Material issues for electrically tunable microwave devices
* SPEAKERS
Name
Affiliation
E-mail
Baeho Park
Konkuk Univ.
* HOST(Applicant)
Name
Affiliation
E-mail
-
* DATE / TIME
2003-05-05, 3:00 pm
* PLACE
Bldg 3, Room#103, POSTECH
* ABSTRACT
Tunable microwave devices utilize materials or structures whose phase velocities or resonant frequencies can be tuned by electrical, magnetic, or mechanical methods. Nonlinear dielectric material, such as (Ba,Sr)TiO3 (BST), is a good candidate material for an electrically tunable microwave device since its large tunability (change in dielectric permittivity under an external electric field) as well as low dielectric loss.
However, it is well known that a BST thin film shows smaller tunability and higher dielectric loss than those of a bulk BST. Therefore, it is very important to find origins for the anomalous dielectric properties of a BST thin film and to fabricate a BST thin film with large tunability and low dielectric loss. It is also very significant to decrease the temperature coefficient of capacitance (TCC) of a nonlinear dielectric thin film in order to use an electrically tunable microwave device in a wide temperature range. In this talk, I'll show our efforts to increase tunability and to decrease dielectric loss and TCC of nonlinear dielectric thin films.
