THICK-FILM FABRICATION OF FERROELECTRIC PHASE-SHIFTER MATERIALS

Various composites of BSTO combined with other nonelectrically active oxide ceramics have been formulated. In general, the composites have a djustable electronic properties which can be tailored far use in phase d array antennas and other phase shifting devices. The dielectric cons tant and the loss tangents have been reduced to enhance the overall im pedance matching and thereby lowering the insertion loss of the device . In addition, the overall tunability, the change in the dielectric co nstant with applied voltage, is maintained al a sufficiently high leve l. The thickness limitation of the bulk materials is around 3-4 mils w hich can be used up to approximately 15 GHz. In order to increase the operating frequencies of the phase shifters, thick films were fabricat ed using non-aqueous tape-casting The tapes were electrically characte rized and compared to bulk ceramics. Also, laminated stacks of high di electric constant and low dielectric constant alternating layers were fabricated.