What is the working principle of wireless power transmission?

Answer 1

The working principle behind wireless power transmission is electromagnetic induction. Let's look at it. We need a power source and a transmitting antenna, and also a receiving antenna to which we can connect the thing to be powered (the electrical load, or just the load). The power source will deliver a high power signal to the antenna. This will create an electrostatic field around the antenna that changes as the signal to it changes. This will create electromagnetic waves that will travel out from the antenna and through the air. The receiving antenna will be in the path of these waves, and the waves will pass by it and "sweep" it with their moving electromagnetic fields. This will induce a signal in the receiving antenna proportional to the energy that the antenna captures. This signal will cause current flow that will power the load. The problem with this system is that it is challenging to "direct" and "confine" the transmitted signal to optimize how much of it gets to the receiving antenna. Additionally, distance causes loss, and there will be a lot of loss over longer distances. The more the distance the signal travels, the much more the loss. But the system works to a limited degree. Links can be found below.

Answer 2

Resonance. The power transmitter and the receiver are on the same frequency. The powered field has a coil ( it can be capacitor plates) that resonates at 6.4 megahertz (MHz). The coil two meters away is also tuned to 6.4 MHz. It resonates. Not like sending and receiving a signal. It is a field effect that works over a short distance with 60% efficiency.