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1.
对比分析了几种可输出圆波导TE01模激励器的仿真设计结果。结果表明,利用行波功分结构实现矩形波导TE10模到4路矩形波导TE10模的等幅同相功分,进而合成转换成圆波导TE01模的转换过程,可在较宽的频带范围内,实现圆波导TE01模的高效激励。以中心频率9.40 GHz仿真设计的圆波导TE01模激励器,在中心频率上的传输效率超过99.9%;在9.08~9.61 GHz的频率范围内,传输效率大于99%。实验测量结果表明,所加工激励器在较宽的频带范围内,传输损耗优于-0.2 dB,与仿真结果的差异主要来自于波导壁面的欧姆损耗和波同转换结构;器件工作频带内平坦特性良好,有利于开展测量工作。 相似文献
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现用于4G基站的介质腔体滤波器都采用TE01δ模介质谐振腔,虽然其品质因数Q值很高,但体积较大。为了小型化介质腔体滤波器,创新性地使用了TM010模介质谐振腔,虽然其Q值比较低,但同样能满足高带外抑制的要求。对TM010模介质谐振腔的端口耦合和两腔之间的磁耦合、电耦合进行分析研究,创新性地使用了介质窗的形式产生电耦合,避免了使用飞杆,易于加工,降低制造成本。最后设计了一个8腔TM010模准椭圆函数介质腔体带通滤波器,在通带(TD-LTE频带,2570~2620 MHz)两端分别设计两个传输零点以提高带外抑制。调试结果表明,TM010模介质腔体滤波器不仅能满足低插损、高带外抑制的要求,而且其体积大幅度缩小。 相似文献
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在谐振腔设计过程中, 谐振腔的品质因数以及谐振频率都是需要考虑的关键因素. 传统的方法是通过减小谐振腔的尺寸或者利用高次模来提高谐振腔的谐振频率, 但是由于两种方法都有其局限性, 导致设计结果并不理想. 通过理论计算与模拟仿真相结合的方法, 对影响谐振腔谐振频率的因素进行分析, 得出了填充介质的材料属性与谐振腔谐振频率的关系. 理论计算显示: 当用“左手介质”作为谐振腔的填充物质时, 可以在不改变谐振腔尺寸的基础上提高谐振频率. 高频结构仿真器(high frequency structure simulator)的仿真数据也证明了以上结果, 从而得出谐振腔的谐振频率可以不受谐振腔尺寸的限制. 相较于传统理论而言, 研究结论有进一步的发展, 为探索和设计新颖的谐振腔提供了理论依据. 相似文献
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在波束波导和反射面天线的馈源应用中, 为了产生低副瓣且方向图等化的高斯波束, 需要将高功率微波转换为准高斯模HE11模辐射. 本文利用弯曲圆波导可同时从TM01模产生TE11模和TM11模的原理, 提出了采用双弯曲过模圆波导结构直接将TM01转换为HE11的模式变换器, 避免了常规微波领域中首先将TM01转换为TE11再用波纹式或半径渐变式TE11-HE11转换器转换为准高斯波束功率容量不足或尺寸过长的不足. 基于模式耦合理论和Taguchi优化算法对模式变换器的弯曲半径、相移直端长度及引入位置进行了优化, 使输出的TE11和TM11成一定比率, 以组成HE11模式, 并对设计的模式变换器进行了全电磁波仿真分析, 结果表明输出波束的标量高斯含量在9.05–9.8 GHz范围内均高于99%, 理论功率容量可达4.5 GW.
关键词:
高功率微波
模式耦合理论
Taguchi优化算法
模式变换器 相似文献
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基于不规则波导模式匹配法以及缓变波导中电磁波模式耦合理论,研究了一种W波段圆波导TE62模式激励器. 该波导模式激励器采用矩形波导TE10模式通过侧壁耦合馈入同轴波导,利用同轴波导的选模特性激励TE61模式;随后利用轴向半径周期微扰的圆波导实现TE61–TE62模式变换. 文中推导了矩形-同轴波导模式匹配理论,系统研究了波导结构缓变参数对模式变换效率的影响,完成了模式变换器的优化仿真设计,数值计算结果表明:中心频率处TE62模式的转换效率为94.5%,纯度为98.16%,效率85%以上带宽达到1 GHz,能够满足回旋管冷测的要求.
关键词:
同轴波导
模式变换
耦合模理论
半径微扰 相似文献
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通过棱镜耦合激发非对称金属包覆介质波导结构中的TE0导波模式, 利用两束TE0模的干涉从理论上实现了周期可调的亚波长光栅刻写. 分析了TE0模式的色散关系, 刻写亚波长光栅的周期与激发光源、棱镜折射率、光刻胶薄膜厚度及折射率之间的关系. 用有限元方法数值模拟了金属薄膜、光刻胶薄膜和空气多层结构中TE0导模的干涉场分布. 研究发现, 激发光源波长越短, TE0 模干涉刻写的亚波长光栅周期越小; 光刻胶越厚, 刻写的亚波长光栅周期越小; 高折射率光刻胶有利于更小周期亚波长光栅的刻写. 相较于表面等离子体干涉光刻, 基于TE0 模的干涉可在厚光刻胶条件下通过改变激发光源、棱镜折射率、光刻胶材料折射率、特别是光刻胶薄膜的厚度等多种方式实现对亚波长光栅周期的有效调控. 相似文献
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基于伴随优化设计算法逆向设计了一种高集成度硅基分模器。通过优化设计得到横电模TE0和TE1双模分模器的尺寸仅为5.5μm×4μm,其可在不改变模阶数的情况下实现模式高效分离。理论结果显示:当输入TE0模式时,中心波长处的插入损耗和串扰分别为0.14 dB和-23.8 dB;当输入TE1模式时,插入损耗和串扰分别为0.48 dB和-22.45 dB;工作带宽覆盖150 nm时,TE0和TE1模式的插入损耗分别低于0.44 dB和1.16 dB。基于全矢量三维有限时域差分法分析了±15 nm制备容差,两种模式的插入损耗低于0.79 dB,串扰低于-18.37 dB。所提出的紧凑型硅基分模器可应用于片上模分复用系统,为大容量片上光通信和光互联提供可行器件。 相似文献
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Numerical Simulation and Analysis of a New Type of Complex Cavity for Gyrotron Applications 总被引:1,自引:0,他引:1
Jirun Luo Wei Guo Min Zhu 《International Journal of Infrared and Millimeter Waves》2005,26(12):1703-1711
A new type of complex cavity structure is used to improve the selectivity of modes in gyrotron resonant cavity with a rational
position of inter-cavity wall and the shape of coupling holes between inter- and outer-cavities. The resonant characteristics
of the complex cavity operating in TE021/TE031 mode at Ka frequency band are simulated and analyzed with Ansoft HFSS code, which shows that mode competition can effectively
be alleviated with the cavity structure and it may be useful to the formation of clustered-cavity for extending interaction
frequency bandwidth. 相似文献
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分析了不同宽边情况下对滤波器加工精度的影响,分析结果表明对于不同频段的滤波器,需要选择合适的谐振腔的宽边才能达到较好的性能,同时分析了不同谐振模式的滤波器对加工精度的影响,分析表明,对于太赫兹频段滤波器,选用TE101谐振模式时存在腔体长度会比波导的宽边小很多的情况,而选用高阶谐振模式不但可以提高滤波器的品质因数Q值,减少损耗,同时也能在一定程度上降低滤波器对加工精度的要求。最后以0.34 THz 4阶带通滤波器为例验证此方法的正确性,测试表明该滤波器最低损耗为-0.73 dB,在0.335~0.349 THz范围内损耗在-2 dB以内。 相似文献
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We design a single-ridged coaxial hybrid coupler which excites a TE011 mode of high mode content in a cylindrical cavity, resonating at 28.2GHz. The coupler consists of a WR-28 rectangular waveguide, a coaxial TEn11 cavity, and a cylindrical TE011 cavity. Both TE311 coaxial cavity and TE411 single-ridged coaxial cavity are analyzed to examine the TE011 mode purity in the central cavity. Mode purity analysis is performed by a field expansion method using Fourier-Bessel orthonormal basis functions. Numerical calculations predict that the TE411 single-ridged coaxial cavity excites the TE011 mode with mode purity of 98.6%, which is improved by 3% higher compared with the TE311 coaxial cavity. Measurements on the single-ridged coaxial coupler show a resonant frequency at 28.078GHz and ohmic and external Qs of 1560, 473 respectively, which are in good agreement with the simulated results of a 3-D finite element electromagnetic code. 相似文献
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将电子注视为等离子体柱,从填充等离子体柱的谐振腔的物理模型出发,推导了圆柱腔填充中心电子注时TM0m0模式的特征方程,并重点分析了填充电子注的圆柱腔中TM010模式和TM020模式的谐振频率和电磁场分布随等离子频率的变化情况。研究结果表明,随着电子注的等离子体频率不断增大,谐振频率也不断增大,谐振腔内电场和磁场的分布也随之发生改变。当电子注的等离子体频率超过谐振腔的谐振频率时,谐振腔内的电磁场分布将发生很大的变化,出现了电子注内外电场方向相反和趋肤效应等现象。 相似文献
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Yonggang Wu Zihuan Xia Zhenhua Wang Renchen Liu Pinglin Tang Gang Lv Heyun Wu 《Optics Communications》2012,285(12):2840-2845
A perpendicular dual-grating (PDG) guided-mode resonance filter was constructed by placing two identical waveguide gratings close to and their grooves perpendicular to each other. Multilayer waveguide theory was used to estimate the resonant wavelength for the TE and TM polarization incidences, and the rigorous coupled wave analysis (RCWA) was used to investigate the resonant wavelength, the lineshape and linewidth of the resonant peaks for arbitrary polarization incidences. The filter presents identical spectral characteristics for normally incident wave with arbitrary polarization. The separation of the resonant reflection peaks corresponding to the TE0 and TM0 split modes were realized by properly selecting the geometrical and material parameters of the grating layers and the waveguide layers. Measurement of the nano air gap between 0 and 0.4 p by determining one of the two resonant reflection peaks of the TE0/TM0 split modes was achieved without being interfered by the TM0/TE0 split modes. 相似文献
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In this study, a high power coupler designed for a tunable planar cavity is experimentally tested. The cavity consists of a periodical vane-type structure, of which the height of the vane can be mechanically adjusted so that the resonance frequency can be fine tuned. The cavity is designed to be operated at mode and resonant at 2.45 GHz. The high power coupler is composed of a rectangular waveguide and a cylindrical ceramic rod with tapered ends. One end of the ceramic rod is intruded into the gap between two vanes of the cavity. Through this coupler, the TE10 mode of the rectangular waveguide is converted into the TE11 mode of the ceramic rod and then couples to the TEM mode in the gap between vanes of the cavity. Experimental results show that a microwave power up to 5 kW can be effectively transmitted to excite the mode of the cavity . This cavity can be used to excite large area plasmas 相似文献
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Joaquim J. Barroso Pedro J. Castro Joaquim P. Leite Neto 《International Journal of Infrared and Millimeter Waves》2003,24(1):79-86
We present a method for measuring the electrical conductivity of metallic materials that relies on the ratio of two loaded Q factors, QR/QX, with QR corresponding to a TE011-mode reference cavity made of aluminum, and QX the Q that results upon replacing the aluminum plate with the one fabricated from the material to be examined. Electrical conductivity is mathematically inferred from the ratio QR/QX where the loaded Q factors are measured by using the transmission-type method. Within a 3.0 percent accuracy, conductivities determined at 8.7 GHz for electrolytic copper (5.6 times 107 S/m) and brass (1.6 times 107 S/m) show to be in good agreement with those reported in the literature. 相似文献
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针对传统Helmholtz水声换能器设计中刚性壁假设的局限性,将Helmholtz腔体的弹性计入到液腔谐振频率计算中,实现低频弹性Helmholtz水声换能器液腔谐振频率精确设计.基于细长圆柱壳腔体的低频集中参数模型,导出了腔体弹性引入的附加声阻抗表达式,得到了弹性壁条件下Helmholtz水声换能器等效电路图,给出了考虑了末端修正的弹性壁Helmholtz共振腔液腔谐振频率计算公式.利用ANSYS软件建立了算例模型,仿真分析了不同材质、半径、长度时的Helmholtz共振腔液腔谐振频率.结果对比表明弹性理论值与仿真值符合得很好,相比起传统的刚性壁理论计算结果,本文的弹性壁理论得出的液腔谐振频率值有所降低,与真实情况更加接近.本文的结论可以为精确设计低频弹性Helmholtz水声换能器提供理论支持. 相似文献
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T. Idehara K. Yoshida N. Nishida I. Ogawa M. L. Pereyaslavets T. Tatsukawa 《International Journal of Infrared and Millimeter Waves》1998,19(6):793-801
The first cw operation of our submillimeter wave gyrotron (Gyrotron FU IV) using a 12 T superconducting magnet has been successfully carried out. Output power is more than 20 W at a frequency of 301 GHz in the TE031 resonant cavity mode. Time-resolved frequency measurement s shows that the frequency fluctuation of the gyrotron output is smaller than 2 MHz. This frequency fluctuation is mainly due to the fluctuation in the output voltage of the power supply. 相似文献