Design and Fabrication of a Frequency and Polarization Reconfigurable Microwave Antenna on a Printed Partially Magnetized Ferrite Substrate

Design of a polarization reconfigurable and frequency tunable patch antenna operating in the partially magnetized state of a ferrite substrate is presented in this paper. A low cost additive manufacturing process based on a custom iron-oxide magnetic ink (to realize the magnetic substrate) and a silver-organo-complex metallic ink (to realize the antenna) has been used to demonstrate a novel fully printed magnetically controlled antenna. The magnetic substrate is characterized for its magnetostatic and microwave properties. The ink shows a saturation magnetic flux density of 156 mT with a squareness of 0.26. A prototype patch antenna at 6 GHz is implemented on the magnetic substrate using inkjet printing. When excited by an external magnetic field the antenna shows frequency splitting and polarization reconfigurability. The measured results agree well with the simulation model of the antenna in the partially magnetized state. A maximum tuning range of 16.7% and 5% for the two splitted frequency points is obtained with circular polarizations of opposite sense. The results show the viability of reconfigurable and tunable RF components on partially magnetized substrates through low cost additive manufacturing techniques.