Mutual Coupling in Dynamic Metasurface Antennas: Foe, but Also Friend

Dynamic metasurface antennas (DMAs), surfaces patterned with reconfigurable metamaterial elements (meta-atoms) that couple waves from waveguides or cavities to free space, are a promising technology to realize 6G wireless base stations and access points with low cost and power consumption. Mutual coupling (MC) between the DMA's meta-atoms results in a non-linear dependence of the radiation pattern on the DMA configuration, significantly complicating modeling and optimization. Therefore, MC between meta-atoms has to date been considered a vexing nuance that is frequently neglected in theoretical studies and deliberately mitigated in experimental prototypes. Here, we demonstrate the overlooked property of this MC to boost the control over the DMA's radiation pattern. Based on a physics-compliant DMA model, we demonstrate that the radiation pattern's sensitivity to the DMA configuration significantly depends on the MC strength. We further evidence how the enhanced sensitivity under strong MC translates into a higher fidelity in radiation pattern synthesis, benefiting applications ranging from dynamic beamforming to end-to-end optimized integrated sensing and computing. Our insights suggest that DMA design should be fundamentally rethought to embrace the benefits of MC. We also discuss ensuing future research directions related to the frugal characterization of DMAs based on compact physics-compliant models.