution specific differential phase （KDP） was developed. After attenuation correction of reflectivity in horizontal polarization （ZH） and differential reflectivity （ZDR） of PCDJ radar by means of KDP, the data quality was improved significantly. Using quality-controlled radar data, quantitative rainfall estimation was performed, and the resutls were compared with rain-gauge measurements. A synthetic ZH /KDp-based method was analyzed. The results the traditional ZH-based method when the rain suggest that the synthetic method has the advantage over rate is 〉5 mm h^-1. The more intensive the rain rates, the higher accuracy of the estimation.展开更多
A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF ...A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF pulse compressor cavities,so that the power gain factor can be 3.2,which is supposed to multiply the RF power from 50 MW to 1 60 MW.In this paper,we report our work on C-band RF pulse compressor,namely the design simulation and cold test results.展开更多
The physical design and cooling test of a C-band 2MeV standing wave （SW） accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section ...The physical design and cooling test of a C-band 2MeV standing wave （SW） accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM （full width at half maximum of density distribution） is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3：9：10.展开更多
The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by Intern...The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by International Telecommunication Union. The X-band is used for terrestrial broadband communication, radar applications, and portions of the X-band are assigned for deep space telecommunications. In this paper, a design of 4 × 1 Ultra Wide Band (UWB) antenna array for C-band and X-band applications is introduced. Metamaterial sixteen-unit cells are incorporated into each antenna element for radiation characteristics enhancement purposes. Permeability and permittivity of metamaterial unit cells are obtained all over the operating bandwidth. UWB unequal power divider is used to feed the proposed four elements antenna array based on Chebyshev excitation method. The proposed antenna has a suitable 3 dB beam width and gains all over the operating bandwidth which extends from 5.6 GHz to 10.9 GHz. The proposed antenna covers 60% and 72.5% of the C-band and X-band, respectively. The proposed antenna is fabricated, measured, and good agreement is obtained between simulated and measured results. The obtained performance ensures the suitability of the proposed antenna array for C-band and X-band applications.展开更多
文摘随着网络业务流量的增长,通信业务对密集波分复用(DWDM)的性能要求越来越高。为了提高传输效率,传输频谱逐渐向C+L Band传输扩展,Super C Band传输应运而生,但目前与之对应的掺铒光纤放大器(EDFA)相关研究较少。针对这一问题,文章提出了一种针对Super C Band传输的EDFA结构,基于Giles模型,分析了EDFA在Super C Band的特性,利用多级泵浦机制,设计了一种可以在Super C Band范围内进行放大的EDFA。结果表明,在-9.3 dBm入光时,该EDFA可以实现26 dB的平坦增益,16.7 dBm的输出功率,此时噪声指数小于5 dB,Ripple小于0.1 dB。并且根据需要,在入光处于-15.0~-3.5 dBm范围内时,通过调节泵浦功率与可调衰减器,均能够实现7~26 dB的可调增益。该EDFA可应用于5G传输和数据中心之间光纤通信等场合。
基金funded by National Natural Science Foundation of China (Grant Nos. 40975013 and 40975014)Chinese Academy of Meteorological Sciences (CAMS) basic scientific and operational project:Observation and retrieval methods of microphysics and dynamic parameters of cloud and precipitation with multi-wavelength Remote Sensing,SCHeREX and TWPOR
文摘A mobile C-band dual polarimetric weather radar J type （PCDJ）, which adopts simultaneous transmission and simultaneous reception （STSR） of horizontally and vertically polarized signals, was first developed in China in 2008. It was deployed in the radar observation plan in the South China Heavy Rainfall Experiment （SCHeREX） in the summer of 2008 and 2009, as well as in Tropical Western Pacific Ocean Observation Experiments and Research on the Predictability of High Impact Weather Events from 2008 to 2010 in China （TWPOR）. Using the observation data collected in these experiments, the radar systematic error and its sources were analyzed in depth. Meanwhile an algorithm that can smooth differential propagation phase （~Dp） for estimating the high-resolution specific differential phase （KDP） was developed. After attenuation correction of reflectivity in horizontal polarization （ZH） and differential reflectivity （ZDR） of PCDJ radar by means of KDP, the data quality was improved significantly. Using quality-controlled radar data, quantitative rainfall estimation was performed, and the resutls were compared with rain-gauge measurements. A synthetic ZH /KDp-based method was analyzed. The results the traditional ZH-based method when the rain suggest that the synthetic method has the advantage over rate is 〉5 mm h^-1. The more intensive the rain rates, the higher accuracy of the estimation.
基金the Accelerator Laboratory of Tsinghua University for experiment supports
文摘A C-band RF pulse compressor is in development at SINAP It comprises of two resonant cavities,two mode convertors and a 3 dB power divider.TE_(0.1.15)mode is selected for obtaining higher quality factor Q_0 of the RF pulse compressor cavities,so that the power gain factor can be 3.2,which is supposed to multiply the RF power from 50 MW to 1 60 MW.In this paper,we report our work on C-band RF pulse compressor,namely the design simulation and cold test results.
文摘The physical design and cooling test of a C-band 2MeV standing wave （SW） accelerating tube are described in this paper. The designed accelerating structure consists of 3-cell buncher and 4-cell accelerating section with a total length of about 163mm, excited with 1MW magnetron. Dynamic simulation presents that about 150mA beam pulse current and 30% capture efficiency can be achieved. By means of nonlinear Gauss fit on electron transverse distribution, the diameter of beam spot FWHM （full width at half maximum of density distribution） is about 0.55mm. Cooling test results of the accelerating tube show that frequencies of cavities are tuned to 5527MHz and the field distribution of bunching section is about 3：9：10.
文摘The C-band is allocated for commercial telecommunications via satellites. Amateur satellite operations in the frequency range 5.830 to 5.850 GHz for down-links and 5.650 to 5.670 GHz for up-links are allowed by International Telecommunication Union. The X-band is used for terrestrial broadband communication, radar applications, and portions of the X-band are assigned for deep space telecommunications. In this paper, a design of 4 × 1 Ultra Wide Band (UWB) antenna array for C-band and X-band applications is introduced. Metamaterial sixteen-unit cells are incorporated into each antenna element for radiation characteristics enhancement purposes. Permeability and permittivity of metamaterial unit cells are obtained all over the operating bandwidth. UWB unequal power divider is used to feed the proposed four elements antenna array based on Chebyshev excitation method. The proposed antenna has a suitable 3 dB beam width and gains all over the operating bandwidth which extends from 5.6 GHz to 10.9 GHz. The proposed antenna covers 60% and 72.5% of the C-band and X-band, respectively. The proposed antenna is fabricated, measured, and good agreement is obtained between simulated and measured results. The obtained performance ensures the suitability of the proposed antenna array for C-band and X-band applications.
