Characterization of the Ba(1–x)Sr(x)(Zr0.2Ti0.8)O3 Ceramic as a Nonlinear Capacitor for LC-Based Nonlinear Transmission Lines

Ferroelectric ceramics can be used as nonlinear capacitors in nonlinear transmission lines (NLTLs) to generate radio frequency with applications in defense systems and pulsed radars. Their primary feature is their nonlinear behavior, which is the variation in capacitance with temperature and electric field. One crucial ceramic material for these uses is barium titanate (BT). The ceramic paraelectric phase, however, is above the Curie temperature of $120~^{\circ }$ C in its pure form. We synthesized and studied the ${\mathrm {Ba}}_{(1 -x)}$ ${\mathrm {Sr}}_{(x)}$ (Zr_0.2Ti_0.8)O₃ ceramic as a nonlinear element by downshifting the paraelectric to ferroelectric phase transition close to ambient temperature to enhance the nonlinear characteristics. By varying the frequency and applied electric field, we examined the capacitance behavior of this material. Additionally, we discovered that this ceramic composite’s paraelectric phase transition occurred at a concentration of ${x} =0.5$ % strontium. To illustrate the RF generation, we constructed and tested a nonlinear LC circuit employing ten ceramic samples that contained 0.5% strontium as nonlinear capacitors. Finally, we estimated the RF frequency generated to be 5.4 MHz by deriving expressions for the propagating solitary-wave solution, which agrees with the experimentally determined value.