A stretchable frequency reconfigurable antenna controlled by compressive buckling for W-band applications.

Reconfigurable antennas have attracted significant interest because of their ability to dynamically adjust radiation properties, such as operating frequencies, thereby managing the congested frequency spectrum efficiently and minimizing crosstalk. However, existing approaches utilizing switches or advanced materials are limited by their discrete tunability, high static power consumption, or material degradation for long-term usage. In this study, we present a W-band frequency reconfigurable antenna that undergoes a geometric transformation from a two-dimensional (2D) precursor, selectively bonded to a prestretched elastomeric substrate, into a desired 3D layout through controlled compressive buckling. Modeling the buckling process using combined mechanics-electromagnetic finite element analysis (FEA) allows for the rational design of the antenna with desired strains applied to the substrate. By releasing the substrate at varying compression ratios, the antenna reshapes into different 3D configurations, enabling continuous frequency reconfigurability. Simulation and experimental results demonstrate that the antenna's resonant frequency can be tuned from 77 GHz in its 2D state to 94 GHz in its 3D state in a folded-dipole-like design.