Nonlinear Properties of Thin Ferroelectric Film-Based Capacitors at Elevated Microwave Power

A key interest in high power high frequency microwave devices is their performance at high power levels. The authors discuss two mechanisms determining the capacitance variations of a thin ferroelectric film-based nonlinear capacitor under elevated microwave power levels analytically and experimentally studied over wide frequency range. The mechanisms are the dielectric nonlinearity under the microwave electric field and ferroelectric film heating due to microwave energy dissipation. It is shown that for thin ferroelectric film parallel plate capacitive structures up to millimeter-wave frequency range, the electric field effect is the dominant mechanism in the capacitance variations, and for limitations on power handling.