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本文运用场匹配法对具有任意位错的双排矩形栅慢波结构的场分布、色散特性及耦合阻抗进行了研究.研究结果表明,场匹配法推导的色散特性与仿真软件CST和HFSS计算的结果完全一致,耦合阻抗介于CST和HFSS之间.在此基础上,详细研究了上下两排系统之间位错对色散特性及耦合阻抗的影响.当位错严格为半个周期时,第一阻带消失,第一个模式最高截止频率与第二个模式最低截止频率重叠,发生简并;当位错为0.45倍周期时,在保证耦合阻抗不变的情况下,基模的通带虽降低了2.8GHz,但阻带却增大了7.9GHz,从而可以有效避免简并及模式竞争的发生. 相似文献
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将任意形状槽的连续轮廓近似用一系列相连的矩形阶梯近似,利用各阶梯面上导纳的匹配,以及槽与互作用区边界场的连续与匹配条件,获得了具有任意槽的矩形波导栅慢波结构的色散方程和耦合阻抗的表达式,并进行理论上的验证.加工制作了矩形槽波导栅模型,冷测表明理论值与测量值相吻合.分别求解几种特殊槽形矩形波导栅慢波结构的色散特性及耦合阻抗,其中,三角形结构的色散和耦合阻抗均最弱,而倒梯形结构色散最强,耦合阻抗最大.
关键词:
矩形波导栅
任意槽
色散特性
慢波结构 相似文献
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本文基于一种阶梯槽交错双栅周期慢波结构模型,获得了该结构中的电磁场分布公式.通过场匹配方法,求出了该结构的高频色散方程和耦合阻抗表达式.以W波段行波管用的阶梯槽交错双栅为例,利用本文公式和CST-MWS电磁软件比较计算了色散和耦合阻抗特性,分析了阶梯尺寸参数对高频特性(基模色散、+1次空间谐波归一化相速和耦合阻抗)的影响.结果表明,理论和CST-MWS软件模拟有很好的一致性;相对矩形交错双栅,改善了色散特性,拓展了基模带宽,同时具有足够大的耦合阻抗和适合工程应用的机械强度,在一定程度上可以弥补矩形交错双栅周期慢波结构的不足. 相似文献
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本文建立了Chodorow型耦合腔慢波结构的解析模型, 利用并矢格林函数结合矩量法求解了场匹配方程, 给出了色散方程和耦合阻抗的计算式, 并数值计算出一个X波段Chodorow型慢波结构的高频特性. 结果表明, 本文方法的色散特性以及耦合阻抗与仿真软件HFSS计算的结果有很好的一致性, 且计算效率更高, 同时精度远高于等效电路法, 对工程设计有好的参考价值.
关键词:
Chodorow型耦合腔慢波结构
色散特性
耦合阻抗
场匹配 相似文献
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用阶梯近似的方法分析任意槽形加载的圆波导慢波系统,利用各阶梯相邻面的导纳匹配条件 以及中心互作用区与加载区的场匹配条件,获得了任意槽形加载周期慢波结构的统一色散方 程. 利用该色散方程,得到色散特性与CST MWS仿真软件模拟结果良好符合. 分别求解几种 特殊槽形加载慢波结构的色散特性及耦合阻抗,其中,三角形结构色散和耦合阻抗均最弱, 而倒梯形结构色散最强,耦合阻抗最大.
关键词:
任意槽形
慢波结构
色散特性
行波管 相似文献
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Theoretical results are given for pressure and intensity in the acoustical field produced by rectangular ultrasonic transducers. Comparison between the fields of square, circular and rectangular transducers is made showing that the field of a rectangular transducer, by comparison with that produced by square and circular transducers, may be divided into three zones rather than two: the very nearfield, the nearfield and the farfield. Some experimental results are shown confirming the general shape of the predicted curves. Emphasis is put on the difficulty of interpreting quantitative ultrasonic results with rectangular probes. 相似文献
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Longitudinal optical phonon effect on Wannier excitons in polar rectangular quantum wires is studied by a variational approach. The binding energy is calculated and the numerical results for several II-VI and III-V compound semiconductor rectangular quantum wires are given. The results show that the phonon effect reduces the binding energy and cannot be neglected. The phonon contribution to the binding energy is sensitive to the size of the rectangular quantum wire section, and increases with decreasing section area. The results for the GaAs rectangular quantum wires coincide with the experimental results. The calculated binding energy and the phonon effect in II-VI QWWs are both stronger than those in III-V compound systems, and the results for ZnSe QWW are qualitatively in agreement with the experiments. 相似文献
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V. N. Pochernyaev 《Radiophysics and Quantum Electronics》1996,39(7):597-601
We propose an analytical solution of the problem of determination of external parameters of T-shaped E and H tees on partially filled rectangular waveguides. The solution is tested for a particular case of E and H tees on hollow rectangular waveguides and compared with the known solution obtained by the numerical method. Calculated results show good agreement. Numeral results are given for tees on partially filled rectangular waveguides.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 39, No. 7, pp. 901–909, July, 1996. 相似文献
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根据半经典闭合轨道理论研究了矩形腔对氢负离子的光剥离进程的影响,利用反射定律分析矩形腔中与光剥离截面相联系的剥离电子运动的闭合轨道,推导出该体系下的光剥离截面公式,在线性极化光的作用下,研究了腔的尺寸对光剥离截面的影响,并将其与麻志君等用量子力学方法研究的结果进行对比.结果表明:矩形腔的存在及其大小对光剥离截面中由闭合轨道相联系的返回波与波源函数发生干涉引起的振荡有很大影响,且振荡曲线随着矩形腔的尺寸变化明显;当激光极化方向沿着x轴或者y轴时,半经典方法与量子力学方法的结果一致,当激光极化方向沿着Z轴时,由于矩形腔在z轴上对光剥离截面不作用,采用半经典方法光剥离截面与无场的情况相同,但是采用量子力学方法,其结果中却出现振荡,表明半经典方法研究此体系结果更准确.研究结果可对研究负离子光剥离以及外腔中的电子输运问题提供参考. 相似文献
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基于模式匹配法建立了矩形槽同轴布拉格结构的全波耦合分析模型, 推导出了不同模式反射率和传输率的计算式, 并采用公开报道的实验数据验证了该理论模型. 在此基础上就本文理论与其他相关的理论方法进行了比较, 发现以前的理论近似模型由于忽略了矩形槽中的消失模而使传输率的频率响应曲线发生偏差. 本文建立的理论方法有望为矩形槽同轴布拉格结构的特性研究和工程实践提供一种理论分析手段.
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同轴布拉格结构
矩形波纹
模式匹配法
模式耦合 相似文献
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This paper presents a method to evaluate the capacitance and the surface charge distributions of a satellite modeled as a structure consisting of a rectangular cuboid with two coplanar rectangular plates. The Charges accumulate on the satellite surfaces result destructive electrostatic discharges (ESD). Integral equations are formed by relating the unknown charge density on the metallic cuboid and the two rectangular plates to the potential on the surface of these bodies. The integral equations are solved using the Method of Moments (MoM) based on pulse function as basis functions and delta functions as testing functions. In order to apply MoM, the surfaces of the metallic bodies are discretized by using non-uniform rectangular subsections. The numerical data on capacitance of this structure have been presented. The key results are that the computational method is validated by computing the capacitance of a cuboid to be 73.46 pF/m, which is consistent with previous works. Faster convergence and shorter computational time are achieved using non-uniform subsections. And, as expected, the surface charge density diminishes at joints where the plates connect to the cuboid. 相似文献
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The Fano resonances of the asymmetric dimers of gold nanowires with square and rectangular sections are investigated by using the finite-difference time-domain (FDTD) method. It is found that the Fano resonance peak can be switched on and off by laying or removing the rectangular section nanowire aside the square section one. There is only one dipole resonance mode of a single gold nanowire with a square section on the dielectric substrate, and it redshifts obviously accompanied with the FWHM being broadened along with the side width of the nanowire increasing. A Fano resonance appears when another gold nanowire with the rectangular section is laid aside the one with a square section. The peak value and FWHM of the Fano resonance mode increase obviously with the distance between the two nanowires getting larger. Meanwhile, it can be modulated by the height of the rectangular section nanowire. In addition, they can be regulated by the width and rotating angle of the rectangular section nanowire, but the peak value stays the same. The mechanisms for these behaviors are associated with the interaction of the superradiant and subradiant modes, and the corresponding electric field distributions are plotted to verify this. It is expected that the results will be useful for the design of wavelength biosensing and other new optical devices. 相似文献
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The spectral characteristics of the hole photocurrent in plasmon photodetectors based on Ge/Si heterostructures with Ge quantum dots combined with regular arrays of subwavelength apertures of various shapes in a gold film on the semiconductor surface are investigated. Dispersion relations characterizing the propagation of surface plasmon waves along the metal–semiconductor interface are determined from the dependences of the photocurrent on the angle of incidence of light. It is established that the plasmonic enhancement of the photocurrent in rectangular aperture array is suppressed as compared to that in circular and square aperture arrays. It is found that, in hybrid structures with rectangular apertures, there exists a range of wave vectors where the energy of surface plasmons is independent of the wave vector of incident radiation. The results are explained by the excitation of dipole modes localized at rectangular apertures with a large aspect ratio by light waves. 相似文献