“…Recently, a number of material researchers have focused their research on lowering the sintering temperatures of microwave dielectric ceramics to meet the LTCC requirements. Three approaches are usually used to develop low-firing microwave dielectric ceramics: (a) addition of oxides or glass with low melting temperature [4][5][6][7][8][9][10][11], such as V 2 O 5 , CuO, LiF, and B 2 O 3 ; (b) utilization of ultra-fine particles for raw materials [12,13]; (c) development of novel glass-free low-firing dielectric ceramics, including Bi 2 O 3 -TeO 2 , TiO 2 -TeO 2 , CaO-TeO 2 , BaO-TeO 2 , ZnO-TeO 2 binary systems, BaO-TiO 2 -TeO 2 ternary system, and Bi 2 W 2 O 9 systems [14][15][16][17][18][19][20][21]. Our recent research [22] showed that Bi 2 O 3 -MoO 3 binary system is a new ultra-low-firing microwave dielectric material.…”