T. Sato, 2016-11-13Sleeve dipole antennas will have properties, such as radiation pattern, similar to dipole antennas.
Small sleeve antenna may sometimes be used in proximity to simulate mobile transmitters, and electric and magnetic field pattern in proximity of the sleeve antennas may of interest.
Here, electric and magnetic field patterns 5 cm from 435 MHz sleeve antenna defined in ISO 11452-9 are estimated with NEC.
|Distance||Electric field||Magnetic field|
In this simulation, sleeve is modeled with number of thin wires, and the sleeve and thin element are excited at the base of the thin element.
As in halfwave dipole, potential on the elements are high at both ends of the elements, and current are high at the feed point. As expected, in proximity, high electric field is expected near both ends of the elements, and high magnetic field is expected near the feed point.