Metamaterial-Based Pattern-Switchable Linear Array for 2-D Discrete Beam-Scanning Using Hybrid Digital Coding Method

A new low-cost, pattern-switchable, metamaterial-inspired, dielectric resonator (DR) 1-D linear array for 2-D beam-steering is presented by using a hybrid digital coding method. By loading the metasurface on the DR, a low-profile DR radiator is developed. To realize both phase and pattern digital coding, a beam-switching metasurface-loaded 1 bit DR antenna is explored by using a symmetrical feeding scheme and a Yagi-like endfire radiation mechanism. The novel hybrid digital coding method is realized by using p-i-n diodes to co-control the phase (1 bit, 0°/180°) and radiation states (three-beam). Based on the hybrid digital coding method, the developed 1-D linear array creatively achieves low-cost quasi-2-D discrete beam scanning. The pattern reconfiguration technique contributes to the E-plane beam scanning, while the H-plane beam steering is attributed to the phase digital coding sequence. To validate this working mechanism, a four-element linear array is implemented and tested. The realized overlapped −10 dB impedance bandwidth is about 17.6% (covering LTE B42/43 bands), and the realized peak gain is 9.05 dBi. By controlling the switch states of 16 p-i-n diodes, the proposed four-element linear array achieves digital 2-D beam steering (12 beams). The presented antenna features a miniaturized size, wideband, low cost, and good 2-D beam-steering capacity. It provides a new and feasible solution for low-cost 2-D beam scanning, demonstrating a good application potential for intelligent communication systems and low-cost arrays.