High-Q Microwave Dielectric SrTiO3-Doped MgTiO3 Materials with Near-Zero Temperature Coefficient of Resonant Frequency

The microwave dielectric properties of the (1- x )MgTiO 3 – x SrTiO 3 system have been investigated. The objective of the present work is to compensate for the negative temperature coefficient of the resonant frequency (τ f ) of MgTiO 3 by addition of SrTiO 3 . The variation in microwave properties of the system significantly depends on the amount of SrTiO 3 present, and they can be matched using mixing rules. With increasing x , the dielectric constant ( ε r ) increased and the quality factor ( Q f ) decreased. A ceramic sample with x =0.036 of SrTiO 3 , sintered at 1270°C for 2 h, and having a near-zero temperature coefficient of resonant frequency (τ f ) of -1.3 ppm/°C can be obtained.