Importance of antenna impedance matching

Impedance is an important parameter of the antenna, which is determined by the physical structure of the antenna, such as the shape, size, material, and environment of use. The impedance matching of the antenna is the process of matching both the impedance of the antenna and transmitting the source through tuning. So, why do you need to do antenna impedance matching?

When the antenna is working, the high-frequency signal is fed to the antenna, most of the energy is radiated from the antenna, and the other part is reflected back to the emission source, and forms a standing wave on the transmission path. When the transmitting source impedance is equal to the antenna impedance, that is impedance matching, the reflection is the smallest and the loss rate is also the smallest. If the impedance between the antenna and the emission source is matched, not only can the working range be increased, but also the power consumption of the wireless device can be reduced.

The impedance of the antenna is very complicated, including resistance and reactance, so the matching network must include both of them. That is to say, in addition to equal resistance components, reactance components must also be equal in magnitude and opposite in sign to form a conjugate matching network.