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PWM控制回路的设计 被引量:1
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作者 张鸣 张青 《湖北工学院学报》 2004年第3期178-179,182,共3页
围绕三相异步电动机的变频调速,运用电子技术,构造了一种PWM控制模式,并以此为依据实现了高频率、大范围和精密控制的无级调速.
关键词 PWM控制回路 三相异步电动机 变频调速 脉冲宽度调制控制 双极性控制
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一种新颖的船用雷达显示系统
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作者 程绍洪 《水产科学》 CAS 北大核心 1998年第5期23-26,共4页
介绍新颖的船用雷达显示系统的工作原理,并对具有特色的电路进行分析和计算。通过维修和测试,归纳了调试的步骤和方法,并对部分电路进行了改进,效果良好。
关键词 时基门 固定距标 波宽度控制 船用雷达
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A Study on the Control of BDSIGPS Self-phase Quadrifilar Helical Antenna for Ship
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作者 SUN Zhen ZHAO Jiansen +3 位作者 WANG Shengzheng XU Tie LIU Wei CHANG Yongmeng 《Journal of Shipping and Ocean Engineering》 2017年第3期108-111,共4页
A reconfigurable, self-phase quadrifilar helical antenna was designed at BDS/GPS frequency band. The impedance, gain and directivity of the antenna were studied by HFSS based on FEM (finite element method) and exper... A reconfigurable, self-phase quadrifilar helical antenna was designed at BDS/GPS frequency band. The impedance, gain and directivity of the antenna were studied by HFSS based on FEM (finite element method) and experiment. Results show the beam width of the main lobe of the pattern can reach over 160° with the help of the load on the top of the antenna. And the power of the side-lobe level is very low. In addition, the quadrifitar helix antenna has excellent right-hand circular polarization performance with a beam width of 180°. Both single-frequency and double-frequency communications can be carried out by the antenna in the ranges between 1.2 and 1.8 GHz, with the bandwidth of each frequency about 60 MHz, the simulating and experimental results are nearly the same. 展开更多
关键词 Quadrifilar helical antenna CONTROLLABILITY BEIDOU FEM
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