Electrostrictive tuneable microwave devices

Electrostriction can be used to control low loss and highly tunable microwave dielectric devices (filters and phase shifters). Dielectric or metallic parts of such a device should have the dirigible air gap between them. For non-hysteresis control these devices use relaxor ferroelectric with large electrostriction. However, electro-mechanic way of control might have a restriction in the speed of operation. This question is estimated by the microwave investigation of relaxor ceramics. Several designs of tunable microwave devices are discussed.