Method for Increasing the Electrical Strength of Ferroelectric Planar Capacitors

Introduction. Increasing the electrical strength of planar ferroelectric capacitors is essential for their application in controlled microwave devices. To address this problem, a four-electrode capacitor design is investigated. Analytical calculations and numerical simulations of the electric field distribution are presented for two- and four-electrode structures; a quantitative assessment of controllability for both structures is obtained. In addition to increasing electrical strength, the transition to a four-electrode design affects several related capacitor characteristics. Accordingly, the possibility of suppressing parasitic capacitance modulation by alternating voltage and selecting a substrate material based on thermal and technological criteria is considered. Thus, the presented work provides a comprehensive analysis of methods for improving the characteristics of planar ferroelectric capacitors.
Aim. To investigate a method for increasing the controllability (electrical strength) of planar capacitors and to analyze factors such as capacitance modulation by an alternating field and the selection of a substrate material based on thermal and technological characteristics.
Materials and methods. The capacitor characteristics were numerically simulated using specialized software.
Results. Electrodynamic modeling and analytical calculation of the capacitor structures were performed. The controllability of various planar capacitor structures was quantitatively assessed. Different dielectric substrate materials for ferroelectric capacitors were compared. The effect of microwave signal capacitance modulation was quantitatively analyzed.
Conclusion. It was shown that the four-electrode design can withstand a higher level of control voltage than a conventional two-electrode capacitor and, consequently, provides a greater level of controllability (a 50% increase). When the amplitude of the DC voltage exceeds that of the AC voltage, capacitance modulation decreases. Comparative characteristics of several substrate materials are presented.

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