Analysis of Radiation Characteristics on Rotating-magnet Based Mechanical Antenna

Propagation Characteristics and Magnetic Field Distribution of Rotating Magnet-Based Mechanical Antenna in the Air-Seawater-Seabed Three-Layer Medium

“…Figure 1 shows the system architecture of RMBMA [8], which consists of a rotating magnetic source (permanent magnet) and a rotating servo system (drive motor and controller). Te information loading of RMBMA is realized by mechanical driving, and the symbol data are loaded into the mechanical motion state of the magnetic source.…”

“…Te mechanical rotation of a permanent magnet can directly generate a static strong magnetic feld, which is expected to realize low power consumption and miniaturization of lowfrequency electromagnetic emission systems. Te Sixty-Tird Institute of the National University of Defense Technology has carried out systematic modeling analysis and theoretical research on the radiation mechanism of rotating permanent magnet mechanical antennas and analyzed the radiation distribution characteristics of RMBMA and the general analytical expression of electromagnetic feld distribution [8]. Te University of California, Los Angeles, has realized the array of RMBMA, so that the antenna can have a large frequency adjustment range, which brings great convenience to signal modulation [9].…”

“…However, the actual marine environment is complex and changeable, and there are still many technical problems to be solved in underwater wireless communication. For the underwater communication of RMBMA, [8] equivalents RMBMA to two orthogonally placed magnetic dipoles with a phase diference of 90 °, which is used to study the near-feld, farfeld, and attenuation characteristics of RMBMA in infnite air and seawater space. In [12], the equivalent relationship between the rotating permanent magnet and the orthogonal current loop was given.…”

“…Te cross-domain propagation of RMBMA in the air-seawater two-layer medium and the magnetic feld distribution near the sea surface were analyzed by using the orthogonal magnetic current element decomposition method and Sommerfeld integral. Te authors in [13] analyzed the magnetic feld radiation attenuation characteristics of horizontal rotation and vertical rotation of magnetic sources in two-layer media. Te authors in [14] preliminarily analyzed the propagation characteristics of RMBMA in an air-seawater-seabed three-layer medium when the magnetic source and the receiving point are located at diferent depths.…”