Study on open and short end helical antennas with capacitor in series of wireless power transfer using magnetic resonant couplings

In the technology of wireless power transfer, electromagnetic coupling using resonance can transfer across a large air gap without losing its high efficiency and power. In this technology, the role of antennas is very important. In this paper, magnetic resonant coupling using helical antennas is proposed. The helical antennas are two types- one is open end and the other is short end helical antennas and specifications of these antennas were studied which is related to the efficiency of power transfer wirelessly. The capacitor is installed to antennas in series and parallel is studied. High efficiency power transfer is possible when resonance is in series. The short end helical antennas with a capacitor in series make series resonance which makes resonance frequencies lower than open end helical antennas.