Dodecahedron lattice of rattling phenomenon, and microwave dielectric properties of yttrium aluminum garnet ceramics and its application verification for Wifi6E/7 patch and 6G resonant antennas
Huan Liu, Yu Jiang, Xueqing Yu, Minmin Mao, Bing Liu, Zhilun Lu, Hadi Barzegar Bafrooei, Shuang He, Yingjie Ren, Ehsan Taheri‐Nassaj, Kaixin Song
Abstract
In garnet phase ceramics Y 2.9 M 0.1 Al 4.9 Si 0.1 O 12 (M = Mg 2+ , Co 2+ , Zn 2+ , Mn 2+ , Ca 2+ , Sr 2+ , Ba 2+ ), rattling effects occur when M = Mg 2+ , Co 2+ , Zn 2+ , Mn 2+ ions with smaller ionic radius (<1Å) occupy the dodecahedron lattice lattices. This results in an abnormally high dielectric constant, in contrast to the larger ionic radius (>1 Å) of M = Ca 2+ , Sr 2+ and Ba 2+ , which deviate from the theoretical values calculated using the Clausius-Mosotti formula according to each ion’s polarizability. The optimal microwave dielectric properties for Y 2.9 Mg 0.1 Al 4.9 Si 0.1 O 12 was obtained by sintering at 1575 °C for 5 h ( Q × f = 51,382 GHz, ε r = 9.74, and τ f = −30.12 ppm/°C). Additionally, a thermal stable Y 2.9 Mg 0.1 Al 4.9 Si 0.1 O 12 -6 wt%TiO 2 composite ceramic was developed. Based on this composite, a Wifi6E/7 patch antenna operating at 6.3 GHz and a millimeter-wave resonant antenna functioning at 27.1 GHz were designed and validated. This indicates the potential application prospects of garnet ceramics in 5G/6G radio communication technologies.