The split-cylinder resonator method was adapted to measure the microwave properties (dielectric permittivity and loss tangent) of thin ferroelectric films on a dielectric substrate. The mathematical model for calculating the resonance frequency of the split-cylinder resonator was adjusted for the “ferroelectric film—substrate” structure. An approach for correcting the gap effect based on calibrating with a single-layer dielectric was introduced and used to study two-layer dielectrics. The prototype of a split-cylinder resonator designed to measure single-layer dielectric plates at a frequency of 10 GHz was presented. The resonator calibration was performed using dielectric PTFE samples and fused silica, and an example of the correction function was suggested. The measurement error was estimated, and recommendations on the acceptable parameter range for the material under investigation were provided. The method was demonstrated to measure the microwave properties of a ferroelectric film on a fused silica substrate.

The effects of ultraviolet (UV) irradiation on the relaxation processes in ${\text{Ba}}_{0.3}{\text{Sr}}_{0.7}{\text{TiO}}_3$ thin film capacitors were experimentally investigated in a range of wavelengths $\lambda =\left(310–400\right)\text{nm}$ . It was observed that irradiation with a specific wavelength reduces the time of slow capacitance relaxation up to three orders of magnitude in comparison with relaxation time in the “dark” regime. It was also observed that at a certain wavelength of UV irradiation there was a maximum in the leakage current of the capacitors. This wavelength corresponded exactly with a minimum in the relaxation time of the capacitance. It was shown that the decrease in the ferroelectric film thickness resulted in a shift in $\tau \left(\lambda \right)\text{minima}$ and $\text{I}\left(\lambda \right)\text{maxima}$ towards the shorter wavelengths. Phenomena observed are analyzed using Bouguer’s law.

We have studied the response speed characteristics of capacitor structures based on thin Ba0.3Sr0.7TiO3(BSTO) films with metal-ferroelectric contacts of various types formed under different...

Thin films of BaSn_xTi_1-xO₃ composition (Sn/Ti ≈50/50) are grown in-situ by RF magnetron deposition onto Pt/Ti/Al₂O₃ substrate. Structural and dielectric properties are optimized by changing substrate temperature. Best thin-film samples have shown a high tunability (about 3.5) and low dielectric losses attractive for microwave electronics.

The advanced design of a millimeter-wave quasi-optical beamforming device (QOBD) based on the ferroelectric ceramic was elaborated and considered. Among the advantages of the proposed design are simplicity and cost-effectiveness in contrast to conventional analog and digital beamforming devices based on array antennas. The use of ferroelectric ceramic in the QOBD design allows operating in a wide frequency range up to 100 GHz. The advanced topology of discrete radiotransparent electrodes to provide a realization of different beamforming functions such as beam focusing and beam scanning was considered. The prototype of the proposed QOBD was designed to operate at 60 GHz. The measured radiation pattern of the QOBD prototype is in good agreement with the simulated one. Measurements demonstrate decreasing of beamwidth of the primary antenna radiation pattern by the lens prototype operating in the beam focusing regime.