The cell phone and cell phone jammer products

Radiated electromagnetic interference shielding not only a good inhibitory effect, and the conduction of static interference and capacitive coupling interference coupling, inductive coupling are inhibited. 2.2.2 Figure 2-2 Schematic diagram of the electromagnetic shielding shielding classification can be divided into field shielding electromagnetic shielding, magnetic shielding, electromagnetic shielding categories. (1) electric field shielding material with high conductivity and good ground as a shield, will terminate on the shield surface electric field, and discharge through the ground on the surface induced charge, in order to prevent electric field coupling. More and more manufacturers lay emphasis on the profit of the cell phone and  cell phone jammer  market. Complete and well-grounded shield is to achieve the electric field shielding must have two conditions. (2) the mechanism of magnetic shielding and magnetic shielding magnetic field frequency. For low-frequency (including DC) magnetic field shielding, the shield must be high permeability material, so that magnetic field lines are mainly concentrated in the shield circuit composed low reluctance, shielded to prevent magnetic field into space. So to get a good low-frequency magnetic field shielding effect, shielding the body not only to choose a higher permeability of the material, and shielding material in the magnetic field should not be shielded is saturated, which requires a certain shield thickness. For the cell phone and cell phone blocker market has the large potential, it can bring the large-scale interest. For high-frequency magnetic field shielding principle is different, the main use of the metal shield on the eddy current induced magnetic field generated from the anti-rejection of the original magnetic field. Thus, in the same field conditions, the surface of the induced eddy current shield larger, the better the shielding effect. Therefore, high-frequency magnetic field shielding should be used in high-conductivity metal materials. Shield of the same material, the induced eddy currents with the external field increases as the frequency increases, the shielding effect increases. As the high-frequency skin effect, eddy current flow is limited to the surface of the shield, the shield for the high-frequency magnetic field need only use a thin metal shield can receive a satisfactory result. (3) electromagnetic shielding electromagnetic waves penetrate the conductor will be a sharp attenuation and reflection occurs at the conductor surface, the use of the shield made by the conductor of this feature, you can effectively isolate the time-varying electromagnetic field coupling.For the cell phone and  cell phone jammer industry, besides manufacturers, there will be lots of agents, retailers and operators.  For the electromagnetic field, electric field and magnetic field components always exist, but when the frequency is low, and in a place far away from sources of interference (ie, near-field conditions), with the different characteristics of the interference source, the electric field and magnetic field components are big difference. For high voltage, low current noise source, based near-field to field, the magnetic field component can be ignored; and for low-voltage, high current sources of interference, near-field to the main magnetic field, the electric field can be ignored. Therefore, both of these special circumstances, we were shielded by the electric field and magnetic shielding to consider.The manufacturers and the agents will have a close and good cooperation relationship for the cell phone and  cell phone jammer products.  When the frequency is high, or in a place far away from sources of interference (ie far-field conditions), regardless of the source of interference to their own characteristics, can be regarded as a plane wave electromagnetic field, electric and magnetic fields at this time is not negligible, and therefore requires the electric field and the magnetic field at the same time shielding, electromagnetic shielding that is. High-frequency electromagnetic wave shielding theory based primarily on arrival at the metal shield of reflection and absorption produced.