The blocking range of mobile phone jammer can be adjusted according tothe locations

Figure 2.6 shows the magnetic shielding and the equivalent magnetic circuit diagram
Clearly the magnetic flux is shielded with the shield in space appear shunt.The police can act more accurately and timely when capturing the suspect through using cell phone jammer.
So most of the magnetic flux flows through the shield, reaching less interference field strength of purpose. Since Rm and μ is inversely proportional to the magnetic shield which use steel, iron, permalloy high permeability magnetic material. The above conclusions both for constant magnetic field or low frequency alternating magnetic field is applied. Because low frequencies, eddy current generated by induced current shielding effect has been small.
Which will spread to the other side of the shield greatly reduced space of electromagnetic energy, played a role in shielding. The unique design of an antenna of cell phone jammercan avoid inconvenience of many-antenna blocking. Obviously, the greater the induced current and charge, the resulting reflected field, the stronger the heat loss (absorption loss) the greater the attenuation of the transmitted wave more. Therefore, the electromagnetic shielding conductive material should be used.

Shielding theory is not yet mature in the period, people tend to only use this method of calculation, but with the deepening of theoretical research, there has been applied to different frequency ranges and different calculation methods application object, which should be based on their specific situation to a variety of methods were used.
According to the application of the theory, the method should be mainly applied to the case of plane waves, both the high frequencies.The blocking range of mobile phone jammer can be adjusted according to the locations.

3.2 based on scattering theory calculation of shielding effectiveness.

When the shield structure size smaller than the wave length long, the incident electromagnetic wave (relative to the shield) do Reyleigh scattering, are discussed at this time can be high impedance magnetic field source and a low impedance source shielding.

There is no gap in the leak, the screen effect at high frequencies than low frequencies, the higher the frequency, the larger screen effect.The electric carrier wave is the technical core of the wholecell phone jammersystem.Inclusive type of cable screen effectiveness is also inclusive layer and the metal material and thickness, the better the conductivity, the thickness of the thicker, the higher the efficiency of its screen. It can be seen from the figure, the thickness of 0.6 m of the silver screen effect with heat-shrinkable tube 1.2 m thick nickel-plated heat-shrinkable tube the same.