用时域有限差分法研究圆柱形谐振器

本文建立了圆柱坐标系下的时域有限差分算法程序，运用处法分析了几种圆柱形谐振器（包括同轴形，圆柱形介质加载和开放式柱形介质谐振器）在各种模式下谐振频率，数值与理论值、实验值进行了比较，表明具有很高的精度，本文还对计算中网格的选取原则进行了探讨；并计算了一种双层介质加载腔的谐振频率，从中得出一些有益的结论。     

圆柱形谐振器谐振频率的数值解法

本文介绍用于微带电路中的圆柱形介质谐振器TE_(01δ)模谐振频率的一种计算方法。应用计算机求解由修正的介质波模型导出的一组超越方程,得出了圆柱形介质谐振器谐振频率的数值解。给出了圆柱形介质谐振器高度、直径比和对应的归一化谐振频率的若干组数据表格,绘制了相应的曲线图。只要给定介质谐振器尺寸,便可以从图表中查出相应的TE_(01δ)模谐振频率,反之亦然。这些图表可供直接设计2～12GHz频段的介质谐振器选用。实验证明,用本方法求出的谐振频率误差总小于2%,当空气间隙较小时,这一误差更小。     

介质谐振器特性的有限元计算

本文应用有限元方法分析和计算了置于空气和不均匀介质中的圆柱形介质谐振器的谐振频率,以及介质谐振器与微带线的耦合参量。计算结果与现有文献的计算结果和实验结果相当吻合。     

小型TM010模介质谐振器滤波器

求解圆形介质杆谐振器的特征方程,得到了谐振模式图。TM_(010)模介质谐振器谐振频率的计算值与测量值相符。对介质杆谐振器的Q值进行了讨论。给出了S波段小型TM_(010)模介质谐振器滤波器的实验结果。     

垫片加载圆柱介质谐振器的谐振频率计算方法

本文利用开波导法对有垫片加载的圆柱型介质谐振器之谐振频率进行了计算,其计算结果与实验吻合，误差小于1％。此方法适宜于实际工程。     

分层同轴介质谐振器谐振频率特性的研究

本文导出了置于无限平行导体板间和置于屏蔽结构中的任意分层同轴介质谐振器的TE、TM模场分量表达式以及求解TE、TM模谐振频率的一般耦合特征方程。对于同轴(l=3层)介质谐振器进行了深入研究和大量计算,得到了同轴(l=3层)介质谐振器的主模和一些高次模的谐振频率随几何尺寸和介质特性变化的关系曲线和数据表。     

介质谐振器带通滤波器的实验研究

──本文对金属屏蔽TM_(010)模介质谐振器的谐振频率进行了理论计算;并就所设计的介质谐振器构成的带通滤波器耦合探针和调谐装置进行了实验研究。     

圆柱形介质谐振器谐振频率的图解法

本文介绍在微带电路中使用圆柱形介质谐振器时,TE_01δ模谐振频率的图解法。这种方法不但简便易行,省去了大量繁冗的数值计算,而且具有一定的准确度。对许多样品的测试表明,用这种方法计算的谐振频率,与实验测试值比较,误差大多在1％范围以内。     

光控介质谐振器的频率调谐

本文对置于金属屏蔽中介质基片上的叠片式介质谐振器进行了分析;给出了光控频率调谐的线性理论公式和叠片式介质谐振器的谐振频率公式。这些公式可用于光控介质谐振器振荡器的理论计算和频率稳定度极高的叠片式介质谐振器的工程设计。     

测量与微带线耦合的介质谐振器特性的自动化技术

本文提出了一种测量与微带线耦合的介质谐振器的谐振频率、有载品质因数和耦合因子的计算机自动控制技术。借助于网络分析仪,以频率为自变量测出该系统复传输系数。计算每一个频率点上的反射系数并进行幅值处理,获得谐振器的特性参数。Q值和耦合因子的误差大约是1％,谐振频率的误差是10~(-6)。     

Rigorous analysis of shielded cylindrical dielectric resonators bydyadic Green's functions

This paper presents a rigorous approach for the calculation of resonant frequencies of a metallic cavity loaded by a dielectric resonator. Tangential fields at the air-dielectric interface are derived from dyadic Green's functions and boundary conditions are applied. Dyadic Green's identity and the boundary element method are used to solve the numerical problem. In order to validate the method, resonant frequencies are calculated for a cylindrical cavity loaded with a dielectric cylinder and compared with available results in the literature. Then resonance is studied for dielectric cylinder in a rectangular cavity. In the case of multiple dielectric resonators in the cavity, the coupling coefficient is computed with an original method based on the use of symmetries     

Study of TE0 and TM0 modes in dielectricresonators by a finite difference time-domain method coupled with thediscrete Fourier transform

An application of a numerical method of finite differences in the time domain (FDTD) coupled with the discrete Fourier transform is presented to determine the resonant frequencies of the TE₀ and TM₀ modes of axially symmetric dielectric resonators closed in a cavity. The technique is conceptually and computationally simple, and it allows access at once to information on the entire modal spectrum by means of the fast Fourier transform (FFT) applied to the time series. The cylindrical cavity dielectrically loaded at the base and the resonant frequency of the TE_01δ mode are analyzed in two systems: a cylindrical cavity with a cylindrical dielectric resonator of variable radius, and the shielded dielectric resonator on a microstrip substrate. The results obtained are compared with the rigorous (exact) theoretical solutions and with experimental results     

Resonant modes in shielded cylindrical ferrite and single-crystaldielectric resonators

The Galerkin-Rayleigh-Ritz method is applied for computing the first few lowest resonant frequencies of cylindrical anisotropic resonators in a cylindrical cavity. The resonators are allowed to have gyromagnetic and uniaxial dielectric anisotropy with respect to the z-axis of the cylinder. Results of computations of the resonant frequencies are compared to exact solutions for many simple resonant structures and to results of experiments for more complicated structures, with good agreement. A new method of measuring permeability tensor components is presented. The method utilizes two parallel-plate cylindrical resonators operating in the HE⁺-/₁₁₁ and H₀₁₁ modes. A method of measuring the permittivity tensor components of single crystals using one parallel-plate cylindrical resonator operating in two different modes is proposed     

Resonant modes in shielded uniaxial-anisotropic dielectric rodresonators

Rigorous field analysis by the mode-matching method is presented for dielectric rod resonators, including such uniaxial dielectrics as sapphire, which are placed between two parallel conducting plates or in a conducting cavity. The wave equations for E_Z and H_Z in a uniaxial anisotropic dielectric medium are derived in a cylindrical coordinate system. Based on these wave equations, the characteristic equations for the two resonator structures are derived and can be used to calculate the resonant frequencies of any resonant mode. Cutoff conditions of the resonant modes are discussed for parallel-plate-type resonators. Resonant frequencies of some lower order modes are calculated for both types of resonator. Mode charts useful for designing the resonators are presented. It is verified that the mode-matching method used commonly for the analysis of isotropic-dielectric resonators can be applied successfully to uniaxial-dielectric resonators     

Accurate Resonant Frequencies of Dielectric Resonators

The applications of dielectric resonators are currently of considerable interest in microwave integrated circuits. The design of a dielectric resonator depends on its natural resonant frequencies. Since exact solutions of dielectric rectangular and cylindrical resonators cannot be rigorously computed a new and more accurate method has been developed to solve this problem. In this method all the surfaces are simultaneously considered as imperfect magnetic walls. Theoretical values agree very well with experimental results. The difference being less than 1 percent.     

A multicomposite, multilayered cylindrical dielectric resonator forapplication in MMIC's

A method, based on the mode matching technique, to study various resonant modes of a multicomposite, multilayered cylindrical dielectric resonator is presented. Dielectric sphere and cone resonators placed in practical environments are investigated. The calculated resonant frequencies show very good agreement compared with the numerical results of the finite difference method for the spherical resonator and with the measured values for the conical resonator, respectively. Experimental investigations show that the conical resonator can be coupled to a circular microstrip line, which has small size at high frequencies and may be integrated together with an oscillator     

蓝宝石谐振体与其回音壁模

本文采用模匹配方法(mode matching method)计算了单轴各向异性圆柱形介质谐振体的回音壁模频率.对一圆柱形蓝宝石单晶体谐振体的实验测量,验证了该模匹配方法能给出精确的回音壁模频率值.     

Generalized multilayer anisotropic dielectric resonators

Modeling of the generalized multilayer cylindrical anisotropic dielectric loaded resonator by a rigorous mode-matching method is presented in this paper. Eigenmodes of the multilayer two parallel-plate waveguides are obtained. By cascading the radial discontinuities of the structure, resonant frequency, field distribution, unloaded Q, and the frequency sensitivity of the resonator are obtained. The method can be used to analyze and design resonators and filters of multilayer structure. The computed results are compared with measured results and with experimental data, and shown to be in good agreement     

Design of Microwave Dielectric Resonators

The resonant frequencies for the fundamental modes in circular cylindrical and rectangular parallelopiped high dielectric resonators have been calculated by computer for a range of values of physical dimensions and relative dielectric constant. The frequency range extends from zero to 50 kMc/s, the relative dielectric constant from 50 to 1800, and physical dimensions from zero to 500 roils. Results are presented in graphical form with frequency plotted vs. resonator length for parametric values of relative dielectric constant and cross-sectional dimensions. A brief review of earlier work with high dielectric resonators is included. Expressions for the resonant frequency and fundamental mode field configurations are given.