As shown in the given diagram the field pattern of electromagnetic waves is such that electric field is perpendicular to the magnetic field and both the fields are perpendicular to the direction of propagation.
The field pattern diagram no. 1 explains the further characteristics of electromagnetic field. Looking towards the field when it is propagated from the source it follows the pattern of the positive half cycle. It means that the electric field keeps on increasing from the reference point and after its maximum amplitude it comes back to its reference point again for the next half cycle. The behavior of electric field is the same but in opposite direction. In this way the electric field travels from source to load.
Looking towards the magnetic field of the diagram, it is very clear that the behavior of the magnetic field is exactly the same as for the electric field. But they remain perpendicular to each other.
If we consider the direction of propagation, we can come to know that while keeping themselves perpendicular to each other, the electric and magnetic fields are also perpendicular to the direction of propagation.
As shown in the given diagram no. 3 of electromagnetic field pattern for the dipole antenna, it is indicated that if the dipole antenna is mounted horizontally its electric field will also be horizontally polarized.
Looking towards the diagram no. 3 it is indicated that magnetic field H-field in circles the arms of the dipole and perpendicular to the E-field.
The field pattern of electromagnetic waves refers to the spatial distribution of the electric and magnetic fields that make up the wave. Electromagnetic waves exhibit certain characteristics that are inherent to their nature. Here are some key characteristics of the field pattern of electromagnetic waves:
- Perpendicular Oscillations: In an electromagnetic wave, the electric field (E) and magnetic field (B) oscillate perpendicular to each other and to the direction of propagation. This is known as transverse wave motion.
- Direction of Propagation: The electric and magnetic fields are also perpendicular to the direction of wave propagation. This characteristic is described by the right-hand rule, where the thumb represents the direction of propagation, the index finger represents the electric field, and the middle finger represents the magnetic field.
- Sinusoidal Nature: The variation of the electric and magnetic fields with respect to time and space follows a sinusoidal pattern. This means that the fields vary smoothly and continuously as the wave travels through space.
- Speed of Light: Electromagnetic waves travel at the speed of light in a vacuum, denoted by the symbol ‘c.’ In a vacuum, the speed of light is approximately 3.00 x 10^8 meters per second.
- Wavelength and Frequency Relationship: The wavelength (λ) and frequency (f) of electromagnetic waves are inversely proportional and related by the equation c = λf, where c is the speed of light. Higher frequency waves have shorter wavelengths, and vice versa.
- Energy Transport: Electromagnetic waves transport energy through space. The intensity of the wave, or the amount of energy carried per unit of time, is proportional to the square of the amplitude of the electric and magnetic fields.
- No Medium Requirement: Unlike mechanical waves, electromagnetic waves do not require a material medium for propagation. They can travel through a vacuum as well as through various materials.
- Polarization: Electromagnetic waves can be polarized. Polarization refers to the orientation of the electric field vector. Unpolarized light consists of waves with electric fields vibrating in all possible directions, while polarized light has its electric field confined to a particular plane.
- Interference and Diffraction: Electromagnetic waves exhibit interference and diffraction, which are phenomena associated with wave behavior. Interference occurs when two or more waves superimpose, leading to the reinforcement or cancellation of amplitudes.
Understanding these characteristics is fundamental to comprehending the behavior and properties of electromagnetic waves in various applications, including telecommunications, optics, and electromagnetic radiation.
