Layout Synthesis Algorithm of Embedded Passive Components for RF and EMC Reliable System Design Grit Sommer. Wemer John. Herbert Reichl Fraiinhofer 1Z.M Gustav-Meyer-Allee 25. 13355 Berlin
[email protected]. phone: 749 (0)39 46403 149 Abstract The integration of passive components onto a module platform offers great potential for minianuization of RF and microwave systems. Development of component desiLm with respect to electrical requirements is one of the challenges in RF system design. This paper first time introduces layout synthesis algorithm for embedded passive components like capacitor. resistor and inductor. For required electrical parameter of embedded passives (main values) including RF characteristic (resonant kequency. quality factor. 3dB cutoff frequency) the optimized component layout will be generated. For electrical simulation respective s-parameter and equivalent circuit model will be derived. This synthesis procediue is a break through for modem RF system design. The synthesis algorithm is imiversal and can be applied easily for various design types of embedded inductors. capacitors and resistors. The method will be demonstrated using HDI organic square loop inductors as a specific example. Index Terms - layout synthesis, RF design. HDI organic. mdti-layer. embedded passives, embedded inductors, embedded capacitor. embedded resistor. library modeling. compact model. parameterized model, optimization Introduction Today’s fast-paced, wireless marketplace requires a continiioiis offering of products with higher performance in a smaller package at lower cost. The high integration potential and moderate cost of HDI (High-Density Interconnect) organic substrates makes it an attractive platform for the development of RF applications [I]. In typical wireless applications the ratio of passive components to ICs is very high - 4O:l or highcr. depending on the product and manufacturer [3]. The ability to embed passives in the substrate is therefore seen as an attractive way to drive miniahuization and cost reduction. In order to do this. the designer mist be able to confidently predict the electrical performance of these embedded components in a variety of configurations. This can be done one component at a time using elcctromagnetic (EM) simulation. or by selecting Gom a predefined set of components that have already been characterized. or a combination of the two techniques. Modem design techniques use parameterized electrical compact model libraries [3 I. Here the compact model relate the physical layout of the device to the electrical performance. This approach is used extcnsively in IC desi= because it allows for rapid development with specified accuracy. Applying parameterized compact model. the user needs to define values for design parameter. The respective RF characteristic will be calculated. Normally. the problem works
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out in reversc form however. Starting point are the requests with respect to tlic electrical RF characteristics, for these a optimized componciit design needs to be developed. Applying the standard par;inictciized model. the design data must be varied by hand so long until the defined electrical values are reached. Bcsidc the clcctrical criteria usually there exist restrictions with ivqcct to components size (form factor) and consequently costs. A d e s i g 0ptimi7iition considering all requirements by hand works out vciy ilifticiilt and can be managed only with exact knowlcdgc :~hmit thc dependencies of the different parameters (c:l~cn-Lii,)wledge). To improve the l
