Thin-film ferroelectric microwave devices

• Published in: Superconductor science & technology Vol. 11; no. 11; pp. 1323 - 1334
• Main Authors: Lancaster, M J, Powell, J, Porch, A
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.11.1998; Institute of Physics
• Subjects: Applied sciences; Circuit properties; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Thermal characteristic; Ternary compound; Ferroelectric device; Microwave device; Q factor; Disk resonator; Coplanar line; Microwave filter; Microstrip; Strontium Titanates; Thin film; Quaternary compound; Non linear device; Barium Titanates; Permittivity
• ISSN: 0953-2048; 1361-6668
• DOI: 10.1088/0953-2048/11/11/021

When an electric field is applied to a ferroelectric material, the microwave permittivity undergoes a substantial change. This change in permittivity can be utilized in microwave devices to produce frequency-agile functions. This paper is a comprehensive review of the work on ferroelectric materials; this includes models of the ferroelectric permittivity and loss tangent, as well as methods of measurement of these properties. New measurements are presented on thin-film strontium titanate and single-crystal strontium barium titanate substrates. These results are compared with the model. A brief discussion is given of the applications of ferroelectric material in microwave devices.