High permittivity and low loss microwave dielectrics suitable for 5G resonators and low temperature co-fired ceramic architecture

Bi-2(Li0.5Ta1.5)O-7 + xBi(2)O(3) (x = 0, 0.01 and 0.02) ceramics were prepared using a solid state reaction method. All compositions were crystallized in a single Bi-2(Li0.5Ta1.5)O-7 phase without secondary peaks in X-ray diffraction patterns. Bi-2(Li0.5Ta1.5)O-7 ceramics were densified at 1025 degrees C with a permittivity (epsilon(r)) of similar to 65.1, Q(f) similar to 15500 GHz (Q similar to microwave quality factor; f similar to resonant frequency; 16 780 GHz when annealed in O-2) and the temperature coefficient of resonant frequency (TCF) was similar to -17.5 ppm degrees C-1. The sintering temperature was lowered to similar to 920 degrees C by the addition of 2 mol% excess Bi2O3 (epsilon(r) similar to 64.1, a Q(f) similar to 11200 GHz/11650 GHz when annealed in O-2 and at a TCF of similar to -19 ppm degrees C-1) with compositions chemically compatible with Ag electrodes. Bi-2(Li0.5Ta1.5)O-7 + xBi2O3 are ideal for application as dielectric resonators in 5G mobile base station technology for which ceramics with 60 < epsilon(r) < 70, high Q(f) and close to zero TCF are commercially unavailable. They may additionally prove to be useful as high er and high Q(f) Bi-2(Li0.5Ta1.5)O-7 Bi-2(Li0.5Ta1.5)O-7 materials in low temperature co-fired ceramic (LTCC) technology.