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Über dieses Buch

This book describes the basic principles of designing and modelling inductors, MIM capacitors and coplanar waveguides at frequencies of several tens of GHz. The author explains the design and modelling of key, passive elements, such as capacitors, inductors and transmission lines that enable high frequency MEMS operating at frequencies in the orders of tens of GHz.

Inhaltsverzeichnis

Frontmatter

Chapter 1. RF MEMS Process of Fraunhofer ISiT

Abstract
In technologies used for high frequencies, high resistivity silicon is usually employed as the substrate material. Its high resistivity reduces the microwave losses. In order to prevent DC-currents and bias-dependent leakage from flowing into the substrate, the silicon surface is typically covered with 500 to 2,000 nm thick layer of oxide. The substrate in the ISiT technology is composed of a 508 \(\upmu \)m thick high-resistivity silicon layer with a resistivity larger than 3,000 \(\varOmega \times \) cm, and a 2,000 nm thermally fabricated silicon oxide layer on top. The available layers in the technology as shown in Fig. 1.1.
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Chapter 2. Designing Inductors

Abstract
Spiral inductors are commonly used in radio-frequency integrated circuits (RFICs) to act as series or shunt elements in the matching, tank or choke circuits. The quality factor (Q) is among the most important parameters in order to evaluate an inductor’s performance. Unfortunately, quality factor and frequency limitations limit RF front-end circuitry to a large number of discrete passive components and make RF front-end module integration difficult. High-quality-factor inductor design and fabrication remains a challenge for applications that depend on passive components performance, e.g. low phase-noise voltage-controlled oscillator (VCO), power amplifier (PA), low noise amplifier (LNA) and double-balanced Gilbert-cell mixers.
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Chapter 3. Modeling the Coplanar Line

Abstract
A coplanar line (waveguide) is composed of a signal track with two return conductors on its two sides. All three are in the same plane.
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Chapter 4. DC-Block Modeling

Abstract
DC-block (which is an MIM capacitor) is another component that is used in the circuits. Here in the following, a DC-block is modeled which may have different combinations of dielectric layers (a single AlN layer, a single SiN layer, or a combination of both, refer to Chap. 1 for explanation of the layers), and different geometrical dimensions (overlap length, center metal width, ground metal width, ...). In the literature there are numerous articles that simply extract the model elements (like ideal capacitor, resistor, inductor, ... which build the equivalent circuit of the MIM-capacitor) from the measured S-parameters of the built capacitors. However none of these approaches calculates the model elements directly from the MIM capacitor’s geometrical characteristics. So what is done here is quite a new approach.
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Chapter 5. Design-Kit Programming

Abstract
In the last chapters different passive elements were modeled or optimized. The best way to use these models and structures is to put them inside a design-kit in ADS. This helps the designers to work fast and efficiently with them.
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Chapter 6. Summary

Abstract
In this essay first it was explained that how a technology introduced by Fraunhofer institute suppresses the losses caused by the inversion channels under the oxide layer of the ISiT substrate. It was shown that this makes it possible to predict the losses of passive elements in this technology by setting the substrate loss to zero in the EM simulations. This in turn assures that the simulated results shown here for the losses are close to reality.
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Backmatter

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