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61.
为了开展高功率微波(HPM)馈源输出窗介质击穿实验研究,设计了一种组合型X波段高功率微波(HPM)喇叭馈源击穿实验装置。装置采用变张角喇叭与可移动介质输出窗组合的结构,通过调节变张角喇叭口面与输出窗间的距离,使得介质输出窗内表面电场强度可调。数值模拟结果表明:在满足馈源喇叭驻波比小于1.15,E面和H面基本等化的情况下,当调节变张角喇叭口面与介质输出窗距离在0~400 mm范围内变化时,HPM馈源输出窗上的电场强度变化为32.6~87.0 kV.cm-1,满足了在真空度3×10-3Pa、脉冲宽度20 ns条件下,HPM介质击穿对电场强度变化的要求。根据数值模拟结果,设计加工了HPM介质击穿实验装置,并成功地应用于GW级HPM馈源输出窗介质击穿实验研究。 相似文献
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64.
讨论了微波脉冲通过孔缝线性耦合进入腔体内的研究方法。给出了线性耦合的物理基础,定义了耦合函数,并导出了耦合函数随入射电场极化方向变化的公式。简要描述了数值求解孔缝线性耦合的时域有限差分方法以及修正算法。给出了以矢量网络分析仪HP8510C为主要设备测量耦合函数的实验方法。通过耦合函数的研究,观察到了共振效应和增强效应等现象,给出了微波孔缝耦合发生共振的普适公式。分析了测量探头对耦合函数测量的影响,验证了耦合函数随入射电场方向变化的公式。理论、数值和实验结果符合得较好。 相似文献
65.
Zbyněk Lukeš 《Journal of Molecular Spectroscopy》2007,243(2):227-233
In the paper, an influence of antennas transmitting the electromagnetic wave to the sample cell of a millimeter-wave molecular spectrometer on the properties of the whole device is discussed. A conventional rectangular horn antenna is considered as the reference antenna, and a double ridge horn antenna is designed, modeled and optimized in order to improve parameters of the spectrometer potentially. A detailed comparison of the reference antenna and the double ridge horn shows that a wider frequency band can be covered by the designed antenna, but the gain achieved is lower. 相似文献
66.
M. T. Chen C. -Y. E. Tong S. Paine R. Blundell 《International Journal of Infrared and Millimeter Waves》1997,18(9):1697-1711
We present measurements of the near-field beam profiles of two corrugated feed horns with center frequencies of 216 and 300
GHz. Both co-polar and cross-polar components of the electric field have been probed across the operation band of the horns.
A full-wave numerical near-field transformation, based on a vector Kirchhoff integral, is implemented to transform the measured
field to the horn aperture for a comparison with the ideal aperture field. From the overlap integral of the transformed and
the ideal field, we conclude that the field radiated by these horns is the HE11 mode, to a purity of better than 99%. 相似文献
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Traditional technique of horn equation solved by transfer matrices as a model of vibration of ultrasonic systems consisting of sectional transducer, horn and load is discussed. Expression of vibration modes as a ratio of solutions of two Schrödinger equations gives better insight to the structure of a transfer matrix and properties of amplitudes of displacement and strain, and enables more systematic search for analytic solutions. Incorrectness of impedance matrix method and of equivalent circuit method on one hand and correctness and advantages of transfer matrix method in avoiding numerical artifacts and revealing the real features of the model on the other hand are demonstrated on examples. Discontinuous dependence of the nth resonant value on parameters of ultrasonic system, recently described in Sturm–Liouville theory, and consequently, a jump from half-wave to full-wave mode, is observed in a transducer model. 相似文献
69.
Zhou G 《Ultrasonics》2000,38(10):979-984
The matrix method for analyzing flexural vibration system is outlined. The displacement, stress and velocity gain of ultrasonic flexural vibration systems are investigated by transfer matrix method. A design method is given for flexural transducer and vibration system. 相似文献
70.
Jorge Teniente Ramón Gonzalo Carlos del Río 《International Journal of Infrared and Millimeter Waves》1999,20(10):1809-1815
In this paper, the design and the measurements of a Gaussian profiled horn antenna for the 11.7-12.2 GHz frequency band for the HISPASAT 1C satellite are presented. The study shows the possibility of improving the electromagnetic and physical features of conventional horn antennas by using Gaussian techniques. 相似文献