2411号台风“摩羯”于2024年9月登陆中国东南沿海地区,风云三号D星(FY-3D)微波湿度计(MWHS-II)成功监测到该台风.本研究在天气研究与预报模式数据同化系统(Weather Research and Forecasting model Data Assimilation system,WRFDA)中...2411号台风“摩羯”于2024年9月登陆中国东南沿海地区,风云三号D星(FY-3D)微波湿度计(MWHS-II)成功监测到该台风.本研究在天气研究与预报模式数据同化系统(Weather Research and Forecasting model Data Assimilation system,WRFDA)中构建了晴空条件下FY-3D MWHS-II资料三维变分同化框架,通过设置118 GHz,183 GHz单频段以及双频段联合同化及预报试验方案,系统评估了MWHS-II资料同化对台风“摩羯”的强度、路径及降水预报效果.试验表明,同化FY-3D MWHS-II资料有效提升了分析场质量,对台风强度、路径和降水的预报也产生了积极影响.台风预报方面,同化118 GHz和183 GHz通道对台风路径预报分别改进了17.18%和13.39%,洋面区域的183 GHz同化更使得路径预报改进率达到14.59%;降水预报方面,MWHS-II资料同化显著提升初期24 h内中小雨量级(<25 mm)预报命中率,其中118 GHz通道对强降水(>50 mm)预报表现出独特优势;183 GHz通道的改进效应在24 h后逐步显现,而双频段联合同化方案展现出综合优势,各量级降水的降水分数技能得分(Fractions Skill Scores,FSS)相比控制试验提升显著.FY-3D MWHSII的118 GHz和183 GHz频段在不同预报要素上的差异化改进效果,突显了FY-3D MWHS-II资料在区域台风数值预报中的独特应用价值及应用潜力.展开更多
In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the ...In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the rapid determination of optimal embedding impedance for diodes across a specific bandwidth to achieve maximum efficiency through harmonic balance simulations.By optimizing the linear matching circuit with the optimal embedding impedance,the method effectively segregates the simulation of the linear segments from the nonlinear segments in the frequency multiplier circuit,substantially improving the speed of simulations.The design of on-chip linear matching circuits adopts a modular circuit design strategy,incorporating fixed load resistors to simplify the matching challenge.Utilizing this approach,a 340 GHz frequency doubler was developed and measured.The results demonstrate that,across a bandwidth of 330 GHz to 342 GHz,the efficiency of the doubler remains above 10%,with an input power ranging from 98 mW to 141mW and an output power exceeding 13 mW.Notably,at an input power of 141 mW,a peak output power of 21.8 mW was achieved at 334 GHz,corresponding to an efficiency of 15.8%.展开更多
基金Supported by the Beijing Municipal Science&Technology Commission(Z211100004421012),the Key Reaserch and Development Pro⁃gram of China(2022YFF0605902)。
文摘In this paper,a linear optimization method(LOM)for the design of terahertz circuits is presented,aimed at enhancing the simulation efficacy and reducing the time of the circuit design workflow.This method enables the rapid determination of optimal embedding impedance for diodes across a specific bandwidth to achieve maximum efficiency through harmonic balance simulations.By optimizing the linear matching circuit with the optimal embedding impedance,the method effectively segregates the simulation of the linear segments from the nonlinear segments in the frequency multiplier circuit,substantially improving the speed of simulations.The design of on-chip linear matching circuits adopts a modular circuit design strategy,incorporating fixed load resistors to simplify the matching challenge.Utilizing this approach,a 340 GHz frequency doubler was developed and measured.The results demonstrate that,across a bandwidth of 330 GHz to 342 GHz,the efficiency of the doubler remains above 10%,with an input power ranging from 98 mW to 141mW and an output power exceeding 13 mW.Notably,at an input power of 141 mW,a peak output power of 21.8 mW was achieved at 334 GHz,corresponding to an efficiency of 15.8%.
