Niobate-based microwave dielectrics suitable for third generation mobile phone base stations

Hughes, H.; Iddles, D. M.; Reaney, I. M.
October 2001
Applied Physics Letters;10/29/2001, Vol. 79 Issue 18, p2952
Academic Journal
High unloaded quality factor (Q[sub u]), zero temperature coefficient of resonant frequency (τ[sub f]) and high relative permittivity (ε[sub r]) microwave dielectric ceramics have been fabricated based on BaZn[sub 1/3]Nb[sub 2/3]O[sub 3]. Properties have been optimized for the composition, 0.9Ba([Zn[sub 0.60]Co[sub 0.40]][sub 1/3]Nb[sub 2/3])O[sub 3]–0.1Ba(Ga[sub 0.5]Ta[sub 0.5])O[sub 3] for which Q[sub u]=32 000 @ 3.05 GHz, ε[sub r]=35, and τ[sub f]=0. The new compounds are disordered according to x-ray diffraction (XRD) and may be indexed using a simple perovskite unit cell, a=4.09 Å. Small peaks (e.g., dapprox. 3.01 Å, relative intensity, 4.5) attributed to a barium niobate second phase are also present in XRD patterns. These ceramics are suitable in terms of cost and performance for base stations supporting third generation architecture. © 2001 American Institute of Physics.


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