Dual-band dual-circular polarized beam-steering metasurface based on digital coding for intelligent IoV communication

A novel 1 bit dual-band dual-CP programmable folded metasurface (PFM) with dynamic beam steering capability is proposed for vehicle communications. The proposed PFM consists of a pair of functional metasurface antennas arranged on the top and bottom layers. Based on an analysis of the polarization twisting mechanism, a programmable polarization conversion metasurface (PPCM) of bottom layer is introduced. This distinctive unit cells design enables the realization of two electrically controlled states in which the reflected electric fields exhibit a phase difference of π. The dual-linear-to-circular polarization converter (DLCPC) of top layer is engineered to emit right-hand circularly polarized waves in the low-frequency band, while emitting left-hand circularly polarized waves in the high-frequency band. For demonstration, the proposed PFM is fabricated and measured. By controlling the on/off switching arrangement of the PIN through field programmable gate array (FPGA) and control circuit modules, a discrete phase distribution is achieved, enabling beam scanning from 0° to 50°. Numerical results illustrate a peak gain of 17.47 dBi and 19.7 dBi at 9.5 GHz and 13.5 GHz, respectively. Additionally, the 3-dB bandwidths are 10.4 % for the low frequency and 5.2 % for the high frequency, highlighting the potential of the proposed array for Internet of Vehicles (IoV) sensing and communications applications.