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Quasi-TEM Characteristic Impedance of Micromachined CMOS Coplanar Waveguides



Mehmet Ozgur, V. Milanovic, C. A. Zincke, Michael Gaitan, Mona E. Zaghloul


Micromachined coplanar waveguides fabricated in CMOS technology consist of glass-encapsulated finite-thickness metal conductor strips, fully suspended by selective etching of the silicon substrate. Determination of the quasi-TEM mode characteristic impedance requires knowledge of the quasi-static capcitance of the complete structure, and the quasi-static capacitance of the equivalent air-line structure. In this paper, analytical results are derived for such structures based on conformal mapping transformations and partial capacitance approach. The analytical results and proposed approximations are verified by a finite-difference computational approach and by measurement results on various sample structures. The results are useful for solving general capacitance problems for finite-thickness planar transmission lines with multi-layer dielectric.
IEEE Transactions on Microwave Theory and Techniques


Silicon micromachining, coplanar waveguide, quasi-static, quasi-TEM mode, characteristic impedance, effective permittivity


Ozgur, M. , Milanovic, V. , Zincke, C. , Gaitan, M. and Zaghloul, M. (2000), Quasi-TEM Characteristic Impedance of Micromachined CMOS Coplanar Waveguides, IEEE Transactions on Microwave Theory and Techniques (Accessed July 17, 2024)


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Created May 4, 2000, Updated October 12, 2021