Magnetic and dielectric properties of conventional ceramics processed Ba3Co2Fe24O41 hexaferrite were investigated for microwave antenna miniaturization. Iron deficiency and optimizations of technology conditions have been used to control the high frequency properties of Co2Z materials. The properties of the materials were characterized by SEM, XRD, Vector Network Analyzer, and so on. The experimental results showed that Z-phase was the main phase with traces of Y-phases for all the tested samples and the resonance frequencies were above 2GHz. 3BaO·2CoO·10.4Fe2O3 samples sintered at 1050°C had a loss tanδμ of 0.07 with the permeability of 7.28 at 1GHz and the miniaturization factor n reached a value up to 10 under 2GHz. It was found that Z-type hexaferrites with iron deficiency and low sintering temperatures met the demands of low-loss tanδμ for microwave antenna applications.