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Accurate determination of the complex permittivity of materials with transmission reflection measurements in partially filled rectangular waveguides

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2003年第1期51卷 16-24页

作者： Catalá-Civera, JM Canós, AJ Peñaranda-Foix, FL Davó, ED Univ Politecn Valencia Dept Comunicac Valencia 46071 Spain

An enhanced transmission reflection technique for the precise determination of the complex permittivity of dielectric materials partially filling the cross section of a rectangular waveguide is described. Dielectric properties are determined by an iterative procedure from two-port S-parameter measurements and a numerically generated propagation constant obtained from the analysis of a partially filled waveguide. Convergence of the solution is ensured from perturbational approximations. Unlike previous approaches, uncertainty investigation is performed, taking into account all the parameters involved in the dielectric characterization. Permittivity accuracy values are presented and, hence, an optimum measurement setup can be established. Measurements of reference materials have been carried out to validate the method.

关键词： accuracy study dielectric properties microwave measurements rectangular waveguides

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Full wave modeling of conducting posts in rectangular waveguides and its applications to slot coupled combline filters

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1995年第12期43卷 2824-2830页

作者： Yao, HW Zaki, KA Atia, AE Hershtig, R CTA INC ROCKVILLEMD 20852 K&L MICROWAVE INC SALISBURYMD

A full wave model of conducting posts in rectangular waveguides yielding their generalized S-matrix is presented. By cascading the generalized scattering matrices of the posts and waveguide discontinuities, slot couplings between two combline resonators are obtained. The validation and accuracy of the method are confirmed by comparing the numerical results with measured data, It is shown that both electric and magnetic couplings can be obtained by changing the slot positions, and the electric coupling is more sensitive to the tuning screw than magnetic coupling. A 6-pole slot coupled combline filter,vith asymmetrical transmission zeros is designed and built. Excellent filter responses are obtained.

关键词： rectangular waveguides Waveguide discontinuities Resonator filters Tellurium Scattering Transmission line matrix methods Couplings Convergence of numerical methods Termination of employment Resonant frequency

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Left-handed transmission characteristics of rectangular waveguides periodically loaded with ferrite

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IEEE TRANSACTIONS ON MAGNETICS 2005年第10期41卷 3532-3537页

作者： Ueda, T Tsutsumi, M Kyoto Inst Technol Dept Elect & Informat Sci Sakyo Ku Kyoto 6068585 Japan Fukui Univ Technol Dept Space Commun Engn Fukui 9108505 Japan

A left-handed rectangular waveguide periodically filled with tangentially magnetized ferrite medium has been proposed, and backward wave characteristics in the structure have been confirmed numerically by using a mode-matching method. The operational frequency is selected to be below the cutoff frequency for a dominant TE10 mode in a rectangular waveguide where the effective permittivity is negative. The obtained results show that there exist backward-wave modes in the negative permeability frequency region where magnetostatic surface wave modes can be supported, and the field profiles have a sinusoid-like form composed of a series of exponentials in each section. In addition, three-dimensional full-wave simulation is demonstrated, which shows that unexpected excitations of magnetostatic surface wave mode transversely propagating along a surface of the ferrite layer near the input port plays a role of a transformer from a guided TE10 mode to the backward wave mode and vice versa near the output port.

关键词： ferrite-loaded-waveguides left-handed transmission lines periodic structures rectangular waveguides waveguide theory

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THB-filled monolithic rectangular waveguides for millimeter wave applications

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IET MICROWAVES ANTENNAS & PROPAGATION 2014年第6期8卷 377-385页

作者： Vahabisani, Nahid Daneshmand, Mojgan Univ Alberta ECE Dept Edmonton AB Canada

A monolithic wafer-level dielectric-filled rectangular waveguide for millimeter-wave applications is designed and fabricated. Unlike the existing wafer-level rectangular waveguides that are based on hybrid integration techniques to assemble the waveguide, the three-step fabrication process of the proposed waveguide enables the simultaneous monolithic fabrication of the dielectric-filled waveguide as well as planar circuitry on one substrate. The maximum temperature during the entire fabrication process stays lower than 200 degrees C which is desirable for integrated circuit (IC) fabrication. Besides, the RF performance of the presented waveguide only depends on the RF properties of the filling dielectric not the carrier substrate (as in the case of Substrate Integrated waveguides), which makes it ideal for silicon micro-fabrication technology. A negative-tone thick photoresist called THB N151 which can reach a thickness of 90 mu m by single spinning is used and characterised. The results show a relative permittivity of e(r)' = 3 and a loss tangent of tan delta = 0.018 for THB 151 which surpasses the RF performance of the highly used SU8 photoresist. An average insertion loss of 0.21 dB/mm is measured for the THB-filled waveguide for the frequency range of 35-50 GHz. To perform the wafer-level measurements, the waveguide is integrated with CPW to rectangular transition. Furthermore, it has been illustrated that other monolithic waveguide structures such as Turn or Y-junction can be potentially developed by using the proposed solution.

关键词： millimeter wave substrate integrated waveguides rectangular waveguides frequency ranges Waveguide Device Component Y junction coplanar waveguides radiofrequency insertion loss MONOLITHIC LOSS TANGENT Fabrication process Dielectric constant Integrated circuits

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A Mode-Matching-Based Formulation for the Analysis of Curved rectangular waveguides

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2023年第9期71卷 3810-3818页

作者： Rosa, Guilherme S. Pontifical Catholic Univ Rio De Janeiro Ctr Telecommun Studies Dept Elect Engn BR-22451900 Rio De Janeiro Brazil

This article presents a mode-matching formulation for the scattering analysis of curved rectangular waveguides. We use exponentially scaled Hankel functions with complex-valued orders to solve the electromagnetic fields in E-and H-plane bend configurations, and then, we obtain a generalized scattering matrix (GSM) representation for characterizing U-and S-shaped waveguides. Numerical results show that our method is accurate and computationally efficient compared with a finite-element method (FEM) and experimental reference solutions.

关键词： Electromagnetic waveguides rectangular waveguides GSM Waveguide junctions Transmission line matrix methods Waveguide components Geometry Bent waveguide curved rectangular waveguide mode-matching method scaled cylindrical functions

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Numerical and experimental studies of split ring resonators loaded on the sidewalls of rectangular waveguides

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IET MICROWAVES ANTENNAS & PROPAGATION 2009年第8期3卷 1262-1270页

作者： Quevedo-Teruel, O. Rajo-Iglesias, E. Kehn, M. Ng Mou Univ Carlos III Madrid Dept Signal Theory & Commun Leganes 28911 Spain Chalmers Dept Signals & Syst S-41296 Gothenburg Sweden Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada

This work investigates the use of a lattice comprising split ring resonators (SRRs) as a negative permeability medium to achieve backward travelling modes within a rectangular waveguide. The loadings of such SRR-type periodic structures into a waveguide can be tailored such that the backward mode exists in a passband below the ordinary basic modal cutoff frequency, thus affording filtering capabilities and miniaturisation. Theoretical studies by two approaches are performed here, a moment method spectral domain analysis, and a commercial simulation tool. Parametric studies that characterise the effects of various dimensional and electrical properties on the dispersion behaviour of the SRR-loaded waveguide shall also be conducted. The SRR parameters are then optimised using the ant colony optimisation (ACO) algorithm to achieve a low backward passband, for a high degree of miniaturisation and isolation. Experimental results of measurements performed on a manufactured prototype of the optimised SRR-loaded waveguide will also be presented.

关键词： waveguides and microwave transmission lines Optimisation techniques Waveguide and microwave transmission line components split ring resonator rectangular waveguide Other numerical methods microstrip rat race resonator periodic structures optimisation permeability rectangular waveguides spectral domain analysis microstrip resonators negative permeability medium spectral analysis method of moments backward travelling mode periodic structure ant colony optimisation algorithm moment method

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Efficient analysis of a cubic junction of rectangular waveguides using the admittance-matrix representation

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IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION 2000年第6期147卷 417-422页

作者： Boria, VE Cogollos, S Esteban, H Guglielmi, M Gimeno, B Univ Politecn Valencia Dept Comunicac Valencia 46022 Spain European Space Agcy European Space Res & Technol Ctr NL-2200 AG Noordwijk Netherlands Univ Valencia ICMUV Dept Fis Aplicada E-46100 Burjassot Valencia Spain

In the paper an efficient and accurate method, based on the multimode-admittance-matrix representation and the theory of cavities, is proposed for the analysis of a six-port 'cubic' junction composed of the orthogonal intersection of three rectangular waveguides. Very simple closed-form analytical expressions are explicitly detailed for all matrix elements of this basic key building block. More general waveguide multiport junctions, composed of a central cubic junction with arbitrarily shaped waveguide access ports, are also studied using a segmentation procedure. To validate the theory, numerical results are first discussed for a standard rectangular waveguide six-port cross junction. Finally, the analysis method proposed is also successfully applied to H- and E-plane T-junctions whose side arms are waveguides with rounded corners.

关键词： H-plane T-junctions waveguide theory waveguide multiport junctions cavity theory segmentation procedure six-port cross junction central cubic junction multimode-admittance-matrix representation Waveguide and cavity theory rectangular waveguides cubic junction matrix algebra shaped waveguide access ports numerical results E-plane T-junctions Waveguide and microwave transmission line components waveguides and microwave transmission lines closed-form analytical expressions electric admittance waveguide junctions six-port junction

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SCATTERING MATRIX OF JUNCTIONS BETWEEN rectangular waveguides

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IEE PROCEEDINGS-H MICROWAVES ANTENNAS AND PROPAGATION 1983年第2期130卷 183-190页

作者： DESMEDT, R DENTURCK, B Laboratorium voor Elektromagnetisme en Acustica Rijksuniversiteit te Gent Gent Belgium

The scattering matrices of junctions between rectangular waveguides are investigated for waveguides either below or above cutoff. The convergence properties of the ‘moment-’ and ‘point-matching’ numerical methods are compared. A ‘perturbation’ algorithm is developed for the case when, in the double junction, the distance between planes is large. Data for the design of single and double junctions are provided, and checked experimentally.

关键词： waveguides and microwave transmission lines convergence scattering matrices junctions Electromagnetic wave propagation electromagnetic wave scattering waveguides perturbation scattering matrix rectangular waveguides

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Synthesis of configuration of uniformly radiating longitudinal slots in the sections of nonregular rectangular waveguides

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 1998年第2期46卷 188-191页

作者： Davidovich, MV Meschanov, VP Cent Res Inst Measuring Equipment Saratov 410002 Russia

The integral-equation method has been applied along with perturbation theory to investigate the leaky-wave parameters of the fundamental mode in the regular waveguide with a narrow longitudinal slot on its broad wall, opened into shielded semispace, Then, the simple analytical formulas have been derived for the engineering synthesis of radiating elements (RE's), which are formed by a nonuniform waveguide section with a nonregular slot on its broad Hall, The long slot was cut in the longitudinal direction along certain curved or several connected broken lines, forming small local angles with the waveguide axis, The synthesis of RE's by single-mode approximation has been carried out for the condition of good uniformity of radiating electrical-field distribution along the RE axis near the slot. Good agreement of theoretical and experimental results were obtained.

关键词： rectangular waveguides Waveguide theory Resonance Phased arrays Power distribution Electromagnetic heating Waveguide components Dielectric measurements Electrodynamics

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Single-Layer Evanescent Wave Absorbers in rectangular waveguides Based on Evanescent Mode Coupling and Attenuation

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2023年第5期71卷 4394-4405页

作者： Yi, Da Zhao, Pei-Rong Tang, Ming-Chun Zhang, Ren-Long Wei, Xing-Chang Li, Er-Ping Chongqing Univ Coll Microelect & Commun Engn Key Lab Dependable Serv Comp Cyber Phys Soc Zhejiang Prov Key Lab Adv Microelect Intelligent S Chongqing 400044 Peoples R China Chongqing Univ Chongqing Key Lab Space Informat Network & Intelli Chongqing 400044 Peoples R China Zhejiang Univ Coll Informat Sci & Elect Engn Hangzhou 310027 Peoples R China

A microwave absorber for absorbing waves below the cutoff frequency of a rectangular waveguide (RWG) is proposed in this study. By loading an ideal lossy capacitive metasurface (LCMS) in the cross Section of an RWG close to the radiation source, the LCMS exhibits the ability to couple with and attenuate the waves below the cutoff frequency of the RWG, that is, absorb the evanescent waves (EWs). The operating mechanism is analyzed with several parametric studies based on the momentum-matching principle, and a systematic design procedure for a practical EW absorber is concluded. Three samples made of indium tin oxide (ITO) thin films are designed, fabricated, and tested, and the experimental results agree well with the theoretical results. The maximum measured absorptance reaches up to 97%. Compared with conventional plane-wave absorbers with multilayer conductors, the proposed EW absorber only requires a single-layer conductor and has a distinct working mechanism, design principle, and application scenario. In the examples considered in this study, the samples can serve as the specific matching component for calibrating the RWG below the cutoff frequency. Notably, our EW absorption technique provides a feasible approach to suppress the electromagnetic interference (EMI) dominated by the evanescent mode in the electrically small metallic cavity packages and near field (NF) of integrated circuits (ICs).

关键词： Probes Cutoff frequency Noise measurement Absorption Conductors Electromagnetic interference rectangular waveguides Electromagnetic interference (EMI) evanescent wave (EW) metasurface microwave absorber rectangular waveguide (RWG)

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