Dynamic Realization of Broadband Microwave Illusion Using Programmable Metasurfaces

ABSTRACT Achieving dynamic and broadband microwave illusion remains highly challenging for stealth platforms. Here, a hybrid‐phase synthesis strategy that combines structural control with voltage tuning is proposed for programmable metasurfaces embedded with varactors. An active meta‐atom with resonantly coupled metallic “H” structure and parasitic patches is designed to provide large phase coverage, while eight meta‐atoms with different structural parameters are selected through gradient‐descent optimization. Required reverse‐biased voltages are then determined frequency by frequency using a root‐finding algorithm, enabling accurate phase restoration and broadband wavefront reconstruction through FPGA control. To validate the concept, a programmable illusion metadevice is fabricated by wrapping the metasurfaces over a 3D triangular platform with a tilt angle of 30°. Simulated and measured results demonstrate that the device reconstructs scattering wavefronts within 1.9–3.1 GHz, corresponding to a fractional bandwidth of 48%, for multiple virtual objects under different incidence conditions. In addition, the system exhibits a switching response time of approximately 71 µs and a total power consumption of 6.13 W, highlighting its potential for practical broadband microwave illusion applications.