Correlation between material properties of ferroelectric thin films and design parameters for microwave device applications: Modeling examples and experimental verification
Fa. Miranda et al., Correlation between material properties of ferroelectric thin films and design parameters for microwave device applications: Modeling examples and experimental verification, INTEGR FERR, 24(1-4), 1999, pp. 195-214
The application of thin ferroelectric films for frequency and phase agile c
omponents is the topic of interest of many research groups worldwide. Conse
quently, proof-of-concepts (POC) of different tunable microwave components
using either (HTS, metal)/ferroelectric thin film/dielectric heterostructur
es or (thick, thin) film "flip-chip" technology have been reported. Either
as ferroelectric thin film characterization tools or from the point of view
of circuit implementation approach, both configurations have their respect
ive advantages and limitations. However, we believe that because of the pro
gress made so far using the heterostructure (i.e., multilayer) approach, an
d due to its intrinsic features such as planar configuration and monolithic
integration, a study on the correlation of circuit geometry aspects and fe
rroelectric material properties could accelerate the insertion of this tech
nology into working systems. In this paper, we will discuss our study perfo
rmed on circuits based on microstrip lines at frequencies above 10 GHz, whe
re the multilayer configuration offers greater ease of insertion due to cir
cuit's size reduction. Modeled results of relevant circuit parameters such
as the characteristic impedance, effective dielectric constant, and attenua
tion as a function of ferroelectric film's dielectric constant, tan delta,
and thickness, will be presented for SrTiO3 and BaxSr1-xTiO3 ferroelectric
films. A comparison between the modeled and experimental data for some of t
hese parameters will be presented.