Microwave study of tunable planar capacitors using mn-doped ba0.6sr0.4tio3 ceramics

• Published in: IEEE transactions on ultrasonics, ferroelectrics, and frequency control Vol. 56; no. 11; pp. 2363 - 2369
• Main Authors: Laur, V., Costes, R., Houndonougbo, F., Madrangeas, V., Cros, D., Pate, M., Ganne, J.-P.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01-11-2009; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Binary search trees; Capacitors; Ceramics; Ceramics - chemistry; Circuit properties; Dielectric losses; Dielectric measurements; Electric Capacitance; Electric, optical and optoelectronic circuits; Electronics; Electronics - instrumentation; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Fingers; Impedance; Materials Testing; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Permittivity measurement; Temperature; Voltage; Electrotechnical ceramics; GHz range; Coplanar technology; Capacitive transducer; Microwave; Barium titanates; Silicon oxides; Manganese addition; Strontium titanates; Capacitance; Capacitor; Bilayers; Planar technology
• ISSN: 0885-3010; 1525-8955
• DOI: 10.1109/TUFFC.2009.1324

This paper deals with the microwave study of coplanar tunable capacitors using Mn-doped Ba 0.6 Sr 0.4 TiO 3 ceramics. These ceramics are developed to improve performance at microwave frequencies (i.e., compromise between tuning capabilities and insertion losses). Interdigitated capacitors were first fabricated on thick Mn-doped BST ceramics. The capacitors showed reduced tuning factor because of a parasitic capacitance between the contact pads. The use of Mn-doped BST/ SiO 2 bilayers led to a significant enhancement of the capacitor performance (57% of agility under 200 V at 1 GHz).