The far field region in antenna refers to the region where the electromagnetic fields radiated by the antenna become more stable and independent of the distance from the antenna. In this region, the electric and magnetic fields are predominantly transverse, propagating as electromagnetic waves. The far field region is important for applications such as long-distance communication and radar systems.
The Fraunhofer zone is a region far away from a radiating source where electromagnetic waves become approximately parallel and have a stable wavefront. In this zone, the wave characteristics are mainly determined by the spatial distribution of the source rather than the distance traveled. This zone is commonly utilized in fields such as antenna theory and optics for analyzing wave propagation.
if we're talking about a short dipole, you have {E.H} field depending by r^(-k), where r is distance between antenna's feed and point of {E,H} calculus and k is >=1. In far field, you can imagine r>>1, so r^(-k) contribution is lower for greater k and you can approximate {E,H} expression by considering only the contribution with the lowest k. This make Poynting vector become real, according with the assumption that far field radiation power is active, near field one has also a capacitive contribution.
According to Faraday's law: "When current is passed through a conductor, an EM field is produced surrounding it." As an antenna contains one or more conductors, the terminals of which are connected to some voltage, when this voltage at the terminals is applied, it produces/induces the alternating current which radiates the elements in the electromagnetic field. (Transmission) The reverse of this occurs in reception; where the electromagnetic field from another source induces an alternating current in the antenna, and a corresponding voltage at the antenna's terminals.
The field in this region is 25% weaker compared to the surrounding areas.
RF energy is transmitted through an electromagnetic field. Once the field meets the receiving antenna, voltages are produced by using the antenna as a conductor. RF voltages induced by the antenna are passed on to the receiver then reconverted to transmitted RF information.
Rephrase the question, What antenna?
The Fraunhofer zone is a region far away from a radiating source where electromagnetic waves become approximately parallel and have a stable wavefront. In this zone, the wave characteristics are mainly determined by the spatial distribution of the source rather than the distance traveled. This zone is commonly utilized in fields such as antenna theory and optics for analyzing wave propagation.
if we're talking about a short dipole, you have {E.H} field depending by r^(-k), where r is distance between antenna's feed and point of {E,H} calculus and k is >=1. In far field, you can imagine r>>1, so r^(-k) contribution is lower for greater k and you can approximate {E,H} expression by considering only the contribution with the lowest k. This make Poynting vector become real, according with the assumption that far field radiation power is active, near field one has also a capacitive contribution.
Its is at the ski mountain
The region of the Earth's magnetic field is called the magnetosphere. It extends far into space and protects the Earth from solar wind particles and cosmic radiation. The magnetosphere is created by the interaction between the Earth's magnetic field and the solar wind.
the far north region
Its on ski hill
The RFID is powered by its own antenna. When in the presence of a pulating magnetic field, the antenna generates a signal that can power up the RFID, causing it to generate its code on top of that field.
Yes, you certainly can. But the car antenna probably won't work as efficiently as one that's specifically designed for CB. That means you probably won't be able to hear as far or talk as far as you could if you used the right antenna.
According to Faraday's law: "When current is passed through a conductor, an EM field is produced surrounding it." As an antenna contains one or more conductors, the terminals of which are connected to some voltage, when this voltage at the terminals is applied, it produces/induces the alternating current which radiates the elements in the electromagnetic field. (Transmission) The reverse of this occurs in reception; where the electromagnetic field from another source induces an alternating current in the antenna, and a corresponding voltage at the antenna's terminals.
yes
All types... depending on frequency and application. Lower frequency RFID's are typically near field and use inductive antenna designs, higher frequency ones use far-field designs. Low frequency RFID's like the TIRIS pet ID's use coils of wound wire. HF type RFID's like MiFARE use simple planar loop antenna designs. Most VHF RFID's use dipole and modified dipole designs with reflector elements. UHF and microwave RFID's frequently use patch and slot antenna designs.