A Frequency Multiplier and Phase Modulation Approach for Mechanical Antennas Operating at Super Low Frequency (SLF) Band

In this paper, a novel scheme to increase the radiation frequency of a mechanical antenna to a multiple of its rotation frequency is presented. This approach is useful for antennas operating at the Super Low Frequency (SLF) band (30-300Hz) or Ultra Low Frequency (ULF) band (0.3-3kHz) without the need for rotating a permanent magnet or an electret at a very high speed. The proposed approach can also be used for mechanical phase modulation of data to be transmitted directly. In mechanical antennas, instead of using conventional antennas driven by electrical sources, the radiation is resulted from rotating magnets or electrets by mechanical sources. Our investigations indicate that by rotating a permanent magnetic bar sandwiched between two pairs of orthogonal bow-tie shaped layers of very high μ material, frequency multiplication can be accomplished at the expense of less radiated power. Slow position change of the μ material can also produce the desired phase modulation. Numerical simulations using ANSYS Maxwell, and measurements are performed here to verify these two concepts.