Planar Ba(MgxTay)O3 Material for Emerging Microwave Technologies

Ba(Mg_xTa_y)O₃ based dielectric materials are typically used in many microwave applications due to its relatively high permittivity and low temperature coefficient of frequency. MURATA^reg manufactured a dielectric substrate based on Ba(MgxTay)03; we have characterised this substrate at microwave frequencies and at cryogenic temperatures using cryogenic split post dielectric resonator. The TE₀₁₁ mode of this resonator without and with sample is identified at frequencies of 10 GHz and 8.6 GHz respectively. The Transmission Mode Q factor Technique was used for data processing to ensure high accuracy of the measurements. The real part of the permittivity and the loss tangent varies between 24.37 and 24.4 and 4.2times10^-5 and 6times10^-5 respectively in the temperature range 25-295 K. The variation in permittivity is less than 0.2%. The low temperature coefficient of frequency and permittivity make Ba(Mg_xTa_y)O₃ substrate attractive to fabricate miniaturised planar antenna arrays and in other microwave applications where frequency stable substrates are needed.