Do we really need ferroelectrics in paraelectric phase only in electrically controlled microwave devices?

Low Cost Interdigital BST Varactors for Tunable Microwave Applications

“…By a similar method, the capacitance tunability is ∼21 %. This is at the lower end of the range of values reported in the literature [13], which range from 7 to 75 %. However, by reducing the device dimensions and increasing the bias field, it should be possible to produce devices with competitive performance well into the microwave frequency range.…”

Ferroelectrics Study at Microwaves

“…Main lattice dynamics parameters of studied ferroelectrics are shown in Table 2. Gevorgian & Kollberg, 2001) are drawn with the use of electrodes. For instance, the opposite-electrodes method is employed to study the system Pt/BST/Pt (Banieki et al, 1998).…”

“…Dielectric properties of materials are observed in their interaction with electromagnetic field. Fundamental ability of dielectric materials to increase stored charge of the capacitor was used for years and still used to measure permittivity and loss at relatively low frequencies, up to about 1 MHz (Gevorgian & Kollberg, 2001). At microwaves studied material is usually placed inside transmission line, such as coaxial or rectangular waveguide, or resonant cavity and its influence onto wave propagation conditions is used to estimate specimen's properties.…”

Observation of high dielectric constant of Bi-Nb-O_x thin-film capacitors fabricated by chemical solution deposition process

“…The highdielectric-constant perovskite oxides BaTiO 3 and Ba 1Àx Sr x TiO 3 have thus far been used for MLCCs. However, these materials are often characterized by size effects, high dielectric losses, and high crystallization temperatures (>900°C); consequently, the downsizing and functional improvement of devices are difficult [3,4,5,6,7,8,9,10,11]. Therefore, the development of new materials with high dielectric constants, low dielectric losses, and low leak currents is required.…”