Near-field focused planar transmitarray with low profile design for microwave power transmission

Abstract

This paper proposes a near-field focused (NFF) planar transmitarray with low profile operating in the C-band. A frequency selective surface (FSS) unit cell with a profile of only 0.15λ is designed by combining generalised scattering theory with full-wave simulations. To achieve better focusing, the transmission phase of the central unit cell of the transmitarray is adjusted to 90^°. The focusing relative bandwidth is 13.7% at a centre frequency of 5.8GHz, which enables a good focusing effect to be achieved. Meanwhile, this paper evaluates the microwave power received at the receiver when the proposed transmitarray used in MPT system. The measured results show that loading the proposed transmitarray can improve the received power up to 510%. Futhermore, in the range of 220-660mm from the transmitarray, the received power can be increased to more than 300%.