An Ultrawideband Low-Loss Reconfigurable Metasurface Element With 1-Bit Resolution

In this letter, an ultrawideband and low-loss reconfigurable reflective metasurface element (RMSE) with 1-bit resolution is proposed. The design integrates a PIN diode with the cross-bow-tie patch to achieve 1-bit phase shift (180° ± 20°) from 6.75 to 11.25 GHz (50% relative bandwidth) using wideband techniques such as the gradient patch and parasitic shunting structure. The parasitic shunting structure significantly reduces the current flowing through the PIN diode, effectively minimizing element loss. Consequently, the proposed design achieves both an ultrawide operating bandwidth and low-loss performance. The physical mechanism is elucidated, and experiments are conducted. The experimental results align closely with simulations, validating the design's efficacy.