基于硅氧化层的嵌入式传输线制造

在有损耗的硅衬底上试制了传输线(微带以及共面波导),并嵌入在CMOS Cu/SiO2互连层中.对传输线的几何尺寸与其特征阻抗、损耗以及衰减因子进行了研究.结果表明嵌入在硅氧化层中的微带和共面波导可以在有损耗的硅片上低损耗地实现,为在硅片上设计微波和毫米波电路提供了必要的无源器件.     

Closed-form expressions for the series impedance parameters of on-chip interconnects on multilayer silicon substrates

This paper presents accurate closed-form expressions for the frequency-dependent series impedance parameters of on-chip interconnects over general multilayer conductive silicon substrates. The closed-form expressions are obtained from a generalized complex image approach combined with a surface impedance formulation that takes into account the effects of the distributed eddy currents in the multilayer conductive substrate. Results for single and coupled microstrips on multilayer conductive substrates are shown over a broadband frequency range of 20 GHz and compared with full-wave electromagnetic solutions. It is demonstrated that a thin, heavily-doped channel-stop layer may contribute significantly to the series resistance at higher frequencies. The new approach is further validated for a coplanar waveguide interconnect by comparison with measurement data.     

Numerical Analysis of Shielded Coplanar Waveguides

A numerical method is presented to calculate the impedance and the effective dielectric constant for a coplanar waveguide with a ground plane under a thin dielectric. Impedance and effective dielectric constant values are given as a function of geometry for GaAs and alumina substrates. An approximate analytical expression is given to generate the numerical value of the impedance with good accuracy. The results can be used in designing shielded coplanar waveguides. Measurements of a tapered 50-Omega test structure are presented.     

Analysis of bilateral coplanar waveguides printed on anisotropicsubstrates for use in monolithic MICs

The spectral-domain method is applied to the analysis of bilateral (double-sided) coplanar waveguides that are printed on electric and/or magnetic anisotropic substrates. A nondecoupling approach is used to solve the coupled differential equations for the transverse propagation constants inside the substrate. The dyadic admittance Green's function is derived for both open and shielded bilateral coplanar waveguides, taking into account the anisotropy of the material. Finally, numerical results, describing the propagation characteristics of these structures, are presented for both electric and magnetic wall symmetries     

The Reflection Definition of the Characteristic Impedance of Microstrips

The frequency-dependent characteristic impedance shielded microstrips is computed by the scattering matrix of the step of rectangular transmission line to the shielded microstrip including higher order hybrid modes. This method avoids the ambiguities of the hitherto known definitions based on TEM quantities. For the dispersion characteristics a resonant model is used which reduces the number of the characteristic equations required. Numerical results are given including strips of finite thickness placed unsymmetrically in the shielded microstrip.     

Full wave analysis of conductor-backed and multi-layer high-T c superconducting coplanar waveguide

Dispersions, attenuation and characteristic impedance of shielded conductor-backed coplanar waveguide(CBCPW) and shielded three-layer coplanar waveguide (CPW) with finite conductor thickness as well as their superconducting applications are calculated. The method of lines(MoL) is employed to analyze these coplanar waveguides. The analysis is validated by a comparison of the calculated results with those published previously. Effects of finite width of grounded strip for a CPW are considered. Extensive investigation of the numerical convergence for calculation of the characteristic impedance is also described.     

用2.5维的边缘元法分析屏蔽导波结构中含非匀质基片的微带线

微波单片集成电路（MMIC）的优化设计已受到工业界的关注，而MMIC元件广为采用含非匀质基片的微带线。用2．5维的边缘元法研究了这类屏蔽导波结构的色散特征，所导出的公式适用于各种复杂形状的导波结构。对某些简单结构，该结果与用其它解析和数值方法得出的数据相符；对某些复杂结构，提供的新结果预示了扩展应用的可能性。     

An analytical solution for the coupled stripline-like microstripline problem

An analytical method is presented for determining the Maxwell's capacitance matrix of multiconductor shielded microstrips with coupled conductors of arbitrary widths, spacings, and inhomogeneous media, in terms of elliptic integrals. The method is based on conformal mapping and the theory of singular integral equations. Two kinds of problems are presented as examples: the first consists of simple structures with one or two coupled striplines; the other type concerns the general case of multiconductor coupled structures for which simple analytical expressions are not available     

Through-silicon-chip transmission lines

Through-chip transmission lines connecting the frontside and backside of high-resistivity wafers are fabricated using bulk-micromachining and backside metal patterning. Experimental results illustrate the feasibility of low-loss through-chip microstrips and coplanar waveguides for innovative integration concepts of radio-frequency and microwave systems in silicon technology     

A Unified Variational Solution to Microstrip Array Problems

A very general variational procedure is used to compute single or coupled microstrips under the quasi-TEM approximation. The capacitance model is found by means of a unique fundamental cell. The method is essentially an extension of Smith's, but may be used to study a wider variety of problems, such as nonuniform strip arrays, coplanar striplines, and broad-side coupled strips. Moreover, it is also possible to compute the coupling capacitance between nonadjacent strips.     

Tolerance Analysis of Shielded Microstrip Lines (Short Paper)

A complete analysis of the sensitivities of shielded microstrips is presented. The sensitivity formulas form the basis for studying the effect of tolerances on the performance of these circuits. A set of sensitivity curves are given to help the design procedure. It is suggested that the position of the top cover can be adjusted to compensate for some of the effects of the manufacturing tolerances. Practical examples are given to support the suggested procedure.     

Characterization of shielded coplanar type transmission linejunction discontinuities incorporating the finite metallizationthickness effect

Frequency-dependent characteristics of shielded junction discontinuities between coplanar type transmission lines, specifically coplanar waveguide (CPW) and finline, are analyzed by the mode-matching technique. The effect of finite metallization thickness is also incorporated in the analysis for the first time. Scattering parameters of finline step discontinuity are compared with existing data to confirm the accuracy of the approach. Numerical results for finline step discontinuity, shielded CPW step discontinuity and CPW-finline transition are presented     

Spectral domain form of new variational expression for very fastcalculation of multilayered lossy planar line parameters

A new spectral domain formulation of the propagation characteristics for planar and coplanar lines is presented. It is based on a newly established variational principle, valid for a spatial as well as for a spectral formulation. In combination with conformal mapping, it drastically reduces the complexity of the numerical computation and leads to rapidly convergent results even when higher order modes are considered. Mathieu functions are shown to be very efficient expressions for trial fields of the dominant and the higher order modes in slots. Calculation is fast: it is made on-line on a regular PC. Results obtained on open and shielded lines have been successfully checked with new experimental data and with previously published data. The method is general enough to accommodate gyrotropic substrates. The paper however is limited to isotropic media     

衬底材料对微带线间串扰耦合的影响研究

随着系统频率的提高,衬底材料特性已成为影响信号走线之间串扰的一个不可忽略的因素。该文基于传输线方程和频域S参数对两平行微带线间串扰耦合进行理论分析,并结合全波3维电磁场仿真工具对具有不同介电常数和不同厚度的衬底材料进行了仿真和分析,得到了微带线在不同衬底下的电场分布,以及近端和远端串扰随频率、衬底介电常数和厚度变化的曲线。随着频率的增大,远端串扰将大于近端串扰,并且随着衬底介电常数和厚度的增加,微带线间的串扰呈现正弦上升的变化趋势。     

Printed Circuit Transmission-Line Characteristic Impedance by Transverse Modal Analysis

Dispersion characteristics of printed circuit transmission lines such as finlines, shielded microstrips, slotlines, suspended striplines, coupled slotlines, and coupled striplines computed by the transverse modal analysis were reported in a previous paper. Application of the transverse modal analysis to compute the characteristic impedances of these printed circuit transmission lines is illustrated in this paper. Favorable comparison with various published data demonstrates the outstanding accuracy achieved by this technique. Combining the characteristic impedance computation with the dispersion results, the transverse modal analysis can be employed for solving various problems in printed circuit transmission lines.     

Study of radiating properties of open-ended rectangular waveguides

The transverse-operator method has been applied to analyze the behavior of an open-ended rectangular waveguide as a radiating element. The method offers the advantage of simple and systematic formulation of the problem, particularly in the case of discontinuities, whether they are radiating (in dielectric waveguides, microstrips, etc.) or in shielded structures (ridged waveguides, partially filled waveguides, etc.). The numerical results concerning the admittance and power patterns of a waveguide aperture surrounded by an infinite conducting flange are compared to those available in the literature, and a good agreement is observed     

Dispersion in shielded coupled coplanar waveguides

A full-wave solution is developed to investigate the dispersion in shielded coupled coplanar waveguides. This study shows that the quasi-TEM data available in the literature for the coupled coplanar waveguide cannot accurately predict the performance of this structure at high frequencies.     

Performance of Microstrip Couplers on an Anisotropic Substrate with an Isotropic Superstrata

The directivity of microstrip couplers on anisotropic substrates can be improved substantially by adding an isotropic superstrata layer above the microstrips. The necessary dimensions of the layer can be chosen so that fabrication is simple and noncritical.     

Generalized spectral-domain analysis for multilayered complex mediaand high-Tc superconductor applications

An efficient algorithm for rigorously deriving the spectral-domain impedance dyadic Green's function for MMICs on general complex anisotropic or bi-anisotropic substrates is developed. Its main advantage is that it provides closed-form expressions for transverse propagation constants and related immittances in the spectral domain and, therefore, allows the following parameters to be taken into account: dielectric and magnetic losses of anisotropic or bi-anisotropic media without restrictions to the magnitude of tensor elements, alternative directions for magnetic bias, and the finite metallization thickness of conventional conductors and/or superconductors including their losses. Microstrip and coplanar waveguide structures in open, shielded, and conductor-backed technology can be treated. The theory is verified by comparison with previously published data, and its flexibility is demonstrated for both superconductor and conventional conductor (M)MIC structures     

Effect of coplanar probe pad design on noise figures of 0.35 μmMOSFETs

The effects of different coplanar ground-signal-ground (GSG) probe pads on the noise figure characteristics of submicron MOSFETs are presented. Devices with top-level metal as probe pads shielded by grounded bottom-level metal possess the most appropriate probe pad structure for characterising the noise performance of MOSFETs. Equivalent circuits of the probe pads are used to explain the different noise behaviours