Tunability Behavior of (Ba, Ca)(Zr, Ti)O Ceramic Capacitors Powered by Thermally Induced Phase Transitions With Applications to Nonlinear Transmission Lines

Abstract

Ferroelectric ceramics with low loss dielectric, high permittivity, and nonlinear behavior are essential in capacitive nonlinear transmission lines (NLTLs) for radio frequency (RF) generation. NLTLs have the potential to generate soliton waves for high-power microwave (HPM) applications in mobile defense platforms and satellite communications. In this work, we synthesize, characterize, and investigate the nonlinear behavior of (Ba,Ca)(Zr,Ti)O3 ceramics system to be applied as nonlinear elements in capacitive NLTLs. The ceramics were structurally and microstructural characterized. Anomalies in dielectric and pyroelectric curves access the temperatures of phase transitions. The permittivity tunability was studied as a function of electric field and frequency in temperatures near phase transitions. The phase transitions of materials are identified by temperature where the permittivity and percentage of nonlinear tunability factor (NTF) are higher, which are required to produce RF on NLTLs.