Hybrid-mode Analysis Research Articles

A Unified Hybrid-Mode Analysis for Planar Transmission Lines with Multilayer Isotropic/Anisotropic Substrates

A unified hybrid-mode analysis is presented for determining the propagation characteristics of multiconductor, multilayer planar transmission lines. The analysis employs the conservation of complex power technique, and the emphasis is on numerical efficiency and simplicity. Numerical results, for finline and microstrip configurations, aim at the clarification of the effects of the metalization thickness, dielectric anisotropy, and substrate mounting grooves.

Technical memorandum: Hybrid-mode analysis of shielded and coupled slotlines on a suspended substrate

A hybrid mode analysis is presented for shielded single and coupled slotlines on a suspended substrate. The method is based on the transverse modal analysis (TMA) technique. Numerical results are consistent with other theories.

Technical memorandum: Transverse modal analysis of multilayer microstrip transmission lines

A hybrid mode analysis is presented for a multilayer dielectric within a rectangular conducting box. Specific results are obtained for a 3-layer structure and compared with those in the literature.

Technical memorandum: Quasistatic and hybrid-mode analysis of shielded coplanar waveguide with thick metal coating

A unified approach is presented to give the quasistatic and hybrid-mode solutions of the shielded coplanar waveguide (CPW) with a uniaxially anisotropic substrate. The quasistatic formulation is based on the variational method and the stationary expression of the line capacitance of the shielded CPW is derived for the first time. The present method takes the metallisation thickness into consideration and it presents accurate numerical values both for the quasistatic and frequency-dependent hybrid-mode solutions. The frequency-dependent characteristic impedances based on various definitions are investigated.

The Hybrid-Mode Analysis of Coupled Microstrip-Slot Resonators (Comments)

We were interested to read the above paper, but it calls for a remark concerning the extension of the hybrid-mode analysis to coupled microstrip-slot resonator. In fact, when the coupled strips are very close to each other, the basis functions used in the above paper does not allow one to obtain a satisfactory resonant frequency. To do so, we must necessary increase the number of basis function by using symmetric and antisymmetric basis functions with respect to the axis of a strip. In this case, we must be sure that the criterion of relative convergence is satisfied. Furthermore, the mathematical developments of this hybrid-mode analysis have been already published by the same author. So it would have been better to focus the purpose of the above paper on the problem more specific to the coupling of the two strips.

Accurate numerical analysis of an elliptically cored optical fiber for polarization preservation, using mode‐matching method

AbstractThe Mode‐Matching Method has been known as an accurate and reliable method for numerical analysis not only on the diffraction problem in the electromagnetic field, but also on the elastic waveguide and the optical thin‐film waveguide. This method is applied for the rigorous analysis of an elliptically‐cored optical fiber with large ellipticity whose accurate analysis in the wide range of frequency including the cutoff has so far been difficult. Moreover, a very high degree of accuracy of five figures is achieved for the normalized propagation constant. Both the dispersion relation and the field distribution in the hybrid modes are clarified and it is also confirmed that the hybrid mode analysis is not always necessary in the case of larger ellipticity. The properties of the higher‐order mode cutoff and the polarization preservation whose rigorous discussion has not been always sufficient, are analyzed more accurately. The results are compared with the results obtained by other methods, and more exact design data for the single mode, polarization‐preserved optical fiber with elliptical core are presented. Through these analyses, it is also confirmed that the Mode‐Matching Method is still a useful and reliable method for rigorous analysis of the rod‐type dielectric waveguide with arbitrarily shaped cross section.

Effect of the metallisation thickness and mounting grooves on the propagation characteristics and bandwidth of finlines

The influence of finite metallisation thickness and mounting grooves on the millimetre-wave characteristics of unilateral and bilateral finlines has been studied in detail. A fully hybrid mode analysis has shown that the influence of the metallisation thickness depends on the frequency, the dielectric material and the gap width. Differences between the dominant mode dispersion in unilateral and bilateral finlines become evident. The influence of the mounting grooves on the dominant finline mode is negligible as long as the grooves are not deeper than half the waveguide height and the operating frequency remains in the lower two-thirds of the waveguide band. However, the higher-order modes are strongly affected even by very shallow grooves, which leads to a significant reduction of the single mode bandwidth.

Calculating the Characteristic Impedance of Finlines by Transverse Resonance Method

The characteristic impedance of finlines with up to three slots is calculated by a rigorous hybrid-mode analysis which includes the finite metallization thickness and finite depth of the mounting grooves. The transverse resonance principle utilized reduces considerably the order of the involved matrix eigenvalue problem. The propagation constants for the fundamental HE/sub 1/ mode (and EH/sub 0/ mode at related structures), as well as for the higher order modes (up to HE/sub 7/), and the characteristic impedances for the fundamental modes are computed as a function of frequency for the bilateral and unilateral finline, as well as for the unilateral finline with two coupled slots, and an additional slot on the opposite side of the substrate surface. The finite metallization thickness and mounting groove depth considered show significant influence on the behavior of the characteristic impedance.

A Modified Mode-Matching Technique and its Application to a Class of Quasi-Planar Transmission Lines

A rigorous and versatile hybrid-mode analysis is presented to determine the normalized propagation constants in a class of quasi-planar transmission-line structures. The method is accurate and covers the finite metallization thickness, mounting grooves, and an arbitrary number of dielectric subregions. Utilizing a modified mode-matching technique, one can derive discontinuity and transmission-line matrices for each homogeneous subregion. Successively multiplying matrix equations of all subregions leads to the characteristic matrix system. This procedure makes it possible to create a modularized computer program which can be conveniently extended to a wide spectrum of conceivable configurations simply by inserting the matrix equations of additional subregions in the multiplication process. To demonstrate the efficiency of the proposed method, dispersion characteristics of dominant and next higher order hybrid modes in earthed and insulated finlines, suspended microstrips, and coupled striplines with tuning septa, are given as examples.

Rigorous Hybrid-Mode Analysis of the Transition from Rectangular Waveguide to Shielded Dielectric Image Guide

The transition waveguide to shielded and dielectric image guide is analyzed by the rigorous hybrid-mode field expansion technique where higher order mode coupling effects are taken into account directly, also below the corresponding cutoff frequency. The solution of the related eigenvalue problem includes waves with a complex propagation constant although the guide is assumed to be lossless. Calculated diagrams of the propagation constant as a function of frequency, as well as of the permittivity, illustrate the complicated mode conversion between evanescent modes, complex waves, backward waves, and propagating waves. For the three-dimensional scattering problem, the calculated magnitude of the input reflection coefficient agrees well with measurements, whereas the transmission-line theory applied to this structure leads to wrong results.

Hybrid-Mode Analysis of Coupled Microstrip-Slot Resonators

An advanced microwave and millimeter-wave integrated circuit element, that is, a coupled microstrip resonator with a tuning slot, or a coupled microstrip-slot resonator, has been developed. As speciaf cases, a microstrip-slot resonator, coupled microstrip resonator, and microstrip resonator have been investigated. A hybrid-mode analysis is presented for obtaining resonant frequencies. It is based upon Galerkin's method in the Forier transform domain. The Green functions in this domain, which are versatile and applicable to other microstrip-slot structures, are shown in simple form. Computed resonant frequencies and measured resonant values are compared for aluminum substrates in the 3-7-GHz frequency range.

Hybrid-Mode Analysis of Arbitrarily Shaped Planar Microwave Structures by the Method of Lines

This paper presents a method for analyzing arbitrarily shaped planar microwave structures, which is based on the method of lines and applies to both resonant and periodic structures in microstrip, slotline, and finline circuits. Numerical results are presented for some selected structures.

Hybrid-mode analysis of a broadside-coupled microstrip line

The purpose of the paper is to present a hybrid-mode analysis for obtaining dispersion characteristics of a broadside-coupled microstrip line. A characteristic equation for a propagation constant is derived via Galerkin's method in the Fourier-transform domain. It is shown that the dependence of the solution on the basis functions is small. Computed effective dielectric constants in the low-frequency region agree well with other investigators' numerical results, which are based upon the quasi-TEM method. Finally, dispersion characteristics, which are important in practical design, are demonstrated.

Erratum: Theoretical analysis of hybrid modes in a dual-depth corrugated waveguide feed

Erratum: Theoretical analysis of hybrid modes in a dual-depth corrugated waveguide feed

Theoretical analysis of hybrid modes in a dual-depth corrugated waveguide feed

The propagation behaviour of dual-depth corrugated feeds is considered with particular reference to application of such structures for frequency reuse applications in satellite communication antennas. Results are presented which enable a feed to be designed operating under balanced hybrid condition at two predetermined frequencies. It is shown that at the higher balanced hybrid frequency the EHmn modes radiate with a maximum on axis with zero crosspolarisation, whereas at the lower balanced hybrid frequency the HEmn modes show these characteristics.

Hybrid-mode analysis of a microstrip-slot resonator

A hybrid-mode analysis is presented for obtaining resonant frequencies of a microstrip resonator with a tuning slot; namely, a microstrip-slot resonator, which has a microstrip and a tuning slot on each side of the substrate, respectively, and whose special case is a microstrip resonator. The analysis is based upon Galerkin's method in the Fourier transform domain. The sensitivity of the solution is investigated with respect to the basis functions. The computed resonant frequencies, using simple basis functions, are compared with the experimental values on alumina substrate in the frequency range 3–7 GHz.

Hybrid Mode Analysis of Microstrip Lines on Anisotropic Substrates

A rigorous hybrid mode analysis is applied to microstrip lines on anisotropic substrates to determine its high-frequency performance. The analysis is based on a general formulation of the problem of planar transmission lines on multilayered substrates with uniaxial anisotropy, of which the microstrip line is a special case. Exact solution is obtained using a functional equation technique which was previously developed and applied to microstrip and bilateral finlines. The results were used to check the validity of the concept of equivalent isotropic substrate, suggested by some authors to simplify the calculation of the parameters of these lines. Certain approximations are introduced to allow the efficient calculation of the characteristics of microstrips on anisotropic substrates at relatively high frequencies or for wide strips. Numerical results are given for some values of the parameters of microstrip lines on sapphire and include the regions of excitation of higher modes.

Theoretical analysis of hybrid modes of magnetooptical wave-guides

Anisotropic dielectric optical wave-guides can be used in integrated optics to make reciprocal and non reciprocal devices. The optical modes of such guides are calculated by the exact resolution of macroscopic Maxwell equations for an anisotropic dielectric waveguide. For the special case of magnetooptical guides the mode behaviour is analysed and compared to the classical isotropic guides. Main properties of magnetooptical guides, such as non reciprocity and degeneracy of the modes, are studied. These results can be used to optimise different film parameters and to improve the experimental performances of integrated optics devices. Les guides d'ondes optiques diélectriques et anisotropes peuvent ětre utilisés en optique intégrée pour réaliser des systèmes réciproques et non réciproques. Les modes propres de propagation ont été calculés à partir de la résolution exacte des équations de Maxwell macroscopiques dans un guide d'onde optique diélectrique et anisotrope. Les caractéristiques des modes ont été analysées dans le cas particulier d'un guide d'onde magnétooptique et comparées à celles d'un guide d'onde isotrope classique. Les propriétés essentielles des guides d'onde magnétooptiques, telles que la non réciprocité et al dégénérescence des modes, ont été étudiées. Ces résultats peuvent ětre utilisés pour optimiser les différents paramètres du film et améliorer les performances des dispositifs d'optique intégrée.

Hybrid mode analysis of end effects of planar microwave and millimetrewave transmission lines

Hybrid mode analysis of end effects of planar microwave and millimetrewave transmission lines

Spectral Domain Solution of Arbitrary Coplanar Transmission Line with Multilayer Substrate (Short Papers)

A hybrid mode analysis is presented for a multilayer dielectric within a rectangular conducting box. An arbitrary set of conductors may be distributed along the lower surface of the top layer, so that single or coupled forms may be analyzed of slot line, microstrip, or coplanar waveguide. The analysis combines a transfer-matrix approach with the spectral domain method to give a versatile and efficient solution. CPU time on an IBM 360/65 is about 1 s per layer of substrate, for a single slot or strip, at one frequency.