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Theory of electric and magnetic field in electromagnetic waves

１　Electromagnetic waves have no electric field　　　　　　　　　　　　　− 日本語 − 　　 ＜Reference 王様は裸＞

２　Unclear about radio waves 　　　　　　　　　　　　　　　　　　　− 日本語 −

３ Form of current　　　　　　 　　　　　　　　　　　　　　　　　　　　　 − 日本語 − ＜Reference Comment＞

４ Electrical and Magnetic forces　　　　　　　　　　　　　　 　− 日本語 −

５ Electromagnetic waves are traveling magnetic fields 　　　　 　 − 日本語 −

６ Generate electromagnetic waves 　　　　　　　　　　　　− 日本語 −

７ Receive electromagnetic waves 　　　　　　　　　　　 　− 日本語 −

８ Polarization 　　　　　　　　　　 　　　 　　　　　　　　 − 日本語 −

９ Insertion device for synchrotron　　　　　　 　　　　　　　　　　　　　 　− 日本語 −

１０ Longitudinal and Transverse Waves 　　　　　　　 　　　　　　 　　　　− 日本語 −

１１ Vibration of string 　　　　　　　 　　　　　　 　　　　 　 　 　　　− 日本語 −

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　Mar./18/2024

＜ 1　Magnetic field generated by a dipole antenna ＞

Figures 1, 2, and 3 show schematically the magnetic field generated by a transmitting dipole antenna.

If, as illustrated, radio waves have no electric field and are formed by a traveling magnetic field, then it is clear that radio waves can propagate in a vacuum with no medium. And it does not require any displacement currents or electric lines of force. The unclear matter described above under "Unclear about radio waves" is eliminated.

In the figure, orange indicates the magnetic field in the direction from the front to the back of the screen, and blue indicates the magnetic field in the direction from the back to the front of the screen, and the same color scheme is used below to indicate the direction of the magnetic field.

Figure 2 shows the magnetic energy of radio waves as an equivalent magnet, such as a permanent magnet, substituted. The magnetic field generated by the dipole antenna expands and propagates in the radial direction while maintaining its magnetic energy is shown as a ring-shaped magnetic field formed by several small equivalent magnets connected in series, which are pushed apart and travel in the radial direction, as a substitute.

　

Figure 3 shows a magnetic field traveling in one of the radial magnetic field. Magnetic field strength and polarity are indicated by the length and direction of the arrows. If a sine-wave varying signal is supplied to the antenna from the supply power source, a magnetic field that varies sine-wave in intensity and polarity is generated and travels in the direction of radiation in a flowing manner. The traveling magnetic field attenuates inversely proportional to the square of the distance traveled away from the antenna.

　

The dipole antenna generating a magnetic field is described in "Generate electromagnetic waves", and the dipole antenna receiving a magnetic field is described below in "Receive electromagnetic waves".

＜ 2　Magnetic field generated by a dipole antenna and that generated by a pyramidal horn antenna ＞

Figure 4 schematically shows the magnetic field generated when a reflector is placed behind dipole antenna in Figure 1 above.

Figure 5 schematically shows the magnetic field generated by a vivaldi antenna, which substitutes dipole antenna of Figure 1 above for the upper and lower conductor plates.

Figure 6 schematically shows the magnetic field generated by a double-ridge pyramidal horn antenna with vivaldi antenna of Figure 5 above in the horn.

Figure 7 schematically shows the magnetic field generated by a pyramidal horn antenna in its basic configuration with no upper and lower ridges.

As described above, the magnetic field generated by a dipole antenna and the magnetic field generated by a pyramidal horn antenna are both rotating magnetic field with the axis of rotation orthogonal to the direction of travel. Therefore, both magnetic fields are same form of magnetic field.

＜ 3　Magnetic field generated by a conical horn antenna ＞

Figure 8 shows schematically the magnetic field generated by a conical horn antenna. The magnetic field generated by the conical horn antenna is a ring-shaped magnetic field that rotates around an axis of rotation in the direction of travel.

Incidentally, some conical horn antennas generate a magnetic field in a form similar to that of a pyramidal horn antenna, or dipole antenna, by inserting a transducer between the feeding cable and the conical horn antenna, so care should be taken not to confuse them.

＜ 4　Magnetic field or Light generated by a synchrotron ＞

Figure 9 shows schematically the magnetic field (synchrotron light) generated by the synchrotron. In a synchrotron, the direction of the electrons moving at the speed of light is bent by an orthogonal bending magnetic field, which separates the electrons from the magnetic field traveling parallel to them. This separated ring-shaped magnetic field traveling at the speed of light becomes synchrotron light.

Magnetic field generated by conical horn antenna and synchrotron with an axis of rotation in the direction of travel can be extracted by passing them through a blind-like filter with multiple conductors in parallel, as shown in Figure 10, to extract magnetic field with an axis of rotation orthogonal to the direction of travel, such as those generated by a pyramidal horn antenna.

This event indicates that the magnetic field with the axis of rotation parallel to the direction of travel and the magnetic field with the axis of rotation orthogonal to the direction of travel are same type of magnetic field.

There is no problem in considering that the natural light from which polarization can be extracted in any direction by rotating the polarization filter is a ring-shaped magnetic field whose axis of rotation is in the direction of travel. Therefore, unclear matter to polarization of natural light as described above in "Unclear about radio waves" is eliminated.

Furthermore, if the light is a ring-shaped magnetic field separated from electron moving at the speed of light, as in synchrotron light, then the magnetic field generated by a single electron, the smallest unit of electricity, is the smallest unit particle of light. This is the photon. Thus, unclear matter to photon is eliminated.

＜ 5　Appendix ＞

It is the far field (beyond λ/2π) where there is no electric field. In the near field, the electric fields cannot be ignored as the various equations show, because they are directly coupled and affect each other.

＜ 「Electrical and Magnetic forces」・「Generate electromagnetic waves」 ＞