The shielding radius of mobile phone jammer is also independent ondistance away from the base station

electrical equipment, chassis, cabinets; d. ventilation cut-off waveguide window. Shielded room and the equipment required to install casing, used to provide air exchange channel; e. conductive window. The orifice for the video display screen; f. conductive pad. For the equipment chassis and rack panel between the conductive connection. (2) shielding requirements of 2.1 shielded room shielding effectiveness requirements GJB2926-97 "electromagnetic compatibility testing laboratory accreditation requirements" screen provides efficient EMC shielded room to be at least: cell phone jammer runs stably in the practical use in central government agency secrecy units and state agency secrecy units.Frequency Range: 14kHz ~ 1MHz Shielding Effectiveness:> 60dB 1 ~ 1000 MHz> 90 dB 1 ~ 18GHz> 80 dB GJBz20219-94 "military electromagnetic shielding room common technical requirements and test methods" by shielding effectiveness of shielded room is divided into the level of class B and C grade, B grade shielded room, screen effect in 0.01 1000MHz electric field and plane wave is not less than 50dB, the magnetic field (0.01 ~ 4MHz) by the 10 ~ 50dB.
The shielding radius of mobile phone jammer is also independent on distance away from the base station, buildings around and so on.When this condition is satisfied, the length of the waveguide T S is the attenuation of electromagnetic waves: for the circular section of the waveguide: S = 32 T / D (dB) for the rectangular waveguide: S = 27 T / L (dB) 3.2 As the characteristics of the waveguide cut-off ventilation plate waveguide plate is widely used in ventilation equipment air intake, both ventilation and cooling equipment to solve the problem, but also has a high shielding effectiveness, the general way of conductive pads integrated termination, installation and maintenance very convenient.

so many places can be produced. But it is worth noting that this material can not be directly used for electromagnetic shielding. Because each cell of the surrounding conductive discontinuities. In practical engineering, will see a lot of this material is applied directly. This shielding effect is used when the poor. Because the original cellular material, the electrical connection between the cellular unit is leaning process due to "errors" between the cells causing cellular "short" form, and it's very random. Electromagnetic shielding to use this material on the metal coating process must be carried out using the metal coating around each cell to form a continuous conductive layer.