The nameplate of the adapter of

Only EMI suppression strategies such as metal and iron materials like magnetic high to very low frequencies to achieve high shielding efficiency. Permeability of these materials will increase as the frequency decreases, while if the initial magnetic permeability also make a strong decrease, there is a mechanical method to make provision for the shield shape also reduces permeability. Here is the structure dimension of china cell phone jammer.In summary, the choice for the magnetic shield of high conductivity is very complex, usually EMI shielding materials to the supplier and the relevant advisory body to find a solution. In the high-frequency electric field, the use of thin metal shell or lining material as a good shielding effect can be achieved, but on condition that the shield must be continuous and completely cover the sensitive parts, no gaps or cracks (forming a Faraday cage).
The nameplate content of the adapter of china cell phone jammer should be accurate. EMI suppression have adopted many shell shield and shield gap as the way to achieve, most of the time following these simple principles can help to achieve EMI shielding: at the source to reduce interference; by shielding, filtering or grounding circuit isolation, and the interference generated enhanced anti-jamming capability sensitive circuits. EMI suppression, isolation and the low sensitivity of the circuit designer should be a goal of all these properties early in the design phase should be completed.The nameplate of the adapter of china cell phone jammer has no reverse sticking, misaligned sticking, missing sticking, mistaken sticking and tilting. Design engineers, the use of shielding materials is an effective method to reduce EMI. Shell now has a variety of shielding materials are widely used, from metal cans, thin metal sheet and foil to the fabric or the conductive coating and spray coating wear volume (such as conductive paint and zinc wire spray, etc.).
Shielding efficiency of shielding effectiveness of metal available (SE) of the shield to assess the suitability of its unit is dB, calculated as SEdB = A + R + B where A: absorption loss (dB) R: Return Loss (dB) B: correction factor (dB) (for thin shield of memory in the case of multiple reflections) will make a simple shield the electromagnetic field generated by one-tenth of the first down, that SE is equal to 20dB; some situations may require field strength will be reduced for the first one hundred thousandth of that SE should be equal to 100dB. The gap on the surface and bottom case of the adapter of cell phone jammer should be no more than 1mm with good fit and without looseness.Absorption loss is the electromagnetic energy loss through the shield when the amount of absorption loss calculation formula where f: frequency (MHz) Copper permeability σ: conductivity of copper t: thickness of the shield reflection loss (near field) depends on the nature of electromagnetic wave generation source and the wave source and the distance.