The Microwave Properties of Ag(Ta_(0.8)Nb_(0.2))0_3 Thick Film InterdigitalCapacitors on Alumina Substrates

摘要

In this paper, we will introduce the microwave properties of Ag(Ta_(0.8)Nb_(0.2))0_3 thick film planar type interdigital capacitors fabricated on alumina substrates. The tailored paraelectric state of Ag(Ta,Nb)0_3 allows the material to be regarded as a part of the family of microwave materials. As thick films formed in our experiment, Ag(Ta,Nb)0_3 exhibited extremely low dielectric loss with relatively high dielectric permittivity. This low dielectric loss is a very important issue for microwave applications. Therefore, we investigated the microwave properties of Ag(Ta_(0,8)Nb_(0.2))0_3 thick film planar type interdigital capacitors. Ag(Ta_(0.8)Nb_(0.2))0_3 thick films were prepared by a screen-printing method on alumina substrates and were sintered at 1140 °C for 2 hrs. The XRD analysis results showed that the Ag(Ta_(0.8)Nb_(0.2))0_3 thick film has the perovskite structure. The frequency dependent dielectric permittivity showed that these Ag(Ta_(0.8)Nb_(0.2)0_3 thick film planar type interdigital capacitors have very weak frequency dispersions with low loss tangents in the microwave range.