Efficient wireless power transfer using underground relay coils

Underground Wireless Sensor Network (UWSN) is a newly emerging technology that is capable of replacing existing traditional wired connections. Research has proved that magnetic induction based communication performs better than electromagnetic wave communication, especially in the dynamic underground environment. Currently, data recorders are being used to collect the data from underground sensors. Data recorders have a few disadvantages such as the inability to produce data on time and the difficulty to deploy them. Many problems related to data recorders can be solved using UWSN´s magnetic induction technique. One of the main challenges associated with the UWSN is the lack of efficient power transfer to underground sensors as the distance between the transmitter and the receiver coils increases. This paper introduces a unique technique where relay resonators are used between the transmitter and the receiver coils to increase the efficiency for charging sensors which are present underground. Experimental results that prove the presence of relay coils for efficient power transfer are presented.