新型电单负材料结构在天线互耦抑制中的应用

单负材料所具有的电磁禁带特性可应用于阵列天线中降低天线单元间的互耦.文中研究设计了一种电单负材料结构单元ENG-APSL, 采用等效电路和波导传输法分析了ENG-APSL的电磁特性, 并提取等效参数.然后, 将基于ENG-APSL单元构成的隔离器用于抑制微带阵列单元间的互耦.研究表明, 天线阵列单元间距为0.37λ₀(λ₀为天线工作频率波长)条件下, 加载隔离器后天线阵列单元的E面耦合度降低了21 dB, 并且在工作频率(5.1 GHz)附近隔离度大于25 dB的带宽达到5.1%.同时, 该隔离器具有结构简单、尺寸小的突出优势.     

S-resonator with an end reflector

An S-resonator with an end reflector (SRER) is analyzed in terms of its resonance conditions and directional properties. An S-resonator has a main fiber ring to which is attached an S-shaped fiber by means of two couplers. Compared to the basic S resonator (BSR), the SRER has a highly reflecting reflector at a free end of one of the coupler ports. Because of the complex recirculating routes in the two resonators, their characteristics depend strongly on the coupling coefficients of the couplers; the phase resonance condition for the subcavity can even be shifted from an even to an odd integer of π, or vice versa. The new resonator can offer a higher clockwise over counterclockwise circulating intensity ratio. This can be very useful in the design of a ring fiber laser without an isolator     

A novel coupling structure suitable for cross-coupled filters with folded quarter-wave resonators

A new class of coupling structure for cross-coupled filters with folded quarter-wave resonators is presented. The cross coupling mechanism is realized by magnetic coupling from the short ends of the resonator. The proposed magnetic coupling solves the problem of response limitation of folded quarter-wave resonator cross-coupled filters that were introduced previously using electrical cross coupling. Several quadruplet and trisection filters are proposed and fabricated. The measured results matched well with the theoretical prediction.     

The Influence of a Coupling Film on Ultra-Low-Loss Dielectric Measurement Using an Open Resonator

A Fabry-Perot open resonator excited through a coupling film and loaded with a plane-parallel dielectric plate is analyzed. The eigen equation of the field in the resonator is obtained. The quality factors of the resonator with and without a coupling film are compared. The quality factors of the resonator loaded with a plate that is in resonance and off resonance are also compared. It is shown that the difference in coupling losses between a loaded resonator and an unloaded resonator may strongly affect the accuracy in measuring ultra-low loss dielectric material. Some ways to reduce the influence of coupling loss are discussed. Our experiment results are consistent with the numerical analysis.     

Modeling of cylindrical dielectric resonators in rectangularwaveguides and cavities

The mode matching method is used to accurately model a generalized cylindrical dielectric resonator structure in a rectangular waveguide or cavity. The field distributions of different modes in cavities are given. The resonant frequencies of the cavities are calculated and compared to the measured data, showing very good agreement. The resonator structure can be a dielectric disk resonator, a ring resonator, a dielectric resonator with support, etc. This structure can be used in filter design as the basic element, providing very good mechanical stability. The slot coupling between cavities is also analyzed, showing some interesting results     

基于SRR的超材料太赫兹调制器结构设计与调制深度仿真

电磁超材料可用于构建具有控制太赫兹辐射通断功能的太赫兹强度调制器.利用COMSOL仿真软件,通过模拟仿真,研究了基于开口谐振环(SRR)“工字型”超材料太赫兹调制器关键功能结构对器件透射光谱的影响规律,并以此完成了高调制深度器件的结构优化设计.仿真结果表明:优化后器件调制深度达到了74％.     

X波段SIW广义切比雪夫超结构滤波器设计

基于基片集成波导设计了一种正交分裂环谐振器,并证明了该谐振器具有双负特性。将该超结构放置于双层基片集成波导中,得到了具有频率选择特性的四端口耦合结构。将加载正交分裂环谐振器的耦合结构与广义切比雪夫滤波器相结合,设计了一种X波段SIW广义切比雪夫超结构滤波器。仿真结果表明,设计的滤波器满足了中心频率为10.519 GHz、相对带宽为0.25%、通带内的插入损耗小于-1 dB、回波损耗小于-20 dB的技术指标。     

The Oscillator Spectra Improving by a Compact System of Coupled Resonators

The results of the experimental research of a dipole-aperture line (DAL) formed by two coupled cylindrical slot lines are presented. It is shown that such structure can interact actively with the field of an open quasi-optical resonator. Conceptual possibility of technical realization effective coupling of an open resonator with the load by means of waveguide structures of DAL type having the quasi-dipole patterns of scattered fields is proved.     

LiNbO_3单晶薄膜体声波谐振器的研制

该文介绍了一种采用智能截割(Smart Cut~(TM))技术制备的单晶铌酸锂(LiNbO_3)薄膜体声波谐振器。采用COMSOL有限元仿真软件从材料和结构两方面对LiNbO_3薄膜体声波谐振器进行优化设计,以实现高机电耦合系数,并通过Smart Cut~(TM)工艺方法制备了高性能Z切-LiNbO_3单晶薄膜作为谐振器的压电层,最终得到LiNbO_3薄膜体声波谐振器的谐振频率为3 847.5 MHz,反谐振频率为3 986.25 MHz,插入损耗为1.81 dB,谐振器有效机电耦合系数达到8.3%。     

声能量收集器的研究综述

声能是环境中普遍存在的一种能量形式,如何收集并应用这一能量成为当下研究热点。介绍了亥姆霍兹谐振腔、声晶体谐振腔、四分之一波长谐振腔以及其他非腔体结构声能收集系统的结构及其优化方案。实验结果表明,与亥姆霍兹谐振腔相比,使用同等尺寸的声晶体谐振腔能获得更高的能量收集效率,而四分之一波长谐振腔能以更小的体积收集同样的声能。另外,结构优化和耦合设计可以极大地提升能量收集效率。许多非腔体结构的设计也有着不错的应用前景。     

Design and modeling of waveguide-coupled single-mode microringresonators

We discuss a first-order design tool for waveguide-coupled microring resonators based on an approximate solution of the wave propagation in a microring waveguide with micron-size radius of curvature and a large lateral index contrast. The model makes use of the conformal transformation method and a linear approximation of the refractive index profile, and takes into account the effect of waveguide thickness, dispersion, and diffraction. Based on this model, we develop general design rules for the major physical characteristics of a waveguide-coupled microring resonator, including the resonance wavelength, the free spectral range, the coupling ratio, the bending radiation loss and the substrate leakage loss. In addition, the physical model provides leads to alternative coupling designs. We present two examples, one using a phase-matching parallel waveguide with a smaller width than the ring waveguide, and the other using a vertical coupling structure. Both these designs significantly increase the coupling length and reduce or eliminate the dependence on a narrow air gap in a waveguide coupled microring resonator     

Analysis of the properties of slow-wave structures based on coaxial resonators coupled by two arc-shaped waveguides

The dispersion and the coupling resistance of spatial harmonics of slow-wave structures formed by a chain of coaxial resonators coupled by arc-shaped waveguides are theoretically analyzed. A 3D vector boundary value problem is solved in the rigorous electromagnetic formulation with the use of projection methods. The 2D problems of excitation of a coaxial resonator are considered and amplitudes of excited waves are determined and used for solution of the 3D problem of the junction of arc-shaped waveguides and a coaxial resonator. The dispersion equation for the considered slow-wave structure is obtained. The results of calculation of the dispersion and the coupling resistance for different numbers and different configurations of coupling apertures are analyzed.     

太赫兹硅基微环谐振器的设计与分析

设计了一个工作频率在太赫兹大气传输第一窗口的硅基波导型微环谐振器。利用传输矩阵法和耦合模理论计算微环谐振器的传输函数,并对波导耦合系数进行分析,获得微环谐振器的临界耦合条件。采用时域有限差分法分析微环谐振器的性能参数,并与串联双环谐振器性能参数相比较。结果表明：单环谐振器的自由谱宽范围为27 GHz,插入损耗为0.3 dB。单环与双环谐振器的响应谱线形状因子分别为0.16和0.52,即串联双环谐振器使谐振谱线顶端更平坦,滚降度增高。Abstract：关键词：     

2.4‐GHz Power Amplifier with Power Detector Using Metamaterial‐Based Transformer‐Type On‐Chip Directional Coupler

This letter presents a power amplifier (PA) with an on‐chip power detector for 2.4‐GHz wireless local area network application. The power detector consists of a clamp circuit, a diode detector, and a coupled line directional coupler. A series inductor for an output matching network in the PA is combined with a through line of the coupler, which reduces the coupling level. Therefore, the coupler employs a metamaterial‐based transformer configuration to increase coupling. The amount of coupling is increased by 2.5 dB in the 1:1 symmetric transformer structure and by 4.5 dB from two metamaterial units along the coupled line.     

厘米波段介质带通滤波器的设计与制作

为了提高基站的通信质量,研制了高性能的窄带介质带通滤波器。选择切比雪夫低通原型设计线路,采用6个环形介质谐振器直接耦合实现滤波器,输入输出采用探针耦合。用HFSS软件对滤波器的结构进行了仿真。用εr=38的高Q值介质陶瓷材料制作了环形谐振器,分析了衬垫材料的高度对环形谐振器性能的影响,测试了级间耦合系数。最后制作出中心频率为6GHz的介质带通滤波器,滤波器的带宽窄（0.5%）,插入损耗较小,阻带衰减很高,达到了国内先进水平。     

Compact dual-mode elliptic-function bandpass filter using a singlering resonator with one coupling gap

A novel microwave dual-mode elliptic-function bandpass filter with one coupling gap structure is proposed. This filter has a 4.7% bandwidth at 1.805 GHz with 1.73 dB insertion loss. The filter provides less field perturbation of the ring resonator than conventional filters. Without the output coupling gap between the feed line and the ring resonator, a low insertion loss has been obtained. This compact, high performance filter is useful for mobile and personal communication systems     

Cavity coupling structure for planar oscillators showing DR-likereflective characteristics

A new cavity coupling structure has been developed for low-phase noise oscillator applications. Unlike the conventional cavity coupling structures that show absorption at the resonant frequency, the new structure shows high reflection at resonance similar to dielectric resonators, making it suitable for the reflective oscillators. The fabricated cavity resonator showed a loaded Q-factor of 1200 and the X-band oscillator using the new resonator showed phase noise proper-ties of -57 and -83 dBc/Hz at 1 and 10 kHz offset, respectively. This is comparable to the best results of dielectric resonator oscillators using HEMTs at this frequency range     

基于集总电阻的S波段小型化超材料吸波器

提出了一种基于集总电阻的S波段小型化超材料吸波器(Metamaterial Absorber,简称MMA)结构, 并进行了理论分析和仿真验证。设计的MMA 基本单元结构由加载了集总元件的电谐振器、中间隔离层和金属背板组成。利用S 参数反演算法求出等效阻抗,结果表明集总电阻的加入使该MMA 在较宽频带范围内有较好的阻抗匹配特性。根据等效电路理论,分析了MMA谐振吸收频率与其单元结构几何参数之间的关系。通过MMA 单元结构表面电流和能流分布分析了其吸波机制。不同模式下的极化角和斜入射角吸收率表明:该MMA具有极化不敏感和宽入射角特性。进一步研究MMA 结构-参数对其吸波性能的影响,通过单元结构几何参数和集总参数的调节获得最优的MMA模型。最终,通过MMA基本单元结构的进一步优化设计,使其在1.9～6.0GHz 范围内吸收率达到90%以上,对应的相对带宽达到101.9%。该设计有望在电磁能量捕获及隐身领域拥有潜在应用价值。     

Efficient analysis of microstrip-coupled nonradiative dielectric(NRD) resonators for hybrid integrated circuits

Nonradiative dielectric (NRD) resonators have been recently known as excellent stabilizing components for the design of a new class of oscillators based on hybrid integration of planar circuits and NRD-guides. However, an accurate characterization of such a component is needed in order to develop efficient computer-aided-design programs. In this paper, a hybrid planar integrated circuit comprising an NRD resonator is accurately modeled and is coupled to input and output planar microstrip circuits by means of long slots located on the top ground plane of the NRD structure. A reciprocity approach is used to solve the coupling problem between the resonator and microstrip lines. A modal expansion of the field equations has been applied to the NRD resonator in obtaining its rigorous field expressions. Finally, a transmission-line analysis is proposed for the structure, and scattering parameters have been calculated for different slot positions. Results are discussed for various parametric effects on coupling and Q-factor characteristics