Microwave properties of BST thin film interdigital capacitors on low cost alumina substrates

Jayesh Nath, Michael B. Steer, Dipankar Ghosh, Jon Paul Maria, Angus Kingon, Gregory T. Stauf

Research output: Chapter in Book/Report/Conference proceedingConference contribution

20 Scopus citations

Abstract

Barium Strontium Titanate (BST) thin films have a permittivity that is dependent on applied electric-field. As electronically tunable lumped capacitors they can be used as microwave varactors in phase shifters, tunable filters, and delay lines. Generally BST films are deposited on single crystalline substrates. This paper reports on the microwave properties of BST films deposited on low cost alumina substrates by means of metal organic chemical vapour deposition using inexpensive copper metallization. Interdigital capacitors were fabricated yielding capacitors in the sub-picofarad range and tunable by voltages up to 120 V. Low frequency intrinsic Q's of over 100 were obtained. This reduced to external Q's of 17 at 26GHz for 0.5 μm electrodes. The maximum dielectric tunability was found to be about 1.64:1 (40%) for an applied field of 300 kV/ cm at a bias of 120 V.

Original languageEnglish (US)
Title of host publicationConference Proceedings- 34th European Microwave Conference
Pages1497-1500
Number of pages4
StatePublished - Dec 1 2004
EventConference Proceedings- 34th European Microwave Conference - London, United Kingdom
Duration: Oct 12 2004Oct 14 2004

Publication series

NameConference Proceedings- European Microwave Conference
Volume3

Other

OtherConference Proceedings- 34th European Microwave Conference
CountryUnited Kingdom
CityLondon
Period10/12/0410/14/04

All Science Journal Classification (ASJC) codes

  • Engineering(all)

Fingerprint Dive into the research topics of 'Microwave properties of BST thin film interdigital capacitors on low cost alumina substrates'. Together they form a unique fingerprint.

  • Cite this

    Nath, J., Steer, M. B., Ghosh, D., Maria, J. P., Kingon, A., & Stauf, G. T. (2004). Microwave properties of BST thin film interdigital capacitors on low cost alumina substrates. In Conference Proceedings- 34th European Microwave Conference (pp. 1497-1500). (Conference Proceedings- European Microwave Conference; Vol. 3).