共查询到19条相似文献,搜索用时 125 毫秒
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冷阴极磁控管是一种性价比很高的可靠微波源,它具有瞬时启动、寿命长、可靠性高、系统容易实现小型化的优点。选用钯钡合金和难熔金属钽作为冷阴极材料,钽环作为一次发射体,由场致发射提供一次电子,钯钡合金为二次发射体,钯钡合金在一次电子的轰击下产生二次电子,两者提供磁控管阴阳极电流,实现磁控管正常振荡。从理论上详细分析了钽环厚度和钯钡合金温度对冷阴极启动特性的影响,基于理论分析结果,开展不同钽环厚度和阴极温度条件下磁控管工作性能研究,最终选用厚度为0.05 mm 的钽环作为冷阴极一次发射体,阴极工作温度在315~836 益之间,成功研制输出功率20 kW的Ka 波段冷阴极磁控管,冷启动稳定时间小于5 s,工作寿命超过500 h 相似文献
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在磁控管及其它M型微波器件中,管内阴极的电子回轰和二次电子发射是其固有的本质特性,这是与O型器件电子枪中阴极的电子发射存在着本质的区别。这就为在M型微波器件中釆用冷阴极提供了可能性,磁控管及其它M型微波器件中若干管型已成功地釆用了冷阴极,而且工作正常,这就充分说明了这一预测的正确性。 相似文献
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叙述了离子束辅助镀膜的特点。对冷阴极和热阴极两种离子源作了比较。论述了冷阴极离子源及其在真空镀膜中的应用。 相似文献
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一、一般情况近年来有关微波器件的阴极热子研制的资料发表得比较少,从电子管工艺技术会议会议录上看,有关阴极热子的文章逐次减少,尽管如此,这几年来已大量应用于器件的热阴极仍有不少工艺上的改进,性能上的提高,68年后又研制出了一些新的类型的阴极,例如钨酸盐阴极,用于正交场放大器的二次发射冷阴极进入了深入研究的阶段,进展比较大的要数半导体发射体,它由于引入了负电子亲合力的概念得到了新的突破,开始迈向实用阶段。 相似文献
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阴极预群聚技术对磁控管的振荡建立过程具有显著的影响,但其作用机理仍然需要进行深入研究。本文对采用角向均匀分布的圆柱形多发射体阴极进行数值模拟,分析了互作用空间场分布及空间电子的运动规律,揭示了多发射体阴极与实体圆柱体阴极在磁控管的起振过程中存在显著差异。多发射体阴极的静电场角向分量与偏置磁场引入的洛伦兹力增强了初始阴极发射的电子向阳极漂移的能力。多阴极磁控管电子轮辐的外边缘更贴近阳极表面,群聚的电子在角向上具有周期性连续变化的速度分布,使得电子与高频场的能量交互更加充分。引入阴极预群聚技术的五阴极磁控管具有起振时间快、输出功率大、效率高等优点,从空间电场分布规律可知,阴极预群聚技术可降低布里渊半径,减少空间电荷对磁控管输出性能的影响。 相似文献
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D. M. Vavriv V. D. Naumenko V. O. Markov 《Radioelectronics and Communications Systems》2018,61(7):283-291
Spatial-harmonic magnetrons with cold secondary-emission cathode are efficient high-power sources throughout the millimeter wavelength band. In this paper, resent advances in design, modeling, and fabrication of such magnetrons are described. Low-voltage magnetrons, sub-THz tubes, and magnetrons with metamaterial anode structure are described to illustrate these advances. The issue of the lifetime of the magnetrons with a cold secondary-emission cathode is also addressed. The main problems related with the usage of an auxiliary cathode in such tubes are considered and alternative solutions are discussed. Potentials for further improving the performance of spatial-harmonic magnetrons are analyzed as well. 相似文献
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用射频噪声法测出了低气压放电灯(荧光灯、紧凑型节能灯、紫外杀菌灯等)阴极的零场发射电流,进而研究了阴极温度和阴极零场发射之间的变化规律,最后,得到了一种比较简单、方便、实用的测试阴极发射特性的方法。 相似文献
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Schunemann K. Sosnytskiy S.V. Vavriv D.M. 《Electron Devices, IEEE Transactions on》2001,48(5):993-998
A self-consistent mathematical model of the spatial-harmonic magnetron (SHM), with cold secondary-emission cathode is proposed for investigating steady-state processes. Characteristic features of modeling space charge effects, secondary emission, and nonlinear electron-wave interaction are described. Illustrative examples of simulations are given in order to show peculiarities of the operation of the SHM as compared to conventional magnetrons. Multi-stable states of the magnetron are described. Results of simulations are compared with experimental data for an 8-mm-wave magnetron 相似文献
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《Electron Devices, IEEE Transactions on》2006,53(8):1929-1936
A magnetron with a metallic cathode shield on the high-voltage (HV) input side is newly designed for the purpose of reducing the spurious noise generated from an oven magnetron. In this paper, it was experimentally found that the newly designed magnetron suppressed the sideband noise around the carrier frequency up to 10 dB, compared to the conventional magnetron. Moreover, both the spurious noise in the high frequency bands (4–14 GHz) and the line noise in the low frequency bands ($sim$ 1 GHz) from the newly designed magnetron were reduced up to 30 dB, compared to the conventional one. It was also found that a cathode shield attached to only the HV input side was more effective than the cathode shields attached to both the HV input side and the RF output side, with respect to the noise reduction. The thermionic emission from the cathode filament and the motions of the electrons in a magnetron are discussed in investigating the noise-reduction mechanisms. 相似文献
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介绍了一种新型的纳米薄膜钪钨阴极,该阴极在1000℃(亮度温度)可以提供至少150A/cm^2的拐点电流密度。同时作者指出:含钪阴极的发射机制倾向于热电子发射机制还是“场助热电子发射”机制主要取决于阴极表面发射小岛的形成和维持。 相似文献
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本文对2 kW连续波磁控管钍钨阴极出现的失效现象进行分析,归纳问题,制定改进措施,分析阴极工作过程,得到了长寿命高可靠的阴极,具有良好的发展前景。 相似文献