Ferroelectric non-hysteresis actuator for microwave tuneable devices

Low loss and highly tuneable microwave filters controlled by piezoelectric actuator are discussed. Dielectric or metallic parts of device should have the piezo-dirigible air gap between them. The most important for these devices is to use non-hysteresis relaxor ferroelectric ceramics with large electrostriction. Electromechanic way of control has restriction in the speed of operation, and this problem is estimated by the microwave investigation of relaxor ceramics that is used as main actuator material.