Small and medium companies should design WIFI modules in this way-Company news

There are so many types of antennas. Specific parameters are discussed in detail. In addition to the first type of external antenna, the others are built in antennas. The location of the built-in antenna is related to the structure. Metal will shield the WIFI signal, if it is a metal shell, the WIFI antenna signal is very difficult to radiate from the shell, so the strength does not choose the metal shell or the silver coating. And the internal PCB board will block the WIFI signal. In fact, the transmission power of WIFI is now basically fixed at 100 mW, which is stipulated by the Radio Authority that the maximum transmission power can not exceed 100 mW. All equipment that can be bought is basically certified without commission. Good performance depends on antenna matching, antenna and antenna position.

So what do we have to do in the design?

The performance of the antenna. We have to test the performance of the antenna. Many times we can refer to the various DATASHEET supplied by the antenna manufacturer. However, we should pay attention to the parameters provided by various manufacturers, whether there are any missing items, or to test them again to see if this is the effect.

The effect of the antenna in the whole machine. Test the antenna's Bobbi in the assembled machine. For antenna matching circuits, we usually leave a PI network at the end of the antenna feeder to match the antenna ends. This PI network can effectively improve the antenna in the machine in Bobbi situation.

The position of the antenna. In this case, I will discuss only the antennas with built-in modifications, without discussing the external and onboard antennas. Our general routing and machine are on a horizontal plane. Our regular demand is higher antenna gain in horizontal direction. Therefore, the attitude of the antenna should be determined according to the gain direction of the antenna, but only the attitude is adjusted, and the position is not determined. Also observe a principle that the antenna must be at least 1cm from the PCB board. Finally determine whether there is a high-speed signal line near the antenna, inductance and so on. The antenna tends to be placed in the corner so that its radiation range is greater.

So the whole machine has completed the layout of the antenna, we need to do all the channels, in all directions, the ability to test the wall, if it does not meet the design requirements, replace the antenna, replace the position, and then test the results.