Conservation of Permittivity and Tunability of Ferroelectrics Over Temperature |
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| Authors: | A. Prudan A. Kozyrev A. Zemtsov V. Osadchy D. Ginley T. Kaydanova |
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| Affiliation: | 1. St. Petersburg Electrotechnical University, 5 Prof. Popov str., St. Petersburg, Russia, 197376;2. National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado, 80401 |
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| Abstract: | The existence of an intersection point of electric field strength dependencies of permittivity of ferroelectrics at different temperatures is theoretically described by Ginzburg-Devonshire (GD) theory and experimentally confirmed by studying (Ba0.3Sr0.7)TiO3 (BSTO) and SrTiO3 (STO) thin film varactors. GD analysis enables one to propose a way to improve the thermal stability of ferroelectric microwave devices. In particular, parameters of a L-band digital (0°/180°) phase-shifter fabricated from thick BSTO film varactors were stabilized in the temperature range T = (210–310) K by application of variable to DC control voltages. |
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| Keywords: | Ferroelectric film permittivity tunability thermal stabilization phase shifter |
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