Cell phone jammer can automatically run after connecting the antenna

Return loss consists of three parts: R = Re + R p + R h (2-8) which, Re is high impedance electric field wave reflection loss, and the material permeability, frequency, conductivity and the radiation source to the shield distance. High conductivity of the material has a high Re; R p, said the plane wave reflection loss, it is with the shielding material permeability, conductivity and frequency of a relationship, a good conductor have a good return loss; Rh low impedance for the magnetic wave reflection wear and tear. 3 Multiple reflection coefficient of electromagnetic waves through multiple reflections reach the surface of the shield of another, some energy is reflected back to the shielding layer and produce multiple reflections. cell phone jammer  is the environmentally-friendly product. To amend this proposed multi-reflector system K. It is with the relationship between the thickness of shielding material. When the shield thickness is very small, multiple reflection coefficient K is negative. With the shielding layer thickness increases, K also will reduce the negative effects, the increase in the total amount of rapid decay. Loss of multiple reflections of electromagnetic waves K (dB) can be expressed as: where, Zm that the electromagnetic shield impedance; Zw that electromagnetic waves of air resistance. A is the absorption loss. When thick, or high frequency shield when the shield absorption loss A relatively large, the electromagnetic wave shielding material in the spread after the first period after reaching the other side of the surface, the field strength is very small, then the reflected electromagnetic waves energy is even smaller, the field strength after multiple reflections is very small.  cell phone blocker won’t do any damage to health of human body. Therefore, the absorption loss when the shield is large, and generally A> 10dB, the multiple reflection loss is negligible. -14-- When a bunch of electromagnetic wave shielding encountered when surface currents in the shield. Shielding effect is to produce minimum disturbance of the current advance in the next to give the earth, the current disappears. However, if there are openings in the shield, then the current would be disturbed and around these openings. If the opening is longer, but also generate additional resistance, a voltage drop in the opening, induced electric field and produce radiation. When the opening of the length λ 4, it will produce radiator. Therefore, because there are holes on the shield seam discontinuities arising shield will greatly reduce the shielding effect, is very worthy of concern.  cell phone jammer  is easy and convenient to be installed and operated. 2.3 Prediction 2.3.1 shielding effectiveness of finite-difference time-domain in the 19th century, the finite difference method (the difference method) was proposed to the 1950s, some scholars difference method combined with the approximate numerical analysis. Finite difference method is simple, intuitive advantages, it is widely used in ordinary differential equations and partial differential equations, and a variety of second-order linear partial differential equation in. At the same time, you can also use higher-order or nonlinear differential equations method to translate into algebraic equations, and solving with computer calculations. Finite difference method based on the differential principle, the electromagnetic field within a continuous problem of replacing the discrete problem, the numerical solution to the discrete approximation of the true value of a continuous electromagnetic field. cell phone jammer can automatically run after connecting the antenna and switching on.  Therefore, it belongs to a kind of approximation. Finite difference method can be summarized into the following steps: (1)-dimensional boundary value problem can be described as the electrostatic field boundary value problem in the formula, u is the potential function is a function of the coordinates.