Engineers from the University of Aalto developed the improved method of long-term wireless charging. Having improved the interaction between transmitting and receiving antennas and using the phenomenon of “suppression of radiation”, they have expanded our theoretical understanding of wireless energy transmission outside traditional inductive methods.
Effectiveness at large distances
Charging at short distances, for example, through induction pillows, uses magnetic fields to transmit energy with high efficiency. However, at large distances, the effectiveness decreases sharply. New studies have shown that high efficiency can remain at long distances, suppressing the radiation resistance of the loop antennas, which transmit and accept energy.
Previously, the same laboratory has created an omnidirectional wireless charging system that allows you to charge devices in any position. Now the researchers have presented a new dynamic theory of wireless charging, which considers both close and distant transmission conditions. They showed that high transmission efficiency, more than 80%, can be achieved at distances about five times the size of the antenna.
“We wanted to effectively transmit energy, taking into account radiation losses at large distances,” says the lead author to us Ha -Wan. “It turned out that with equal amplitudes and opposite phases of currents in the loop antennas, we can compensate for radiation losses, thereby increasing efficiency.”
A universal approach to the assessment of wireless energy transmission
Scientists have developed a method for analyzing any system of wireless energy transmission, whether it is mathematical or experimental. This allows you to more carefully evaluate the effectiveness of energy transmission at different distances. Studies of Ha-Wana and his colleagues can take into account obstacles that can interfere with charging.
“We tried to find out the optimal configuration for wireless energy transfer,” says Ha -Wan. “With our approach, we can increase the transmission distance outside of traditional wireless charging systems, while maintaining high efficiency.”