A printed dipole reconfigured with magneto-static responsive structures that do not require a directly connected biasing circuit

An initial study of novel Magneto-static Responsive Structures (MRSs) and their application to the frequency reconfigurability of a printed dipole antenna is presented here. The embodiment of the MRSs consisted of a cylindrical cavity with a diameter of 0.9 mm drilled into a 20.0 mil thick 1.5 mm × 1.5 mm TMM4 substrate. The cavities were partially filled with silver coated magnetic particles and covered on the top and bottom with copper tape. The conducting magnetic particles responded to an externally applied magnetic field and formed columns in the direction of the magnetic field lines. The columns connected the top and bottom conducting planes, acting as a switch. It was demonstrated that the electrical length of an antenna could be changed and the resonant frequencies could be reconfigured from 1.5 GHz to 1.9 GHz by incorporating the MRSs into the dipole antenna and controlling the ON and OFF states of the MRS switch. Overall, it was shown that the simulated results agreed well with the measurements. It was also demonstrated that the proposed MRSs do not need directly connected biasing circuitry, making them particularly useful for complex antenna designs.