Parameters of asymmetrical co-planar striplines with finite substrate thickness

Analytical formulae for the quasi-TEM parameters of an asymmetrical co-planar stripline with finite substrate thickness are obtained from those of the infinite-thickness structure. Their accuracy is verified by a comparison between the calculated and available results for the specially symmetrical case. In addition, these line parameters are calculated approximately by simulating an asymmetrical co-planar line with two symmetrical lines. Good agreement is obtained for a wide range of geometric parameters.     

Analysis of shielded striplines and finlines with finitemetallization thickness containing magnetized ferrites

The applicability of the spectral domain approach is extended to analyze various types of shielded planar transmission lines, taking the anisotropy of the magnetized ferrites and the finite metallization thickness into consideration. The numerical computations include the propagation characteristics of finlines and striplines and the metallization thickness effect in these lines. Numerical data of simpler structures are compared with the available exact solution as well as with published data     

Transmission characteristics of suspended striplines with finite metallisation thickness and substrate supporting grooves

This letter presents an accurate hybrid-mode analysis of suspended striplines with finite metallisation thickness and substrate supporting grooves. Particular attention is paid to the calculation of the characteristic impedance. The significant effects of finite metallisation thickness and substrate supporting grooves on the transmission characteristics of suspended striplines are revealed in the higher frequency range.<>     

Metallization thickness in bilateral and unilateral Finlines

The theory and numerical results are presented to the effective dielectric constant and characteristic impedance of bilateral and unilateral finlines with metallization thickness. The full wave analysis of the transverse transmission line — TTL method is used to determine the electromagnetic fields of the structure in Fourier transform domain — FTD. Applying the suitable boundary conditions and the moment method, a homogeneous matrix system is obtained and the effective dielectric constant is extracted. The characteristic impedance is obtained using the relation between the voltage in slot and the transmitted power. Computational programs are developed to obtain numerical results to the effective dielectric constant and characteristic impedance.     

Conformal mapping analysis of shielded striplines

The method of conformal mapping is used to modify shielded stripline configurations into that of a strip over an infinite ground plane. Results known for the latter structure allow the evaluation of the stripline parameters. This formulation applies to narrow strips located both symmetrically and asymmetrically inside the shielding.     

Characteristics of striplines with inhomogeneous cylindrical substrate

A mode-matching technique combined with Galerkin's method is proposed in this paper to analyze the characteristics of striplines embedded in an inhomogeneous cylindrical medium. The potential in each layer is expressed in terms of eigenmodes obtained numerically. Coupling between two sets of eigenmodes in contiguous layers is described by defining potential ratio coefficient matrices. An integral equation is derived based on these eigenmodes with charge on the stripline as unknown. The method of moments is then applied to solve this integral equation. Various parameters are analyzed for their effects on transmission characteristics.     

Analysis of coupled cylindrical striplines filled with multilayereddielectrics

A method of analysis for coupled cylindrical striplines filled with multilayered dielectrics is presented that uses a variational technique in the space domain. Coupled-mode analysis is presented for the case of a pair of coupled circular arc strips arbitrarily located between cylindrical ground planes filled with multilayered dielectrics. An even and odd-mode approach is used for the analysis of shielded cylindrically curved edge-coupled pairs of broadside parallel strips (broadside, edge-coupled cylindrical striplines). The effect of environmental changes on an otherwise planar structure is also studied by extending the present analysis to cylindrically warped coupled striplines     

Quasi-static solutions of multilayer elliptical, cylindrical coplanar striplines and multilayer coplanar striplines with finite dielectric dimensions - asymmetrical case

In this paper, fast, accurate, and simple analytic closed-form expressions are presented in order to calculate the quasi-TEM parameters of multilayer elliptical coplanar stripline (CPS), multilayer cylindrical CPS, and multilayer CPS, with finite dielectric dimensions by using conformal mapping techniques. The obtained computer-aided-design-oriented expressions are quite accurate and easy to apply in designing microwave integrated circuits and antenna applications. The results have also been compared with the ones of another conformal mapping method available in the literature and also confirmed analytically.     

Design and performance of the magnetic hybrid-mode horn

Design techniques are presented for a class of circular magnetic hybrid-mode (MHM) horns together with experimental results. In comparison with earlier techniques, this design method is simpler and more amenable to physical interpretation. The horns designed exhibit performance comparable to that of the corrugated horn except that they have an ohmic loss of 0.8 to 2.7 dB. However, it appears feasible to reduce the gain loss to less than 1 dB     

Design and simulation of metamaterial-based hybrid-mode horn antennas

The design and analysis of novel hybrid-mode soft and hard horn antennas with a low index metamaterial wall liner are presented. Metamaterial horn antennas have the potential for considerably larger bandwidth than the current state-of-the-art horns. The optimal or required metamaterial dispersion curve for these horns is qualitatively similar to the Drude dispersion, which indicates that the metamaterial horns are realisable.     

Circular cylindrical waveguide filled with uniaxial anisotropicmedia electromagnetic fields and dyadic Green's functions

Electromagnetic fields in a circular cylindrical conducting waveguide filled with uniaxial anisotropic media are formulated in this paper by using Fourier transformations. These fields are obtained as a superposition of the TE (or ordinary) and TM (or extraordinary) modes satisfying, respectively, different characteristic equations. Lastly, the dyadic Green's function is derived using the Ohm-Rayleigh method and represented by vector wave functions expansion     

Performance analysis of MIMO systems with antenna selection over quasi-static fading channels

We analyze the performance of multiple-input-multiple-output (MIMO) systems with antenna selection over quasi-static fading channels. The basic idea is that, for a given number of receive antennas, M, the receiver uses the best L out of the available M antennas where, typically, L相似文献   

Partial-boundary element method for analysis of striplines witharbitrary cross-sectional dielectric in multi-layered media

A new method of analysis called the partial-boundary element method (p-BEM) is proposed for the analysis of striplines with arbitrary cross-sectional dielectric in multi-layered media. By using a Green's function that satisfies the boundary conditions of a relevant structure with multi-layered media and introducing a concept of the equivalent charge density, the p-BEM formulates a potential integral and boundary integral equations only on partial-boundaries such as the surface of the arbitrary cross-sectional dielectric. The number of the equations needed to be formulated is much less than in the conventional BEM. Numerical results of analysis are presented for two kinds of striplines: 1) with a rectangular dielectric ridge and 2) with an embedded rectangular dielectric in three-layered media     

Dealing with hysteretic sensors: investigation on quasi-static behavior

Piezoelectrics, ferroelectrics, and ferromagnetics show hysteretic (intrinsically nonlinear) input-output characteristics. The interest in understanding the behavior of hysteretic devices is due to their useful characteristics, especially when used as detectors. This article studies the quasi-static behavior of hysteretic devices.     

A signal/noise analysis of quasi-static MR elastography

In quasi-static magnetic resonance elastography, strain images of a tissue or material undergoing deformation are produced. In this paper, the signal/noise (S/N) ratio [SNR] of elastographic strain images, as measured by a phase-contrast technique, is analyzed. Experiments are conducted to illustrate how diffusion-mediated signal attenuation limits maximum strain SNR in small displacement cases, while the imaging point-spread function limits large displacement cases. A simple theoretical treatment agrees well with experiments and shows how an optimal displacement encoding moment can be predicted for a given experimental set of parameters to achieve a maximum strain SNR. A further experiment demonstrates how the limitation on strain SNR posed by the imaging point-spread function may potentially be overcome.     

回流加固结构金属化系统的可靠性测试

结合器件具体结构和工艺,在回流效应理论和实验研究的基础上优化设计了回流加固结构。产一套和地回流加固结构样管进行了电热加速应力试验,考核了不同结构的加固效果及抗热电迁徒性能,优选了最佳回流结构。     

Neural models for quasi-static analysis of conventional and supported coplanar waveguides

Neural models based on multilayered perceptrons (MLPs) for computing the effective permittivities and the characteristic impedances of both the conventional coplanar waveguides (CCPWs) and the supported coplanar waveguides (SCPWs) are presented. Six learning algorithms, Levenberg–Marquardt (LM), Bayesian regularization (BR), quasi-Newton (QN), scaled conjugate gradient (SCG), conjugate gradient of Fletcher–Powell (CGF), and resilient propagation (RP), are used to train the MLPs. The results of neural models presented in this paper are compared with the results of the experimental works, the conformal mapping technique (CMT), the spectral domain approach (SDA), and three commercial electromagnetic simulators such as IE3D, CAPIND2D, and MMICTL. The neural results are in very good agreement with the theoretical and experimental results. When the performances of neural models are compared with each other, the best result is obtained from the MLPs trained by the LM algorithm.     

Analysis of dispersion and series gap discontinuity in shieldedsuspended striplines with substrate mounting grooves

Dispersion and series gap discontinuity of shielded suspended striplines (SSLs) on Duroid substrate (ϵ_r=2.22) are analyzed using the finite-difference time-domain method (FD-TD). Numerical accuracy of better than 0.15% is achieved when the FD-TD is used to calculate the effective dielectric constant (ϵ_reff ) of an air-filled rectangular coaxial transmission line. Data obtained for the frequency-dependent ϵ_reff of uniform SSLs and both scattering and equivalent circuit parameters of various series gap discontinuities are presented. In general, the presence of sidewall mounting grooves causes a nearly frequency-independent small reduction in ϵ_reff. On the other hand, proximity effects of the housing are found to be more important. For the gap discontinuity, coupling across the gap is stronger for wider strips and/or narrower gap width. Irregular transmission behavior is also found when the strip is wide enough to interact strongly with the sidewalls     

Modeling of striplines between a power and a ground plane

In this paper, a stripline model is presented for coupled signal lines routed between a power and a ground plane based on multiconductor transmission line (MTL) theory. Through a suitable diagonalization of the MTL equations for striplines, the transverse electromagnetic (TEM) parallel-plate mode is decoupled from the stripline mode. In this way, stripline models that are obtained assuming ideal planes at ground potential can be extended to take into account the nonideal behavior of the planes. The presented model is applied to represent mode conversion due to vias, holes in the reference planes, and terminations of the stripline. Influence of inhomogeneous media is discussed.