A novel NaMg(1-x)Znx(PO3)3 microwave dielectric ceramic with an ultra-low dielectric constant for LTCC application

In millimeter-wave communication, signal delay becomes increasingly pronounced as the operating frequency of the equipment rises. To accelerate signal transmission, substrates with low dielectric constants (ε r  < 6) are required. This study synthesized a novel microwave dielectric material, NaMg (1- x ) Zn x (PO 3 ) 3 (NMZPO), using the conventional solid-phase method. The microwave dielectric properties of NaMg(PO 3 ) 3 ceramics were enhanced by substituting Mg 2+ with Zn 2+ . Specifically, Zn 2+ doping increased the ceramics' densification and reduced dielectric loss. The NaMg 0.9625 Zn 0.0375 (PO 3 ) 3 ceramic exhibited optimal microwave dielectric properties at sintering temperature 880 °C for 4h: ε r  = 4.49, Q ×  f  = 58237.2 GHz (at 17.792 GHz), τ f  = −50.6 ppm/°C. In addition, NMZPO ceramics demonstrate excellent chemical compatibility with Ag electrodes. These findings indicate that NMZPO represents a promising candidate for the next generation of ultra-low dielectric constant LTCC materials.