Microwave Frequency Tuning and Harmonic Generation in Ferroelectric Thin Film Transmission Lines

Published

July 22, 2002

Author(s)

James Booth, Ronald H. Ono, Ichiro Takeuchi, Kao-Shuo Chang

Abstract

We present the results of third harmonic generation measurements in coplanar waveguide transmission lines incorporating thin films of the nonlinear dielectric material Ba_0.3Sr_0.7TiO₃ at a fundamental frequency of 3 GHz. We interpret these results based on a simple model of a distributed voltage-dependent nonlinear capacitance per unit length. We compare the coefficient of the quadratic term in the assumed polynomial expansion of C(Vrf) obtained from the third harmonic generation results with the coefficient of the quadratic term in C(Vdc) obtained by direct measurements of the distributed capacitance at 3 GHz using a dc bias voltage, and obtain excellent agreement for a number of different measurement temperatures in the range 235 K - 295 K. These measurements demonstrate that detrimental high-frequency nonlinear effects can be accurately predicted based on dc-biased measurements, and suggest that ferroelectric thin films can be tuned on timescales that are on the order of nanoseconds.

Citation

Applied Physics Letters

Volume

81

Issue

4

Pub Type

Journals

Keywords

ferroelectric transmission lines, microwave nonlinearity, nonlinear dielectric, voltage-tunable

Citation

Booth, J. , Ono, R. , Takeuchi, I. and Chang, K. (2002), Microwave Frequency Tuning and Harmonic Generation in Ferroelectric Thin Film Transmission Lines, Applied Physics Letters (Accessed July 2, 2025)