Ferroelectric Thin Films for Tunable Microwave Applications

Modern wireless communication systems are based on microwave technologies. Ferroelectric devices with the electric field dependent dielectric properties and low dielectric losses at microwave frequencies are very promising. Capacitance tunability nc, defined as the ratio of the capacitance at zero applied bias voltage to the capacitance at some desired applied voltage, is the key functional property of ferroelectric materials. In order to avoid losses arising from the domain wall motion, these materials are mainly used in their paraelectric phase. [1]