Resonant Properties of Nonreciprocal Ring Circuits

The ring circuit investigated consists of a resonant ring guide coupled to a main guide. The properties can be described by the equations for the waves in the ring guide resulting from excitation in the main guide. The influence of nonreciprocity on the properties is investigated under conditions of varying coupling. The representation of the ring waves by the poles and zeros is chosen to permit interpretation of the results under the large variety of operational conditions with respect to coupling and nonreciprocity. The application for measuring the material constants of ferrites is discussed.     

Short End Effect of Ridge Guide with Planar Circuit Mounted in a Waveguide

The end effect of the short end ridge guide with planar circuit mounted in a waveguide is theoretically obtained by a variational method. The results were also confirmed by measured values. The resonant frequency of a ridge guide resonator was also obtained by using the above mentioned end effect.     

基于HMSIW的宽带带通滤波器设计

为有效减小C波段基片集成波导的尺寸和插入损耗,提出了一种基于半模基片集成波导的紧凑型宽带带通滤波器。该滤波器引入由单个谐振槽和多个谐振槽组成的缺陷微带结构,并对其性能进行了研究。通过HFSS仿真验证,引入的缺陷微带结构,不仅可以减小插入损耗,而且实现传输零点的引入,改善了阻带特性。该方法设计的半模基片集成波导带通滤波器具有集成度高、体积小、成本低、制造方便等优点,在C波段卫星和雷达中得到了广泛的应用。     

Stepped Transformers for Partially-Filled Transmission Lines (Comments)

The use of a lumped equivalent circuit for the transverse section of a waveguide has been used to determine the cutoff frequency of ridged guide. In essence, the transverse section of the guide is equated to an LC tank and the resonant frequency of the tank is determined by the usual formula. Sullivan and Parkes have extended this method to the analysis of a ridged guide partially loaded with dielectric. They account for the additional capacitance introduced by the dielectric and include this capacitance as part of the LC tank to be analyzed for the resonant frequency. While the simplified lumped-network equivalents are always desirable in analyzing microwave networks, we should be wary of overgeneralizing them. In the case of dielectric slab loading in a waveguide, the location of the added capacitance as well as its maguitude has an effect in determining the cutoff frequency. (This can also be said of the discontinuity capacitance at the edge of a ridge.) Note how a dielectric slab when centered in a rectangular waveguide will lower the cutoff frequency far more than when flush with the sidewall. This is not accounted for in the LC tank equivalent. The effect of each increment of capacitance due to each lamina of dielectric will be largely determined by the distance from the lamina to the short-circuit walls. Therefore, the author believes that the case of a partially dielectric-loaded guide can only be genuinely analyzed by the transverse resonance method or by some other method which accounts for the distributed parameters involved.     

Magneto-inductive waveguide

A new magnetic waveguide is described, the operation of which is based on inductive coupling between resonant elements. The general form of the dispersion equation is shown. For a particular embodiment of the waveguide, consisting of 26 elements, the relative values of the currents are plotted and the travel of power from the first to the last element is shown by the streamlines of the Poynting vector. Application, as a magnetic guide for magnetic resonance imaging (MRI) is proposed     

利用偏移半销钉结构设计带阻滤波器

介绍了一种新颖的波导类椭圆带阻滤波器.该滤波器的结构由传输TE10主模的矩形波导中的偏移半销钉和四分之一波长传输线组成.波导中半销钉的等效电路即在谐振频率处为一个串联LC谐振电路,此谐振电路产生一个衰减极点.销钉的高度主要用来控制谐振频率,销钉距离波导中心的偏移量用来控制谐振单元间的耦合强度.最后设计了一个中心频率为9...     

Perturbation analysis and modeling of curved microstrip bends

The curved microstrip bend consisting of a microstrip ring segment between two microstrip lines is analyzed for its transmission properties. The microstrip lines are modeled by equivalent ideal magnetic wall waveguides for which the electromagnetic field solutions are known. The field solutions in the microstrip ring segment are derived by using a perturbation analysis of a modified (magnetic wall) curved waveguide model. Other techniques have been formulated to evaluate the fields inside curved metallic waveguides. These include the use of an equivalent nonuniformly loaded straight waveguide and rectangular and annular model analysis. The perturbation solution for the fields in the equivalent curved waveguide model presented is readily adaptable to the mode-matching procedure, and is used to calculate the properties of the curved microstrip bend discontinuities. The frequency-dependent reflection and transmission coefficients of curved microstrip bends are determined and compared with those of the right-angle and chamfered right-angle microstrip bends     

Monolithic millimetre-wave oscillator using a transmission lineperiodically loaded by QWITT diodes

A small-signal analysis of a travelling-wave structure implemented by periodically loading a parallel-plate waveguide with either resonant tunnelling or QWITT diodes is presented. A small-signal equivalent circuits is used to determine the diode impedance as a function of frequency. The periodicity of the structure, i.e. the distance between adjacent diodes, determines the oscillation (resonant) frequency of the circuit. The analysis shows that change in the oscillation frequency through variation in the design width and thickness of the waveguide is minimal. The physical dimensions of the waveguide facilitate monolithic fabrication of the oscillator circuit     

A new type of waveguide ring cavity for resonator and filterapplications

A new type of rectangular waveguide ring cavity has been developed for applications to resonators, filters, and multiplexers. The circuits have advantages of high Q and high power handling capability. H-plane and E-plane waveguide ring cavities have been investigated thoroughly in single-mode and dual-mode operations. For single-mode operation, regular resonant modes, split resonant modes, and forced resonant modes were explained by resonant mode charts of E-field points. Mechanically tuned and electronically tuned resonators built by adjusting the resonant modes between regular resonant modes and forced resonant modes have been demonstrated. For dual-mode operation, a dual-mode filter using a single H-plane ring cavity has been built with a bandwidth of 0.77%, a stopband attenuation of more than 40 dB, and a sharp gain slope transition. Another dual-mode filter which was formed by cascading two E-plane ring cavities has also been fabricated with a bandwidth of 1.12%, a stopband attenuation of 70 dB, a mode purity of 2 GHz at the center frequency of 26.82 GHz, and a sharp gain slope transition     

Millimeter-Wave (W-Band) Quartz Image Guide Gunn Oscillator

Dielectric image-guide Gunn oscillator using fused quartz as the guide material has been investigated at frequencies around 94 GHz. Computer-controlled CO/sub 2/ laser cutting of quartz to the designed image-guide patterns has also been achieved. A resonant disk and pin bias circuit was used to tune the oscillator to an output power of 5 mW at the oscillation frequency of 94.2 GHz. An electronic frequency tuning of 350 MHz was measured with the oscillation characteristics similar to waveguide cavity oscillators. By varying the bias circuit disk and pin parameters, the Gunn-oscillator tuning characteristics have also been recorded for the future circuit performance optimization.     

复合缝波导耦合器的全波分析

本文使用时域有限差分法 (FDTD法 )对由两根正交矩形波导构成的复合缝耦合器进行了严格分析 ,得出在不同偏置、倾斜角度和谐振频率下耦合缝隙的谐振长度和散射参量特性 ;并对带有短路器的复合缝波导耦合器系统进行了分析 ,得出短路片移动时该小系统的传输特性     

Coplanar waveguide excitation of dielectric resonator antennas

The circuit and radiation properties of a cylindrical dielectric resonator antenna excited by a coplanar waveguide feed are investigated. The coupling between the feed and the radiator was measured as a function of the position, dielectric constant, and height of the cylinder. The radiation patterns and resonant frequencies were also measured. These measured results are found to be in good agreement with theoretical calculations     

On the interaction of the MMIC and its packaging

The software package WATMIC-EMsim is used to simulate the interaction of an MMIC circuit and its packaging. The circuit used is the spiral transformer, and the packaging is the surrounding ground ring used to interface the transformer to its coplanar probes. It is found that the resonant frequencies of the transformer are affected greatly with the introduction of the ring but, with its introduction, only slightly by the width of the ring. It is pointed out that this interaction mimics a well-known phenomenon in electrostatic capacitance. The results show that in the field-theoretic analysis of an MIC/MMIC circuit the influence of the packaging must be considered     

波导阻抗带宽与缝隙导纳关系研究

本文从谐振阵等效网络出发,探索了缝隙波导谐振阵实现理想阻抗匹配的导纳特性,为波导谐振阵的超宽带设计提供了新思路.改进了波导并联缝隙的等效电路,首次实现缝隙导纳特性的单参数表征,创新提出了不同单元间距与单元数缝隙波导阵实现最大带宽的导纳特性分析方法,为波导缝隙阵带宽的优化设计提供了理论依据,建立了传统谐振阵非过载时的最大...     

Tunable, Dielectric-Loaded Microwave Cavities Capable of High Q and High Filling Factor

Many applications require the presence of a dielectric inside a microwave resonator. This paper presents a new type of dielectric-loaded cavity and contains a detailed analysis of its properties. The cavity consists of a waveguide of arbitrary but uniform cross section, filled with dielectric for part of its length, with movable shorting plungers in the guide beyond one or both ends of the dielectric. Such a structure supports resonances at frequencies where a particular waveguide mode is above cutoff in the dielectric, but below cutoff outside. These resonances can have high Q's, especially when the cavity ends are open. Frequency tuning is possible via the movable plungers. The present analysis investigates resonant frequency, tuning range, and electric and magnetic filling factors. Wall losses are calculated for the particular case of a circular cross section. All results are plotted as universal design curves. The results indicate that this configuration is quite versatile and should be useful in numerous applications, including microwave solid-state masers, microwave light modulators, and the study of "ghost mode" resonances in waveguide windows.     

波导缝隙谐振阵带宽与缝隙特性关系研究

该文结合波导缝隙天线等效电路和辐射缝隙导纳特性,分析了并联辐射缝特性对波导谐振阵方向图带宽的影响,推导出天线方向图理想带宽所需要的缝隙特性.该结果为展宽谐振阵带宽提供了一种思路,为宽带波导谐振阵的设计提供有益参考.     

Waveguide/resonant-disc circuits for millimetre-wave devices

Bias circuits using resonant discs have been employed for millimetre-wave transferred-electron (TE) diodes operating at their second or third harmonic frequencies in the V (50?75 GHz) and W (75?110 GHz) bands. It is shown that this type of circuit exhibits resonances at frequencies in the lower millimetre-wave range, corresponding to the fundamental oscillation frequency of diodes typically used. In addition, the circuit provides efficient coupling to the waveguide circuit at the higher (harmonic) operating frequency. By tuning the fundamental oscillation frequency of a number of resonant discs, the power-frequency spectrum of the TE device can be determined, which is demonstrated for a device with its maximum third-harmonic power output at 94 GHz.     

Multimode deposited silica waveguide and its application to an optical branching circuit

A fabrication procedure has been developed for multimode deposited silica waveguide (DS guide), consisting of uniform and thick glass layer formation for core and cladding, and amorphous Si mask film for reactive sputter etching. The embedded multimode DS guide with a square core cross section has a transmission loss of 1.3 dB/cm at 633 nm wavelength. Waveguide parameters, such as core dimension, refractive index, and index difference, are similar to those of a multi-mode silica fiber. A multimode optical branching circuit with eight output ports was demonstrated by the above fabrication procedure. Excess insertion loss was 2 dB.     

Tunable Y-type waveguide power divider as standard mismatch

A method is proposed for generating standards of voltage standing wave ratio (v.s.w.r.) of values ? 2 by a waveguide device consisting of a Y-type junction matched to the input guide (power divider), with a tunable ratio of power division, an adjustable sliding short circuit and a matched load. A detailed analysis of errors is given, which considers the effects of a possible deviation of the symmetry of the junction and of the uncertainties in the determination of the reflection coefficient and of the position of the short circuit.     

Mode Chart for Microstrip Ring Resonators (Short Papers)

A universal mode chart for the microstrip ring resonator, based on a radial waveguide model, is presented. The resonant frequency is related to the width of the ring conductor. Experimental results from 4 to 16 GHz are shown to be in good agreement with the theory.