There are more and more wireless charging terminals, but there are not many batch shipments. The reason is that many transceivers are unfamiliar with these design companies. Today, smart wireless charging companies share the types and characteristics of wireless charging coils. Help everyone! This type of charging coil is essentially an antenna with many indicators such as impedance, frequency, etc. There are two types of transmission and reception. There are close distances and long distances, but considering electromagnetic radiation, it is suitable for close range (within 2-3mm), and there are more manufacturers to support. Second: the transmitting and receiving coils must have the same resonant frequency and be used in pairs, that is, the QI standard is a wide frequency band (110Khz-205Khz). The terminal is different, the transmitting coil antenna and the receiving process are different. If the environment of the transmitting antenna is installed, it is possible to use a thick copper wire and a multi-layer winding, that is to say, the thickness of the antenna is not particular. However, the receiving antenna, considering the installation position, must be ultra-thin. Especially for smartphones, there is only space for mounting inside the case. The receiving terminal looks at the type, the laptop is 120W, and the terminal such as the mobile phone is 5W.
The wireless charging coil antenna in the mobile phone is best placed inside the phone case. Because the charging gap is large, the charging efficiency will be low. One micron corresponds to a current loss of about 0.1 mA, and 1000 micrometers (1 mm) will lose more than 100 milliamperes. Be sure to add a magnetic isolation material behind the wireless charging coil in the mobile phone, which is divided into inorganic magnetic materials. For example PC44 and organic series materials. Inorganic, is a sintering process, easy to break, not suitable for sticking to the phone case, because it is easy to damage, and a flat piece of 40mm in diameter is installed on the curved shell, which is not suitable. Therefore, this type of inorganic magnetic material can only find space on the circuit board. The organic magnetic material can be bent, and there are positioning holes at the four corners, and the plastic positioning post can be extended inside the outer casing of the mobile phone, and is stuck in the positioning hole, so that the installation is good. The antenna determines the number of turns, etc., and the antenna manufacturer needs to take the terminal to test and debug the optimal parameters, so that the charging efficiency is high. This is the same process as doing a built-in antenna for a mobile phone.