Electric‐Field‐Controlled Permittivity Ferroelectric Composition for Microwave LTCC Modules

Abstract

A low‐temperature cofired ferroelectric ceramic composition for electrically tunable radio frequency devices is introduced. A sintering temperature of 950°C for BaSrTiO 3 –MgO was obtained following the combined addition of B 2 O 3 and Li 2 CO 3 . The effects of these sintering aids on densification, microstructure, and ferroelectric properties were investigated. The permittivity and dissipation factor values were 234 and 0.0010, respectively, measured at 286.3 K, 1 kHz. The electrically tunable ferroelectric structure for microwave measurement was fabricated throughout the tape‐casting process. Measured permittivity was 130 at 26 GHz and tunability >15% (4 V/μm).