• • Standardized resonant methods achieve εr measurement errors below 1% and a tanδ detection limit of 10^-5, yet accurate measurement of ultra-low dielectric loss (tanδ < 10^-5) remains challenging due to conductor loss and spurious mode interference, directly impacting the reliability of high-Q filter design for 5G/6G base stations.
• • Cold sintering process achieves ceramic densification below 300 °C, reducing energy consumption by over 97% compared to conventional sintering (>1000 °C), which mitigates volatilization of active elements and enables co-firing with low-melting-point electrodes for miniaturized devices.
• • Machine learning models predict key dielectric properties with a coefficient of determination (R²) higher than 0.9, accelerating the exploration of novel MWDCs; however, the temperature coefficient τf is often treated as a constant despite its actual temperature dependence, limiting predictive accuracy under thermal cycling.
• • Device insertion loss is maintained below 1 dB in high-performance substrates, resonators, and filters for 5G/6G communications, but the role of multiscale defects in anharmonic lattice vibrations is not fully quantified, and the cation rattling effect has not been systematically integrated into classical dielectric theory, impeding rational design of ultra-low-loss materials.