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A varactor-based reconfigurable multifunctional metasurface capable of simultaneous beam steering, polarization conversion and phase offset is proposed in this communication. The unit cell is designed to naturally decompose the incident waves into two equal-amplitude orthogonal linear components, and by integrating varactors, the reflection phase of the field components can be engineered from −180° to 180°. Taking advantage of the infinite states of the varactors, this design integrates a new function, the phase offset. After simulation validation of its capability, a four-layer 7 by 6 unit 1-D prototype is fabricated as a printed circuit board. It is experimentally demonstrated that it switches between X/Y and circular polarization with more than 0.9 polarization conversion rate (PCR), while reaching ±45° steering and ±180° phase offset.

In this letter, we quantitatively analyze the mechanism of two coils working in the near-field/far-field hybrid zone. In particular, we propose to separate the coupling in terms of static and radiative, rather than the ambiguous near or far field. The results of our impedance matrix model show that the domination of the two mechanisms depends on both the antenna geometry and the antenna arrangement. We demonstrate how one may take advantage of the hybrid coupling mechanism to acquire maximized gain and to broaden the channel bandwidth.