Performance Analysis of RF Spiral Inductor with Gradually Changed Metal Width and Space

To decrease the metal losses of RF spiral inductor,a novel layout structure with gradually reduced metal line width and space from outside to inside is presented. This gradual changed inductor has less eddy-current effect than the conventional inductor of fixed metal width and space. So the series resistance can be reduced and the quality （Q） factor of the inductor relating to metal losses is increased. The obtained experimental results corroborate the validity of the proposed method. For a 6nH inductor on high-resistivity silicon at 2.46GHz,Q factor of 14.25 is 11.3% higher than the conventional inductor with the same layout size. This inductor can be integrated with radio frequency integrated circuits to gain better performance in RF front end of a wireless communication system.

A 2.4GHz CMOS Quadrature Voltage-Controlled Oscillator Based on Symmetrical Spiral Inductors and Differential Diodes

A voltage controlled oscillator (VCO) which can generate 2 4GHz quadrature local oscillating (LO) signals is reported.It combines a LC VCO,realized by on chip symmetrical spiral inductors and differential diodes,and a two stage ring VCO.The principle of this VCO is demonstrated and further the phase noise is discussed in detail.The fabrication of prototype is demonstrated using 0 25μm single poly five metal N well salicide CMOS digital process.The reports show that the novel VCO is can generate quadrature LO signals with a tuning range of more than 300MHz as well as the phase noise--104 33dBc/Hz at 600KHz offset at 2 41GHz (when measuring only one port of differential outputs).In addition,this VCO can work in low power supply voltage and dissipate low power,thus it can be used in many integrated transceivers.

MEMS Inductor Consisting of Suspended Thick Crystalline Silicon Spiral with Copper Surface Coating

A novel MEMS inductor consisting of a planar single crystalline silicon spiral with a copper surface coating as the conductor is presented. Using a silicon-glass anodic bonding and deep etching formation-and-release process,a 40μm-thick silicon spiral is formed, which is suspended on a glass substrate to eliminate substrate loss. The surfaces of the silicon spiral are coated with highly conformal copper by electroless plating to reduce the resis- tive loss in the conductor,with thin nickel film plated on the surface of the copper layer for final surface passivation. The fabricated inductor exhibits a self-resonance frequency higher than 15GHz,with a quality factor of about 40 and an inductance of over 5nil at 11.3GHz. Simulations based on a compact equivalent circuit model of the inductor and parameter extraction using a characteristic-function approach are carried out,and good agreement with measurements is obtained.

Lumped Equivalent Circuit of Planar Spiral Inductor for CMOS RFIC Application

A lumped π-type equivalent circuit of planar spiral inductor for CMOS RFIC application is developed by the domain decomposition method for conformal modules （DDM-CM）. Closed form expressions of lumped parameters for a square spiral inductor on a Si-SiO2 substrate are obtained and verified with the previously published experimental results.

Parameter Extraction for 2-π Equivalent Circuit Model of RF CMOS Spiral Inductors

A novel parameter extraction method with rational functions is presented for the 2-πequivalent circuit model of RF CMOS spiral inductors. The final S-parameters simulated by the circuit model closely match experimental data. The extraction strategy is straightforward and can be easily implemented as a CAD tool to model spiral inductors. The resulting circuit models will be very useful for RF circuit designers.

Fabrication of Meander and Spiral Type Micro Inductors

To obtain microstructure of magnetic devices, the thin film inductors were fabricated by the process such as thin film manufacturing, photolithography and wet etching. The frequency characteristics of these devices are measured at high frequency range. When the inductor sizes of the spiral and the meander type are same, the inductance and the quality factor of the spiral type inductor are larger than those of the meander type inductor, but the driving frequency of the spiral type inductor is lower than that of the meander type inductor.

The coupling effect of air-bridges on broadband spiral inductors in SiC-based MMIC technology

The coupling effect of air-bridges on broadband spiral inductors in SiC-based MMIC technology has been investigated deeply. The fabricated 1-nH spiral inductor on SiC substrate demonstrates a self-resonant frequency of 51.6 GHz, with a peak Q-fact of 12.14 at 22.1 GHz. From the S-parameters measurements, the exponential decay phenomenon is observed for L, Q-factor, and SRF with the air-bridge height decreasing, and an analytic expression is concluded to exactly fit the measured data which can be used to predict the performance of the spiral inductor. All the coefficients in the formula have specific meaning. By means of establishing the lumped model, the parasitic coupling capacitance of the air-bridge has been extracted and presents the exponential decay with the air-bridge heights decreasing which indicates that this capacitor is directly related to the coupling effect of the air-bridge. Through the electromagnetic field distribution simulation, the details of the electric field around the air-bridge have been presented which demonstrate the formation and the variation principles of the coupling effect.

Fabrication and Performance of Novel RF Spiral Inductors on Silicon

This paper discusses fabrication and performance of novel circular spiral inductors on silicon. The substrate materials underneath the inductor coil are removed by wet etching process. In the fabrication process, fine polishing of the photoresist is used to simplify the processes and ensure perfect contact between the seed layer and the top of pillars. Dry etching technique is used to remove the seed layer. The results show that Q-factor of the inductor is greatly improved by removing silicon underneath the inductor coil. The spiral inductor with line width of 50 μm has a peak Q-factor of 10 for the inductance of 2.5 nH at frequency of 1 GHz, and the resonance frequency of the inductor is about 8.5 GHz. For the inductor of conductor width 80 μm, the peak Q-factor increases to about 17 for inductance of 1.5 nH in the frequency range of 0.05 -3.00 GHz.

Layout Design and Optimization of RF Spiral Inductors on Silicon Substrate

The effects of key geometrical parameters on the performance of integrated spiral inductors are investigated with the 3D electromagnetic simulator HFSS.While varying geometrical parameters such as the number of turns(N),the width of the metal traces(W),the spacing between the traces(S),and the inner diameter(ID),changes in the performance of the inductors are analyzed in detail.The reasons for these changes in performance are presented.Simulation results indicate that the performance of an integrated spiral inductor can be improved by optimizing its layout.Some design rules are summarized.

Simplified Model of a Layer of Interconnects under a Spiral Inductor

An empirical effective medium approximation that provides a homogeneous equivalent for a layer of interconnects un-derneath a spiral inductor is presented. When used as part of a numerical 3D model of the inductor, this approach yields a faster simulation that uses less memory, yet still predicts the quality factor and inductance to within 1%. We expect this technique to find use in the electromagnetic modeling of System-on-Chip.

A Fundamental Approach for Design and Optimization of a Spiral Inductor

This technical paper presents a fundamental approach for design and optimization of a spiral inductor using ASITIC(analysis and simulation of spiral inductors and transformers for ICs)and SpiralCalc(integrated spiral inductor calculator).Both tools are available for research and non-commercial purposes.Inductors are key components esp.for impedance matching and are designed such that they would exhibit a high Q-factor(quality-factor)for the specific inductance and frequency range of operation.A sample value of 5.3 nH is set for this paper for the spiral inductor design using the tools.For optimum Q-factor,an octagonal geometry for spiral inductor is used for ASITIC design,to have a close comparison to that of the SpiralCalc.Design methodologies for the optimization of the spiral inductor parameters such as the inductance and the Q-factor are discussed.Results comparison between the two tools is also presented.Design tradeoffs between inductor parameters are inevitable,and these parameters affect the performance of the inductor esp.at higher frequencies.With this,it is crucial that inductors be designed carefully for their effective frequency range of operation and specific requirements of the intended application.

The Application of FDTD and Micro Genetic Algorithms on the Planar Spiral Inductors

High Q inductors are the important elements for RF circuit design. In this paper, the FDTD method is applied to explain the crowding effect of the spiral inductor , which can never be accurately analyzed by analytical solutions. The experimental results verify the FDTD simulation. The micro genetic algorithms and FDTD are combined to design the high Q of the inductor, the results show the efficiency of this exploration.

A Novel Lateral Solenoidal On-Chip Integrated Inductor Implemented in Conventional Si Process

A new structure of the on- chip integrated inductors im plem ented in conventional Si process is presented as a lateral solenoid.The fabrication process utilizes a conventional Si technology with standard double- layer m etal- lization.S param eters of the inductors based equivalent circuit are investigated and the inductor parameters are cal- culated from the m easured data.Experimental results are presented on an integrated inductors fabricated in a lateral solenoid type utilizing double m etal layers rather than a single metal layer as used in conventional planar spiral de- vices.Inductors with peak Q of 1.3and inductance value of 2 .2 n H are presented,which are com parable to conven- tional planar spiral inductors.

Analysis of substrate eddy effects and distribution effects in silicon-based inductor model

The concepts of substrate eddy influence factor and distribution-effects-occurring frequency are presented. The effects of substrate resistivity and inductor spiral length on the substrate eddy and distribution effects are captured. The substrate eddy influence factors of an inductor （6 turn, 3 060 μm in length） fabricated on low （ 1 Ω. cm） and high resistivity（ 1 000 Ω.cm） silicon substrates are 0. 3 and 0. 04, and the distribution-effects- occurring frequencies are 1.8 GHz and 14. 5 GHz, respectively. The measurement results show that the equivalent circuit model of the inductor on low resistivity silicon must take into consideration substrate eddy effects and distribution effects. However, the circuit model of the inductor on high resistivity silicon cannot take into account the substrate eddy effects and the distribution effects at the frequencies of interest. Its simple model shows agreement with the measurements, and the contrast is within 7%.

基于水性功能油墨的气溶胶喷印工艺的研究及应用

气溶胶喷印水性功能油墨能为微纳柔性电子技术提供更环保的解决方案,但在油墨特性及复杂的打印参数共同作用下,其打印连续性、迹线成形、过度喷涂方面的缺陷亟待解决。基于聚乙烯吡咯烷酮(PVP)水性油墨,通过控制变量法系统地探究了适用于气溶胶喷印的水性油墨黏度(1~10 mPa·s)并优化了喷印工艺,总结出水性油墨黏度与气溶胶喷印的最优参数范围设置规律,并据此进行了水性纳米银油墨的喷印,制备了外径为1.96 mm的平面螺旋电感,表征了其电感及品质因数,测试结果与仿真结果有良好的一致性,其电感在0.024μH左右,可应用于射频识别(RFID)、滤波以及感应元件等领域。该结果为气溶胶喷印水性功能油墨的研究提供了前期的实验支持,有望推动气溶胶喷印在微纳柔性电子技术中的发展。

一种基于物理模型与遗传算法的平面螺旋电感的优化技术

针对 CMOS RF平面螺旋电感的物理模型 ,提出了一种使用遗传算法优化电感设计参数的优化技术 .应用这种技术 ,人们无需再通过等 Q值线来求取 Q值最佳的电感设计方案 ,因为等 Q值线的计算代价很高 ,而且一旦工艺条件改变 ,所有的等 Q值线都要重新计算 ,效率很低 .而这里提出的优化技术在计算时并没有将所有的电感版图设计方案都计算一遍 ,因而计算效率大大提高 .计算结果与相应设计方案的测量参数比较 ,只有约 5 %的计算误差 .计算结果与相同条件下的等 Q值线的最佳设计方案比较 ,这种优化技术总能得出与之基本一致的最佳方案 .事实上 ,由于这种优化技术的灵活性 ,“真正”的最佳设计方案只能由这种优化技术得出 ,而等 Q值线只能得出“相对”

一种新型无芯PCB平面电感器研究

本文主要介绍了在印制板上制作无芯电感的方法 ,分析了其结构和性能 ,并采用数值计算方法建立了平面电感计算模型 ,为设计电感提供了一条切实可行的途径。采用现代化的印制板技术 ,可以精确地控制电感器的绕线宽度、线间距 ,克服了机器绕线一致性差的缺点 ,并使电感从三维向两维发展 。

GaAs MMIC用无源元件的模型

制作了不同结构参数的GaAsMMIC无源元件,包括矩形螺旋电感、MIM电容和薄膜电阻,建立了无源元件的等效电路模型库,采用多项式公式表征无源元件的模型参数和性能参数,便于电路设计的应用.并提取得到MIM电容的单位面积电容值,约为195pF/mm2,NiCr薄膜电阻的方块电阻约为16·1Ω/□.分析结构参数对螺旋电感性能的影响可知,减小线圈面积相关的寄生损耗有助于获得高品质的电感.

XCTD剖面仪螺旋电感固有电容的建模与分析

提出了一种预测XCTD剖面仪的螺线电感固有电容的计算方法,采用最优解析法建立双股螺旋电感线圈的分布电容模型。首先推导出各基本结构单元分布电容的计算公式,计算出实际电感线圈基本结构单元的分布电容,最终对各个参数进行了分析与讨论,得出各参数对分布电容的大小的影响。分析结果可以用来指导电感线圈的设计,减小分布电容已达到提高电感线圈的传输性能。

一种基于二分搜索法的平面螺旋电感的快速优化技术

针对平面螺旋电感的物理模型和Jenei等提出的闭式电感公式 ,提出了一种基于二分搜索法在工艺参数和工作频率确定的条件下快速优化电感版图参数的技术 .实验证明Jenei公式的计算速度比Greenhouse方法提高了大约两个数量级并且能够提供相当的精度 .对Jenei公式进一步数学分析证明在工艺参数和工作频率确定的条件下可以用二分搜索法快速地找出满足电感值和其他约束条件的所有版图参数 ,并从中选出Q值最大的一组 .