电容式RF MEMS谐振器

介绍了应用于通信领域的电容式RF MEMS谐振器及其在通信系统小型化中的优势。对电容式微机械谐振器进行了综合分析,包括基本工作过程分析、基本参数的理论分析及等效电路的分析。介绍了目前几种常用结构的谐振器,包括梳状谐振器、梁式谐振器及盘式谐振器的工作过程和谐振频率的发展空间。重点分析了谐振器的电容间隙及锚这两个重要的结构参数对谐振器性能的影响。最后,对电容式微机械谐振器存在的问题作了总结,对其发展趋势做出展望。     

圆形镜激光介稳共振腔的衍射理论结果

到目前为止,对介稳腔(g1g2=1或g1g2=0)讨论不多用几何光学法计算.指出虚共心腔轴向波型的损耗为零,非轴向波型的偏折损耗比平行平面腔大|r1/r2|=|g2|倍,波面为球面波.文献[2]报导了钕玻璃虚共心腔激光器的输出光束能量小,峰值亮度高,发散角小,光强分布均匀;同时指出几何光学法的局限性,轴向波型的损耗不但不为零,而且比平行平面腔大.输出波面也不可能为纯球面波,因为有边界衍射.本文以衍射理论较全面地研究介稳腔特性.     

固体激光谐振腔研究的进展

本文对固体激光谐振腔的某些新进展,包括动态稳定腔、径向可变反射率镜腔和板条激光器用光腔,作了详细分析和讨论。     

Tunable Microwave Resonators Using Magnetostatic Wave in YIG Films

The purpose of this paper is to review the status of magnetostatic wave (MSW) resonators and to describe, in detail. the theory of operation of the recently developed straight-edge resonators. These resonators are based on magnetostatic waves propagating in high Q cavities fabricated in thin ferrimagnetic films. The resonance frequency of these resonators can be tuned via a bias magnetic field. The theory of propagation of magnetostatic wave devices in periodic arrays will be briefly described followed by a detailed overview of the different configurations for MSW resonators. Three distinct classes of resonators will be discussed 1) resonators based on array reflectors (deposited metals and etched grooves) will be described in detail; 2) guided-wave ring resonators will be discussed; and 3) the theory of operation and design criteria for the straight-edge resonators will be described. Each class will be evaluated, pointing out the advantages and drawbacks, and whenever applicable, the power handling properties and the phase noise performance will be given.     

Dual- and Triple-Mode Branch-Line Ring Resonators and Harmonic Suppressed Half-Ring Resonators

Ring resonators have been widely used for various applications. Dual-mode ring resonators have also been investigated due to their applicability to multifrequency mode requirement. In this paper, dual-mode ring resonators using a branch line are designed along with a systematic approach. Triple-mode branch-line ring resonators are also designed adding two branch lines to the ring resonator. Adding more branch lines, multimode resonators can be realized based on the design procedure developed here. The location of the branch lines determines the additional resonant frequencies other than the fundamental resonant frequency generated by the enclosing ring. Furthermore, half-ring resonators working at 2.5 GHz are proposed for suppressing multiple harmonics (second and third harmonics) and providing size reduction with employment of various physical configurations. Equalizing the even- and odd-mode phase delays, harmonics are suppressed effectively in the design of half-ring resonators. Double half-ring resonators with a long opening gap are investigated to continuously decrease the resonant frequency. An open-loop structure provides flexible design and lowers the resonant frequency. Two dual-mode ring resonators and one triple-mode ring resonator are simulated and fabricated along with three different half-ring resonators     

Splitting axially heterogeneous modes in microwave gyromagnetic and gyroelectric resonators

Theory of calculating eigenmodes spectrum for gyrotropic resonators when using scalar potentials formalism is developed. Equations for calculating splitting of resonant frequencies of gyromagnetic and gyroelectric cylinder resonators in magnetic field are derived. Theoretical results are compared to the experimentally obtained figures for microwave gyromagnetic resonators made of barium hexaferrite. Example of a resonator made of indium antimonide demonstrates the possibility of using magnetized semiconductor resonators cooled to liquid nitrogen temperature to achieve the same characteristics offered by resonators made of magnetically firm hexaferrites when designing unidirectional microwave devices.     

Design of resonators from sections of irregular transmission lines

The problem of minimization of the difference in the characteristic impedances of resonators designed from sections of smoothly irregular and stepwise irregular transmission lines, which have distributions of initial eigenfrequencies important for practice, is solved. This problem is solved using the parametric synthesis method in which resonator eigenfrequencies are used as independent variables. It is shown that stepwise irregular resonators have lesser differences in the characteristic impedances than smoothly irregular resonators. A characteristic feature of synthesized resonators, their tendency to most simple shapes, is found. A set of synthesized stepwise irregular resonators is presented and their main characteristics are described. Using features of the obtained solutions, a simple method for the design of stepwise irregular resonators with minimum difference in the characteristic impedances is proposed, which allows one to expand in future the set of resonators suitable for practical applications.     

Natural oscillations of radially three-layered dielectric resonators

Natural oscillations of radially three-layered dielectric resonators have been investigated. The latter have the form of a sphere and cylinder limited by ideally conducting end planes. The expressions for components of electromagnetic fields of natural oscillations and characteristic equations of resonators were obtained. Numerical investigations of resonators were carried out in the 8-millimeter wavelength band. The impact of the middle layer parameters of resonators on their spectral and power characteristics was also analyzed. It was proposed to use such resonators for extracting the complex dielectric permittivity of substances.     

同轴气体激光器二球面镜腔内光束的传输特性

本文以多程(臂)环形腔近似替代的方法分析同轴气体激光器二球面镜腔内光束的传输特性,得到一些有用的结果。     

Compact microstrip resonators for 900 MHz frequency band

A technique to reduce the size of planar resonators is investigated using a transmission line model and a finite-difference time-domain (FDTD) method. New miniaturized square microstrip resonators are proposed for 900 MHz band. The resonators offer low impedance sections leading to a better handling of power. The feasibility of compact filters using the proposed resonators is demonstrated. The input/output coupling lines of a two-pole filter have been positioned in a way that produces a filter response with transmission zeros on the both sides of the pass-band. Sharper skirts and higher out-of-band rejection are obtained for four-pole filters with cross-coupled resonators.     

Standing Wave Solutions of Planar Irregular Hexagonal and Wye Resonators

Suitable planar resonators for the design of three-port symmetrical junction circulators are the irregular hexagonal resonator and the wye resonator consisting of the junction of three open-circuited stubs. This paper describes the equipotential standing wave solutions and cutoff numbers of some lower order modes in such resonators using a finite element program. Circulator standing wave solutions in magnetized hexagonal and wye resonators are obtained by taking suitable combinations of those of the demagnetized resonators. The paper also includes the solution of planar resonators formed by the junction of four open-circuited stubs.     

压电陶瓷圆筒振子耦合振动的本征频率分析

研究了压电陶瓷圆筒振子的耦合振动,分析了振子的轴向、径向伸缩振动及扭转振动之间的耦合关系.从理论上推导出了振子耦合振动的共振频率方程.由于分析中对振子的几何尺寸未加任何限制.因此所得结论适用于任何尺寸的陶瓷圆筒振子,其中包括厚壁圆筒及圆环.理论分析表明.本研究计算简单,物理意义明显,与一维理论的结果相比,文中得出的振子耦合振动的共振频率与实测值符合较好.     

Design of unstable laser resonators with user-defined mode shape

By introducing surface-structured mirrors into stable laser resonators, the generation of user-defined mode profiles and properties has become possible. On a wave-optical basis, we show that there is a general connection between the property of the modes to be phase-conjugated during reflection at the mirrors and their diffraction losses at apertures. This connection makes the design method known for stable resonators with predefined modes unsuitable for the design of such resonators of unstable geometry. An alternative method for the calculation of unstable resonators with user-defined output beam shape is presented and demonstrated by an example design     

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     

腔光力系统中声子的朗道-芝诺-斯塔博格干涉（特邀）

微纳机械振子被认为是一种发展片上信号处理器件的理想平台,可以将各种不同的物理场转换为振动声子,实现基于声子的片上信息处理。其中,控制声子在不同机械振子间的传输是实现声子信息处理的关键。通过将两个机械振子耦合构造两模机械系统,目前虽然已经实现了不同杂化模式间声子的相干传输,但是依然缺乏直接调控两个独立机械振子有效耦合强度的方法。为此,文中在腔光力系统中开发了基于朗道-芝诺-斯塔博格（Landau-Zenner-Stückelberg,LZS）干涉的相干声子操控方法。在利用光学囚禁作用调控两个机械振子振动模式杂化的基础上,通过对囚禁光进行调制施加参量驱动场,使得系统周期性地穿过免交叉点实现了声子的LZS干涉。研究表明:在满足共振条件下,利用LZS干涉可以实现声子在两个独立机械振子间的相干传递。笔者的研究为实现声子信息在实空间的高效传递提供了一个有效途径。     

NEMS谐振器的研究与分析

介绍了NEMS谐振器的主要特点与性能参数。并且详细讨论了NEMS谐振器的材料、制备工艺以及激励与检测手段。同时根据结构与工作模态,分类介绍了近年来国际上出现的几种典型的NEMS谐振器。最后分析了NEMS谐振器发展所面临的挑战,并指出NEMS谐振器将具有良好的应用与发展前景。     

Nonradiating edges and four edges gap-coupled multiple resonator broad-band microstrip antennas

Two novel configurations for increasing the impedance bandwidth of the microstrip patch antennas are described. One of these configurations uses two additional resonators which are gap-coupled to the nonradiating edges of a rectangular patch, whereas in the second case, four additional resonators are gap-coupled to the four edges of a rectangular patch. Green's function approach and segmentation method are used for analysis. The experimental results are in reasonable agreement with analysis and impedance bandwidths of 480 MHz and 815 MHz are obtained for the three resonators and five resonators configurations, respectively (inS-band with substrateepsilon_{r} = 2.55and thickness = 0.318 cm).     

Circuit Properties of Microwave Dielectric Resonators

The purpose of this paper is to present experimental data on the circuit properties of dielectric resonators which do not have conducting boundaries. The resonators are constructed of single-crystal rutile and strontium titanate, which, as has been shown by several authors, can form resonators of miniatnre size and high unloaded Q. We consider the lowest-order H mode, give measured values of resonant freqnency (for rectangular parallelepipeds), mechanical frequency tuning, control of coupling to microwave circuits, and discuss the measurement of, and typical values of, external Q of resonators mounted in waveguides. We also consider periodic propagating circuits consisting of linear arrays of mutually coupled resonators.     

Gold-Plated Micromachined Millimeter-Wave Resonators Based on Rectangular Coaxial Transmission Lines

Resonators based on microfabricated rectangular coaxial (recta-coax) transmission lines are presented. The resonators were fabricated using a multilayered nickel electroplating process that enables the fabrication of three-dimensional structures. As a method to improve performance, gold was plated on the resonators using an electroless process. A model for predicting the effect of the plating on a resonator quality (Q) factor is presented and verified by measurements. Measured resonators show that the plating can increase the Q factor of nickel resonators by over 50% at frequencies above 44 GHz. Utilizing gold plating, 50-Omega resonators are demonstrated at 44 and 60 GHz with unloaded Q factors of 213.1 and 242.3, respectively     

GHz频带声表面波谐振器的研究

本文叙述了GHz频带声表面波谐振器的设计、制造和试验结果.对两种不同模式的声表面波谐振器进行了研究,它们是瑞利波型谐振器和表面横波型谐振器.对两种波型谐振器的频率温度特性进行了比较.最后对表面横波(STW)谐振器在振荡器中的应用进行了研究.