Angular momenta in fields from a rotational mechanical antenna
arXiv:2110.03686 · doi:10.1088/2399-6528/ac41a9
Abstract
Mechanic antennas provide opportunities for human portable, VLF communications, where a rotational dipole emits EM signals with angular momenta. In this paper we analytically derive the electromagnetic fields from a rotational electric dipole using Fourier transform method, and find that the radiated fields from the rotational electric dipole carries nonzero energy flow density in both orbital and spin angular momentum (AM) parts by AM flux tensors. Intuitively, a rotation of a dipole induces a longitudinal orbital angular momentum and a longitudinal spin angular momentum both circulating in the rotation direction. And the binding force for the rotational electric dipole is then shown to result mainly from the Coulomb fields. We believe that our work can provide novel communication designs for portable mechanic antennas.
arXiv comment18 pages, 4 figures
References in corpus (11)
- Spin-orbit interactions of light
- Transverse and longitudinal angular momenta of light
- Encoding many channels in the same frequency through radio vorticity: first experimental test
- Internal flows and energy circulation in light beams
- Conservation of the spin and orbital angular momenta in electromagnetism
- Fundamental Efficiency Limits for Small Metallic Antennas
- Helicity and Angular Momentum. A Symmetry based framework for the study of Light-Matter Interactions
- Rotating optical microcavities with broken chiral symmetry
- Rotation-induced Asymmetry of Far-field Emission from Optical Microcavities
- Generation of Orbital Angular Momentum by a Point Defect in Photonic Crystals
- Asymmetry and spin-orbit coupling of light scattered from subwavelength particles