Abstract
Use of ferroelectric materials to improve antenna performance is an area of active research.Applying an electric field across a ferroelectric used as the dielectric in an antenna enablestuning the antenna performance. Ferroelectrics also have coupled electro-mechanicalbehavior due to which they are sensitive to mechanical strains and fluctuations in ambienttemperature. Use of ferroelectrics in antenna structures, especially those subject tomechanical and thermal loads, requires knowledge of the phenomenological relationshipbetween the ferroelectric properties of interest (especially the dielectric permittivity) andthe external physical variables, namely electric field(s), mechanical strains andtemperature. To this end, a phenomenological model of ferroelectric materials based on theDevonshire thermodynamic theory is presented. This model is then used to obtain arelationship expressing the dependence of the dielectric permittivity on the mechanicalstrain, applied electric field and ambient temperature. The relationship is compared againstpublished experimental data and other models in the literature. A model relating theferroelectric loss tangent to the applied electric field and temperature is also discussed.Subsequently, relationships expressing the dependences of the antenna operatingfrequency and radiation efficiency on those external physical quantities are described.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call