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An adaptively smart wireless power transfer (WPT) system is proposed by using a 2-bit programmable metasurface (PMS), in which an in-door dynamic charging application scenario is described and near-field focused (NFF) technique is adopted to transmit wireless powers. Theoretical analyses of NFF PMS are presented to illustrate its WPT capabilities. To implement dynamic WPTs, digital phase-shift quantization of PMS element is investigated, indicating that 2-bit quantization scheme is a preferred solution. A 2-bit 1212 PMS operating at 5.8GHz is designed, fabricated and tested. High-power focal spots that can be regulated to focus at different near-field positions are measured in an anechoic chamber. We conduct multiple WPT experiments by using the 2-bit PMS as the transmitter and a 44 microstrip array antenna as the receiver. Experimental results show that the proposed 2-bit PMS can continuously transmit the wireless powers to the receiver even though the target is moving, and the WPT efficiency is maintained over 9.1%, which has about 16.3 dB improvement at the end of the trajectory compared to the fixed NFF beam. This work is one of attempts to thoroughly examine the possibility of the dynamic WPTs using PMS, offering a brand-new manner for the adaptively smart WPT systems.

In this letter, we present a holographic metasurface (HMS) based on an orthogonally discrete unit-cell. The proposed unit-cell possesses discrete surface impedance tuning abilities in two orthogonal directions, providing flexible beam formation as a scalar unit-cell and polarization control as a tensor unit-cell. Operation principle and design formulas for generating independently linearly polarized beams and circularly polarized beams using the orthogonal components are concluded. Two example antennas utilizing this HMS are measured to demonstrate the beam formation and polarization control abilities at 11.0 GHz. The first example antenna generates dual beams with independently linear polarizations whereas the second example antenna generates dual beams with independently circular polarizations. Our letter indicates that there exists a middle type of HMS between scalar and tensor HMSs.

This paper presents a dual-polarized reconfigurable antenna loading electronically steerable parasitic patches. The proposed dual-polarized antenna is surrounded by four parasitic patches each of which is mounted by two varactor diodes on the ground. By tuning the varactors, continuous two-dimensional beam-steering can be achieved for each of the polarization. A prototype of the proposed antenna is fabricated and measured. Excellent agreement between the simulated and measured results is observed. It is observed that the maximum beam-scanning angles in E-plane and H-plane are greater than ±25∘, which is suitable for 5G base station applications.