A Study on MgO-Ta sub(2)O sub(5) System Ceramics for Microwave Component Application

In this study, the microwave dielectric properties of the Mg sub(4)Ta sub(2)O sub(9) and Mg sub(5)Ta sub(4)O sub(15) ceramics with composition ratio and sintering temperature were investigated and the dielectric resonators with these ceramics were simulated. TiO sub(2) was doped in the Mg sub(4)Ta sub(2)O sub(9) ceramics for improvement of temperature property. The (1-x)Mg sub(4)Ta sub(2)O sub(9)-xTiO sub(2) and Mg sub(5)Ta sub(4)O sub(15) ceramics were prepared by solid-state reaction method. According to the X-ray diffraction data, the (1-x)Mg sub(4)Ta sub(2)O sub(9)-xTiO sub(2) ceramics had main phase of the Mg sub(4)Ta sub(2)O sub(9) and MgTi sub(2)O sub(5) peaks were appeared by additions of TiO sub(2). In the Mg sub(5)Ta sub(4)O sub(15) ceramics, the Mg sub(4)Ta sub(2)O sub(9) and MgTa sub(2)O sub(6) phase were coexisted and Mg sub(5)Ta sub(4)O sub(15) phase was appeared with increments of sintering temperature. Microwave dielectric properties of (1-x)Mg sub(4)Ta sub(2)O sub(9)-xTiO sub(2) ceramics were affected by MgTi sub(2)O sub(5) and TiO sub(2) phase. The quality factor had a little decrement compared to pure Mg sub(4)Ta sub(2)O sub(9), but there was excellent improvement in TCRF by addition of TiO sub(2). Densifications of the Mg sub(4)Ta sub(2)O sub(9) and MgTa sub(2)O sub(6) and existence of the Mg sub(5)Ta sub(4)O sub(15) phase had influence on the microwave dielectric properties of the Mg sub(5)Ta sub(4)O sub(15) ceramics. Dielectric constant, quality factor and TCRF of the (1-x)Mg sub(4)Ta sub(2)O sub(9)-xTiO sub(2) and Mg sub(5)Ta sub(4)O sub(15) ceramics sintered at 1450C were 11.56-22.5, 24980-186410GHz, -36.02-+19.72ppm/C and 8.2, 89473GHz, -10.91ppm/C, respectively. ADS was used for simulation of DR. The simulated DR with the 0.5Mg sub(4)Ta sub(2)O sub(9)-0.5TiO sub(2) and Mg sub(5)Ta sub(4)O sub(15) ceramics had the S sub(21) of -35.034dB at 11.97GHz and -28.493 dB at 10.50GHz, respectively.