Theoretical and experimental characterization of coplanar waveguidediscontinuities for filter applications

A full-wave analysis of shielded coplanar waveguide (CPW) two-port discontinuities based on the solution of an appropriate surface integral equation in the space domain is presented. Frequency-dependent scattering parameters for open-end and short-end CPW stubs are computed using this method. The numerically derived results are compared with measurements performed in the frequency range 5-25 GHz and show very good agreement. From the scattering parameters, lumped-element equivalent circuits have been derived to model the discontinuities. The inductors and capacitors of these models have been represented by closed-form equations, as functions of the stub length, to compute the circuit element values for these discontinuities     

硅衬底RF集成电路中螺旋电感的建模和分析

对硅衬底RF集成电路中的螺旋电感进行电磁场建模,考虑了衬底损耗效应,并通过电路分析和网络分析技术得到了二端口简化电感模型.该模型在特定的截止频率以下可提供可靠的电路系统仿真.利用该模型分析了硅衬底的损耗对螺旋电感品质因素(Q)的影响.     

A comprehensive compact-modeling methodology for spiral inductors in silicon-based RFICs

A new comprehensive wide-band compact-modeling methodology for on-chip spiral inductors is presented. The new modeling methodology creates an equivalent-circuit model consisting of frequency-independent circuit elements. A fast automated extraction procedure is developed for determining the circuit element values from two-port S-parameter measurement data. The methodology is extremely flexible in allowing for accurate modeling of general classes of spiral inductors on high- or low-resistivity substrate and for large spirals exhibiting distributed trends. The new modeling methodology is applied to general classes of spirals with various sizes and substrate parameters. The extracted models show excellent agreement with the measured data sets over the frequency range of 0.1-10 GHz.     

Modeling of double-π equivalent circuit for on-chip symmetric spiral inductors

We present a novel methodology to extract model parameters from measured S-parameters for silicon on-chip center-tapped symmetric spiral inductors. The double-π equivalent circuit topology is employed in which conductor skin effect is considered. The automated extraction procedure based on modified differential evolution is demonstrated to be efficient and effective. To verify the accuracy of the new methodology, 17 center-taped symmetric inductors were fabricated and the equivalent circuit parameters were extracted from two-port S-parameters measurements over the frequency range of 0.3–8.5 GHz. The excellent accuracy of the results demonstrates the flexibility of the modeling methodology. The new methodology should be useful in the design of RF ICs and mixed signal ICs.     

S-parameter formulation of quality factor for a spiral inductor in generalized two-port configuration

This paper formulates various quality (Q) factors associated with the applications of on-chip spiral inductors to radio-frequency integrated circuits using S-parameters. The formulations start with the Q factor of a spiral inductor in a generalized two-port configuration based on a new complex-power approach and then extend to the Q factors of a tank and matching circuits that use the spiral inductors. In the demonstration, the two-port S-parameters for a series of CMOS spiral inductors have been measured to further generate such various Q factors for a many-sided evaluation of the inductor performance.     

关于互易二端口网络互连的讨论

互易电路及二端口电路互连是电路课程教学中的重要内容。本文讨论了互易二端口电路互连后总二端口电路的互易性,给出了一般性结论及证明,即互易二端电路互连后如仍满足端口定义,则互连后的总二端电路仍然是互易的。对于对称二端电路,也有类似的结论。本文的讨论对电路课程的教学具有一定的参考价值。     

The triamplifier, a new circuit element, and its use in active filters

A new operational amplifier circuit building block-the triamplifier-is described. This is basically a symmetrical amplifier with three inputs and three outputs. The triamplifier can be used to realize high-performance floating inductors, and appears to offer significant advantages over alternative circuits.     

基于改进1-π拓扑结构的螺旋电感可扩展模型

随着射频集成电路空前发展,电感作为射频电路中重要无源器件应用越来越广.目前其仿真模型应用频率范围较窄并且仿真结果与测试结果拟合较差.本文提出了基于0.13μm SOI CMOS工艺的片上螺旋电感修改模型.模型采用了1-π等效电路,包含有表征衬底涡流的RL并联网络并且改进了由趋肤效应引起的金属线圈中涡流的表征.利用数理统计中的回归分析方法,得到扩展模型参数的表达式.制备了13种不同尺寸的片上螺旋电感用于验证模型.本文提出的方法,对不同尺寸的电感在频率达到自谐振频率以上的行为提供了更好的电路解释.     

模拟电子电路的两端口网络阻抗等效变换

模拟电子技术中的很多基本电路都可视为三端子两端口网络。在学习过程中,为有效分析其输入-输出特性,往往需要对其进行输入回路和输出回路的拆分式解耦等效分析,而阻抗参数等效变换成为一大难点。基于电路理论基础知识,对三端子两端口网络的串联式和并联式阻抗参数等效变换进行了详细推导,并将所提的参数等效变换方法应用于三个典型模拟电路的特性分析,有效简化了电路分析过程。     

耦合腔慢波结构的特性分析

计算耦合腔慢波结构特性的方法很多,但是直接计算还比较困难,主要是因为耦合腔复杂形状造成的。等效电路方法是一个非常有效的、快速计算耦合腔色散特性和无损、有损耗情况下各个耦合腔电压、电流分布的方法。损耗是通过在电路中引入与电感串联的电阻。时域分析有利于单一频谱和所有频谱的瞬态分析和开启瞬态分析。     

An adaptive impedance tuning CMOS circuit for ISM 2.4-GHz band

The difficulties encountered in matching an antenna to its optimal impedance are reduced with an adaptive 0.35-/spl mu/m CMOS circuit based on several switched shunt capacitors arranged in capacitor banks and on a few external series inductors. As high-quality inductors are difficult to obtain in CMOS, the inductors are placed either in an low-temperature cofired ceramic (LTCC) substrate or is a lumped component outside the core circuit. The circuits, presented here through a range of simulations, are optimized to function within the ISM 2.4-GHz band, but the general approach employed to improve matching can be used for other frequency bands as well. The circuits discussed provide a VSWR/spl les/2 match for every impedance with VSWR/spl les/5. There is a 1-dB power loss for a perfect 50 /spl Omega//spl rarr/50 /spl Omega/ transformation, a break-even point at VSWR=1.5, and a 3-dB increase in delivered power for VSWR= 4.3.     

A Design Method for Meander-Line Networks Using Equivalent Circuit Transformations

Many types of coupled structures are used to design microwave filters and equalizers. One such structure is the array of coupled parallel commensurate conductors called a meander line. There are several analysis techniques that may be used to find the equivalent circuit of a meander line. However, these do not provide exact design equations. In this paper, meander-line networks are analyzed and synthesized using the graph-transformation technique. The equivalent circuits of one- and two-port meander-line networks will be developed by using the transformation method, and it will be shown that meander-line networks can be easily designed by using the electronic computer.     

Modeling skin and proximity effects with reduced realizable RL circuits

On-chip conductors such as clock- and power-distribution networks require accurately modeling skin and proximity effects. Furthermore, to incorporate skin and proximity effects in the existing generic simulation tools such as SPICE, simple-frequency independent-lumped element-circuit models are needed. A rule based RL circuit model is proposed in this paper that is realizable and predicts skin and proximity effects accurately in the frequency range of interest. With this circuit model, wires are characterized by a few parallel branches of resistors and inductors while proximity effect is captured by mutual inductance between inductors in different RL circuits.     

Equivalent Circuit of a Narrow Axial Strip in Waveguide (Short Papers)

A theoretical determination is made of the two-port equivalent circuit of a narrow strip located axially in a rectangular waveguide such that it extends partially or completely across the waveguide narrow dimension. The analysis is based upon derivation of a variational expression for a field quantity from which can be determined the reflection coefficient and the equivalent-circuit parameters. Experimental input susceptance values agree closely with the theory. The analysis shows that the T-equivalent network of a nontouching strip has a series-resonant shunt circuit. This element has application in filter and impedance-transforming networks, in planar circuits, and in fin-line structures.     

含全耦合电感电路的求解

分析动态电路既可以应用拉普拉斯变换方法,也可采用时域分析方法。通过分析含全耦合电感电路,得出流入耦合电感的电流有可能发生跃变的结论,该电流不是电路的状态变量。对含全耦合电感电路的求解以拉普拉斯变换方法为宜。如果采用时域分析方法,则应采用含全耦合电感电路的等效电路来求解。上述分析结果可供讲授电路理论的教师参考。     

Investigation of a multigigahertz MOSFET amplifier with an on-chipinductor fabricated on a SIMOX wafer

This paper describes a technology that can be used to integrate multigigahertz RF circuits into large-scale digital circuits. Spiral inductors and a MOSFET amplifier with an inductive load were fabricated on a SIMOX wafer in order to demonstrate the feasibility of SOI technology. With a 1-V supply voltage, peaking of the amplifier gain was observed, as expected from circuit simulations, at 1-4 GHz. These results show that RF circuits with inductors can be implemented on a SIMOX wafer by using the conventional digital CMOS LSI process     

Four-phase power clock generator for adiabatic logic circuits

A circuit for a four-phase trapezoidal power clock generator for adiabatic logic circuits realised with a double-well 0.25 μm CMOS technology and external inductors is proposed. The circuit, at a frequency of 7 MHz which is within the optimum frequency range for adiabatic circuits realised with 0.25 μm CMOS technology, has a conversion efficiency higher than 80%, and is robust with respect to parameter variations     

基于组合联接双微波二端口网络的噪声分析

大多数微波电路可以用一个二端口网络或者多个二端口网络相互联接的方法进行模拟和分析，二端口网络方法比节点分析法更加简洁，且便于快速计算。基于简单联接二端口网络的微波电路噪声分析并提取噪声参数有很重要的应用价值。本文将对两种组合联接的微波二端口网络进行噪声分析，并给出相应的结论。     

A Practical Tantalum Thin-Film Single-Sideband Demodulator Using RC Time-Varying and Active Networks

The thin-film circuit described in this paper is equivalent to a demodulator circuit containing an extremely selective filter ("sideband" filter). Such a filter would, in conventional form, require very high Q inductors or, as the Q requirement increases, the use of crystal or mechanical filters. At the frequency of operation of this circuit (1 MHz), demodulation with conventional filters would have to be accomplished in two or more stages so that the selectivity requirement can be decreased for each filter. Thin-film techniques restrict us to circuits using only resistors (R), capacitors (C), and added semiconductor devices (thin-film inductors are not considered here since their inductance values are too small). The current trend is to realize frequency selective networks (conventionally in LC form) as active RC networks. However, although the circuit described here incorporates such a network, the main selectivity requirement cannot be met by present-day active network techniques. The solution is found in the use of time-varying RC networks, i.e., by combining passive RC thin-film phase-shift networks with miniature transistors, used as electronic switches, in the form of so-called quadrature modulation circuits. The phase-shift networks, which in principle can be passive thin-film RC circuits, are in practice more easily realized as combinations of much simpler RC circuits with buffer amplifiers.     

A broad-band lumped element analytic model incorporating skin effect and substrate loss for inductors and inductor like components for silicon technology performance assessment and RFIC design

We present a broad-band lumped element planar inductor model that is suitable for RFIC design in silicon technologies. We provide extensions of the modeling methodology to similar components such as differential inductors, baluns, and solenoid inductors. The analytic computation of the physics-based model components, incorporating both metal skin effect and substrate loss, is described. The model is validated using measured data from over 200 inductors made with five different silicon back-end process technologies. The physics-based implementation of the model allows its use for determining the optimum process technology characteristics for specific radio frequency integrated circuit (RFIC) designs. The analytical based implementation with lumped elements enables effective integration into a robust CAD system for efficient design of RFIC circuits.