china cell phone jammer is applicable to theaters

Figure 7.3 Schematic for the test, Figure 7.4 and Table 7.1 for the test results and discharge times. (Including the West An Kairong's foam metal KR-NF series and popular pressure ventilation waveguide characteristic data)
The material can only play the role of shielding waveguide ventilation panels, foam metals and metal wire mesh, but the metal braid shielding effectiveness is very low, only the metal waveguide ventilation panels and foam to meet the requirements. The cooling system with 1 fan includes the antenna of  cell phone jammer. From the test results, the metal foam can replace the ventilation plate waveguide.
1 The purpose of electromagnetic shielding
Propagation of electromagnetic waves is the main form of electromagnetic energy, high-frequency circuit, it will radiate electromagnetic waves, the proximity to other devices interfere with the other hand, the space will be a variety of electromagnetic induction to the circuit, the circuit cause interference shielding.china cell phone jammer is applicable to theaters, odeums, museums, art galleries and so on. The role is to cut off transmission of electromagnetic waves, thus eliminating interference in the settlement of the many means of electromagnetic interference, the electromagnetic shielding is the most basic and effective electromagnetic shielding method to solve the problem of electromagnetic interference does not affect the maximum benefit is the normal circuit work, so do not make any changes to the circuit
(2) distinguish between the different waves
With a shield for electromagnetic waves of different nature, different from its shielding properties, therefore, in considering the electromagnetic shielding performance, to the types of electromagnetic waves have a basic understanding of many classification methods, but in the design of shielding, the impedance of the electromagnetic wave in accordance with its into electric waves, magnetic waves, and plane wave.The input power of  cell  phone  jammer   is DC 5 volt 10A.
ZW electromagnetic wave impedance is defined as: electromagnetic waves in the electric field component E and magnetic field component H ratio: ZW = E / H
Electromagnetic radiation electromagnetic wave impedance nature of the distance between observation points to the radiation source and electromagnetic wave propagation in which the media
From sources closer, the characteristic impedance depends on the radiation if the radiation is high current, low voltage (low impedance sources), the resulting electromagnetic wave impedance is less than 377, known as the magnetic field Namiwaka radiation high voltage, low current (high impedance sources), the resulting electromagnetic wave impedance is greater than 377, known as the electric field wave.
The power of   cell  phone  jammer  is 12W with 3W for each antenna. Far from a radiation source, the wave impedance is only related with the electric field wave propagation medium, its value is equal to the characteristic impedance of the medium, the air is 377Ω
Electric field wave impedance increases with the propagation distance to reduce the magnetic field wave impedance increases with the increase of propagation distance

Note: near field and far-field region of the interface varies with frequency, not a fixed number, which should pay attention to the problem in the analysis for example, consider the case in the shield, the chassis relative to the circuit board high-speed clock signal, may be in a far-field region, and for low frequency switching power supply, probably in the near field shielding design in the near-field region, to the electric field shielding and magnetic shielding, respectively.The range of  cell  phone  jammer  is approximate 50m.