A new approach on improving the efficiency of a frequency reconfigurable rectangular microstrip patch antenna using magneto-static responsive structures (MRSs) is proposed. In particular, a 1.5 mm × 1.5 mm × 0.508 mm volumetric structure consisting of two parallel conducting plates separated by a dielectric material summarises the overall MRS embodiment. The dielectric material has a cylindrical cavity (i.e. drilled cavity) with a diameter of 0.9 mm and is partially filled with conducting particles (i.e. silver-coated nickel-based cores) that respond to magneto-static fields. Then, when a small permanent magnet is placed close to the MRS, the conducting particles form columns orientated in the direction of the field lines and connect the two conducting plates, acting as an RF switch. Next, to demonstrate the benefits of the MRS, the efficiency of a reconfigurable patch antenna is investigated. Finally, for comparison, the MRS-based reconfigurable antenna is compared with the measured and simulated efficiency of a reconfigurable patch antenna with the same geometry that uses P-region Intrinsic-region N-region (PIN) diodes. It was shown that the MRS-based design had a much better efficiency (50% larger).