Ultra-low permittivity MgF2 ceramics with high Qf values and their role as microstrip patch antenna substrates

MgF2 ceramics have been prepared via the standard solid-state reaction method, and their microwave dielectric properties are reported for the first time. The permittivity (er) and quality factor (Qf) of MgF2 ceramics are closely related to porosity and lattice energy, respectively. The optimum microwave dielectric properties (epsilon(r) = 4.67, Qf = 92,233 GHz, and tf = 67.1 ppm/degrees C) are obtained when sintered at 1100 degrees C. The ultra-low permittivity and high Qf value distinguish MgF2 ceramic as a perfect substitute for the commonly used polymer-based FR4 epoxy in the coming 5G/6G era. The feasibility of using MgF2 ceramics as antenna substrates is demonstrated by fabricating an X-band microstrip patch antenna. The MgF2-based antenna resonating at 8.25 GHz exhibits excellent antenna performance with a return loss (S11) of 23.39 dB and impedance bandwidth of 318 MHz.

Automated summary

MgF2 ceramics were prepared using the solid-state reaction method, and their microwave dielectric properties were studied for the first time. The ceramics' permittivity (er) and quality factor (Qf) were found to be influenced by porosity and lattice energy, respectively. The best microwave dielectric properties (epsilon(r) = 4.67, Qf = 92,233 GHz, and tf = 67.1 ppm/degrees C) were achieved at a sintering temperature of 1100 degrees C. MgF2 ceramic, with its low permittivity and high Qf value, shows potential as a substitute for polymer-based FR4 epoxy in the 5G/6G era. An X-band microstrip patch antenna made with MgF2 ceramics demonstrated excellent performance, with a return loss (S11) of 23.39 dB and an impedance bandwidth of 318 MHz.