Low sintering temperature and microwave dielectric properties of H3BO3-added Li2Ti0.85(A1/3Ta2/3)0.15O3 (A = Zn, Mg) ceramics for patch antenna application

Li2Ti0.85(A(1/3)Ta(2/3))(0.15)O-3 + xwt.% H3BO3 (A = Zn, Mg; 1.0 <= x <= 5.0) (LTATB(x)) ceramics were fabricated by the traditional solid phase synthesis method. The LTATB(x) ceramics belong to monoclinic structure which was checked by the X-ray diffraction (XRD). The microstructure of Li2Ti0.85(A(1/3)Ta(2/3))(0.15)O-3 ceramics could be improved by the addition of H3BO3, which was directly observed by the scanning electron microscope (SEM). The optimum dielectric properties (107,490 GHz and 57,543 GHz) of Li2Ti0.85(A(1/3)Ta(2/3))(0.15)O-3 ceramics were obtained when the x values are equal to 1.0 and 3.0, respectively. Since the addition amount reached 5.0, the sintering temperature declined to 900 degrees C and 950 degrees C, respectively. The patch antennas prepared with LTZTB(1.0) and LTMTB3.0 ceramics were simulated and measured. The results from measured indicated that the S11 parameters in LTZTB(1.0) and LTMTB3.0 based patch antenna are less than -15.0 dB, and the VSWR is close to 1.0, which basically meets the application requirements of external antenna.