CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

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

Spartak Gevorgian (Institutionen för mikroelektronik och nanovetenskap) ; Erik L. Kollberg (Institutionen för mikroelektronik)
IEEE transactions on microwave theory and techniques (0018-9480). Vol. 49 (2001), 11, p. 2117 - 2124.
[Artikel, refereegranskad vetenskaplig]

Typical paraelectric materials (e.g., SrTiO3, KTaO3, BaxSr1-xTiO3, x<0.5) and electrically tunable microwave devices based on these materials are briefly reviewed. The analysis shows that in spite of the recent year's extensive efforts, no considerable improvement in the microwave losses in thin paraelectric films has been achieved. Thin films, regardless of fabrication method and substrate type, have much lower dielectric permittivity than bulk single crystals, and the loss tangent at microwave frequencies (f>10 GHz) is of the order of 0.01 (at zero dc-bias field) at room temperature. Nevertheless, quite promising component and subsystem level devices are successfully demonstrated. Use of ceramic (bulk and thick film) ferroelectrics in tunable microwave devices, currently considered for industrial applications, offer cost reduction. In this paper, explicitly for the first time, we consider possibilities and benefits of using ferroelectrics in polar phase in electrically controllable microwave devices. Examples of using ferroelectrics in polar state (e.g., Na0.5K0.5NbO3, SrTiO3 in antiferroelectric phase) in electrically tunable devices are reported

Nyckelord: Ferroelectric, microwave

Denna post skapades 2015-02-09.
CPL Pubid: 212341


Institutioner (Chalmers)

Institutionen för mikroelektronik och nanovetenskap (1900-2003)
Institutionen för mikroelektronik (1995-2003)


Elektroteknik och elektronik

Chalmers infrastruktur