Frequency-Selective Beamforming with Dynamic Metasurface Antennas

Dynamic metasurface antennas (DMAs) enable beamforming through low-power components that reconfigure each radiating element. Previous studies on a single user multiple-input-single-output (MISO) system with transmit DMA focused on maximizing beamforming gain in narrowband scenarios. In this paper, we analyze the beamforming performance of DMAs in wideband scenarios. By leveraging DMA's frequency reconfigurability, our proposed approach dynamically adjusts both the transmission frequency and element configuration, achieving a higher beamforming gain than the narrowband method. We also propose the optimal waveguide refractive index and DMA element spacing to obtain an equal beamforming gain as the power hungry true-time-delay (TTD) architecture in the desired angular range. We evaluate the achievable rate performance and show that the rate approaches that of TTD when the DMA tuning range increases.