Quasi-TEM characteristic impedance of micromachined CMOS coplanar waveguides

Author

Ozgur, Mehmet ; Milanov, V. ; Zincke, Christian ; Gaitan, Michael ; Zaghloul, Mona E.

Author_Institution

Dept. of Electr. Eng. & Comput. Sci., George Washington Univ., Washington, DC, USA

Volume

48

Issue

5

fYear

2000

fDate

5/1/2000 12:00:00 AM

Firstpage

852

Lastpage

854

Abstract

Micromachined coplanar waveguides (CPW´s) fabricated in CMOS technology consist of glass-encapsulated metal conductor strips, fully suspended by selective etching of the silicon substrate. The minimum amount of etching necessary for proper operation of the micromachined waveguides is determined by using an isolation criterion. In this paper, the quasi-TEM characteristic impedance of a CPW is derived, including the finite conductor thickness and the thicknesses of surrounding dielectric layers. The employed analytical approach is based on conformal mapping and the partial capacitance technique. The losses both in conductor and dielectric layers are neglected. The analytical results and proposed approximations are verified by integral-equation computation and by measurement of various sample structures

Keywords

CMOS integrated circuits; capacitance; coplanar waveguides; electric impedance; etching; integral equations; micromachining; silicon; waveguide theory; Al-SiO₂-Si; CMOS coplanar waveguides; Si; Si substrate; conformal mapping; dielectric layer thickness; finite conductor thickness; glass-encapsulated metal conductor strips; integral-equation computation; isolation criterion; micromachined CMOS CPW; partial capacitance technique; quasi-TEM characteristic impedance; selective etching; CMOS technology; Conductors; Coplanar waveguides; Dielectric losses; Dielectric substrates; Etching; Impedance; Isolation technology; Silicon; Strips;

fLanguage

English

Journal_Title

Microwave Theory and Techniques, IEEE Transactions on

Publisher

ieee

ISSN

0018-9480

Type

jour

DOI

10.1109/22.841883

Filename

841883