The simulation for a high-efficiency millimeter wave microstrip antenna by low dielectric loss and wide temperature stable lithium-based microwave dielectric ceramics for LTCC applications

As a common flux agent, B₂O₃–CuO was introduced into Li₂TiO₃ system to reduce the sintering temperature for the requirements of LTCC applications. The optimal mass ratio of CuO to B₂O₃ was innovatively explored. When the mass ratio of CuO to B₂O₃ increased to 1.2:1.0, excellent microwave dielectric properties were obtained in LTMF<ZN_0.892+CB_1.2 ceramic of ε_r = 13.23, Q × f = 62,749 GHz, τ_f = -2.48 ppm/°C and the sintering temperature was reduced from 1300 to 930 °C. In a wide temperature range, the sample still maintain high temperature stability of |τ_f| < 5 ppm/°C (-40–120 °C). Based on the LTMF<ZN_0.892+CB_1.2 substrate, a millimeter wave microstrip antenna resonated at 30.12 GHz was designed with a considerably high radiation efficiency of 93.94% and a signal gain of 4.87 dB. Comprehensive microwave dielectric properties make LTMF<ZN_0.892+CB_1.2 become a candidate material for LTCC applications.