Beam-Switchable Digital Conformal Array With Metasurface Phase Compensation

Abstract

This article presents a novel digitally reconfigurable conformal array using the multimode control and metasurface phase compensation. The digital conformal array consists of a 1-bit multimode radiator, metasurfaces, and switch designs. By manipulating the field distributions of the transmission line (TL), a miniaturized multimode radiator is explored. Next, a low-cost 1-bit planar digital array without any feeding networks is proposed by coding the 0°/180° phase states of each mode/element. To match the circular/cylindrical/spherical scenarios, the planar digital array evolves into a conformal format. Here, to further lower the complexity and cost, the spatial phase difference of the digital conformal array is cleverly compensated by utilizing a metasurface layer rather than conventional phase-delay-line designs. By controlling the 1-bit phase states of each element, the radiation aperture of the digital conformal array is represented as a “0/1” binary sequence, which leads to an RIS-like multibeam switching capability. Moreover, by introducing the initial phase, a new 1-bit digital array with a single-beam steering capability is extended to further explore its application potential. To validate the concept, a four-element 1-bit digital conformal array was fabricated and measured. The digital conformal array could achieve a −10 dB impedance bandwidth of 4.74–5.12 GHz (7.7%) and a peak gain of 11.0 dBi, which makes it a good candidate for intelligent wireless communication and detection applications.