When the BH-201 cell phone jammer is installed in the height of 1.8 to 2 meters

It would be complicated wires, so high frequency circuit ground wire is often avoided, and the circuit unit, each finding the nearest large area of ground, connected directly to the shortest path, resulting in more, and high frequency for the ground material is very particular, but the principle is area should be large enough enclosure is large enough of it, but in fact there are things you must first declare that the connection must be as short as possible, then it's best to remember that the nearest point of access must ensure that every point in the same plane the only effective, but still an old one this is just one of the means only, way to many high-frequency ground neither the same purpose, this is oh, need to study the interference with ground ground ground design is the design EMC design attention to everyone, but do not know how to do a problem. Please keep the cell phone jammer away from thermal resistant objects. Understand the mechanism of interference caused by ground after the ground in the design and implementation, when there is a clear line of thought. Period from the introduction of the principle of interference caused by ground to start, so that readers understand the key design and principles of ground. 1 What is the ground? What is the ground? A safety ground and signal ground two. The former is to ensure personal safety, safety of equipment and set up ground, which is working to ensure the correct set of circuit ground. The main cause is the circuit interference signal, the signal so the discussion here only to the issue. Signal to the general definition is: the circuit reference point potential. More appropriate to say that this definition is that we design the circuit of a hypothesis. When the BH-201  cell phone jammer  is installed in the height of 1.8 to 2 meters, the shielding range would be largest.From this definition it is impossible to analyze and understand some of the ground interference problems. From now on, our analysis of electromagnetic compatibility problems, use the following definition. Ground is the signal current flows back to the signal source impedance path to ground. Since the ground is a current path, then according to Ohm's law, there is a ground voltage line; since in line with voltage, indicating the ground is not an equipotential body. Thus, we designed the circuit, on the ground potential on certain assumptions no longer valid, so the circuit will be various errors.Do not point the antenna of cell phone blocker at the direction of base station. This is the substantive ground interference. Ground impedance be? 2 ground impedance be? A difficult to understand the problem is that we in the design ground, the ground resistance are so small, then the potential difference to how the line will result in large errors of the circuit. Understand this, to understand the composition of ground impedance. Ground impedance Z by the Ministry of resistance and inductance part in two parts, namely: Z = RAC + jωL. Resistance components: resistance of the conductor is divided into RDC DC resistance and AC resistance of RAC. For AC current, resistance component due to skin effect, the current focus on the conductor surface, leading to the actual current cross-section decreases, the resistance increases, the DC resistance and AC resistance of the relationship is as follows: RAC = 0.076rf12RDC where: r = wire radius, the unit cm, f = frequency of the current flowing through the wire, the unit Hz, RDC = dc resistance of the wire, the unit Ω.Do not point the antenna of  cell phone jammer  at the direction of base station, otherwise the working effect would be influenced.