Broadband Determination of Microwave Permittivity and Loss in Tunable Dielectric Thin Film Materials

Published

October 1, 2000

Author(s)

James Booth, Leila R. Vale, Ronald H. Ono

Abstract

We demonstrate a new method for determining the frequency-dependent dielectric properties of thin-film materials at microwave frequencies using coplanar waveguide (CPW) transmission line measurements. The technique makes use of the complex propagation constant determined from multiline thru-reflect-line (TRL) calibrations for CPW transmission lines to determine the distributed capacitance and conductance per unit length. By analyzing data from CPW transmission lines of different geometries, we are able to determine the complex permittivity of the dielectric thin film under study as a function of frequency from 1 to 40 GHz. By performing these measurements under an applied bias voltage, we are able in addition to determine the tuning and figure of merit that are of interest for voltage-tunable dielectric materials over the frequency range 1 to 26.5 GHz. We demonstrate this technique with measurements of the permittivity, loss tangent, tuning, and figure of merit for a 0.4 5m film of Ba_0.5TiO₁ at room temperature.

Proceedings Title

Proc., Mat. Res. Soc. Symp.: Matls Issues for Tunable RF & Micro. Dev.

Volume

603

Conference Dates

November 30-December 2, 2000

Conference Location

Boston, MA, USA

Pub Type

Conferences

Keywords

coplanar waveguide, dielectric thin, microwave, tunalbe materials

Citation

Booth, J. , Vale, L. and Ono, R. (2000), Broadband Determination of Microwave Permittivity and Loss in Tunable Dielectric Thin Film Materials, Proc., Mat. Res. Soc. Symp.: Matls Issues for Tunable RF & Micro. Dev., Boston, MA, USA (Accessed April 19, 2025)