What are the functions of precision shields? -Hardware

Generally, there are two precision shields in mobile phones, which cover the RF and BB sections respectively. If it is a baseband circuit, for example, the core is an AMR9 high-speed circuit, or there are some inductive boost components inside the baseband. On the one hand, the shielding cover of the mobile phone prevents external electromagnetic radiation from affecting the radio frequency circuit, and also prevents radio frequency interference from affecting the normal operation of the devices in the baseband circuit. The work is like the precision shielding cover for mobile phones. Dongguan shielding cover manufacturers explain in detail that the shielding body surrounds the interference sources of components, circuits, assemblies, cables or the entire system to prevent the interference electromagnetic field from spreading out; use the shielding body to connect the receiving circuit , Equipment or systems are wrapped up to prevent them from being affected by external electromagnetic fields. It can not only be said that the shielding cover is to prevent radiation or be radiated. Because the shielding body absorbs energy (eddy current loss), reflects energy (the interface reflection of electromagnetic waves on the shielding body) and cancels the energy electromagnetic induction for external interference electromagnetic waves from wires, cables, components, circuits or systems, and internal electromagnetic waves. The reverse electromagnetic field is generated on the shielding layer, which can offset the effect of departmental interference electromagnetic waves), so the mobile phone shielding cover material has the effect of reducing interference. For example, if the radio frequency is a zero-IF circuit, there may be local oscillator leakage. On the one hand, the precision shielding cover of the mobile phone prevents external radiation, and it can also prevent the external interference signal from causing interference such as intermodulation and intermodulation on the demodulation. When the frequency of interfering electromagnetic waves is low, materials with high magnetic permeability should be used, so that the lines of magnetic force are limited to the inside of the shield and prevent spreading to the shielded space. The shield can prevent external radiation and interference by radiation. When the frequency of the interference electromagnetic field is high, the eddy current generated in the low-resistivity metal material is used to counteract the external electromagnetic wave by the mobile phone shield, thereby achieving the shielding effect. However, depending on the circuit and layout, the tendency of the shielding cover is also different. If you need to know more about the shielding cover, you are welcome to call