A microwave dielectric material for microstrip patch antenna substrate

High quality factor and near-zero temperature coefficient of resonant frequency (τf) are the two key issues for a certain microwave dielectric material system used in microstrip patch antennas. ZnTiO3-based ceramics is a promising candidate for microstrip patch antennas. On inhibiting the decomposition of ZnTiO3by adding sufficient amount of MgO, high quality factor microwave dielectric material (Zn0.7Mg0.3)TiO3was obtained. The deviations between theoretical and observed dielectric polarizabilites, the packing fraction, and bond valence were calculated to analyze correlation between structure and properties of (Zn0.7Mg0.3)TiO3. TiO2was added to adjustτfof (Zn0.7Mg0.3)TiO3, and 0.82(Zn0.7Mg0.3)TiO3–0.18TiO2with anεrof 28.5, aQfof 125,050 GHz, and a near-zeroτfwhich satisfied the requirement as a substrate material for microstrip patch antenna was obtained at 1100 °C. In addition, a dielectric microstrip antenna was designed and fabricated using the proposed dielectric materials. The microstrip patch antenna exhibited a −34.96 dB return loss and a 1.05 voltage standing wave ratio at 2.5 GHz.