RESPONSE-TIME AND POWER HANDLING CAPABILITY OF TUNABLE MICROWAVE DEVICES USING FERROELECTRIC-FILMS

The microwave (MW) performance of tunable stripline resonators with fe rroelectric (SrTiO3 or (Ba, Sr)TiO3) planar capacitors under exposure to high voltage video pulses and MW (10 GHz) signals are studied. The resonator switching times were less than 30 nanoseconds, and these val ues were limited by the measurement apparatus. The dependence of film capacitance and MW loss in ferroelectric films as a function of MW sig nal level, and their variation during the pulse, were measured. The la rge signal MW dielectric constant and loss tangent varied by less than 10% with increasing MW voltage amplitude for MW field strengths up to 1 MV/m in SrTiO3 films, and 0.5 MV/m in (Ba, Sr)TiO3 films.