Cavity-excited impedance surfaces for full-space beam steering via combination of integral equations and baffles

Herein, we propose and numerically validate two-dimensional cavity-excited impedance surfaces for full-space beam steering, facilitated by an efficient design framework that combines the idea of baffles and an integral-equation-based formulation. The proposed system directly transforms cavity modes excited by integrated sources, thus achieving a low profile. In contrast to traditional metasurface designs, which often overlook mutual coupling between unit cells, the proposed architecture and its design framework ensure proper consideration of mutual coupling. Specifically, baffles are strategically placed within the 2D cavity to suppress mutual coupling in one direction, while the integral-equation-based formulation manages coupling in the orthogonal direction. Based on the method of moments, the induced surface and volumetric current densities throughout the structure are optimized to produce the desired far-field patterns. In particular, various beam-steering scenarios are considered for ${\ensuremath{\theta}}_{o}\ensuremath{\in}{{0}^{\ensuremath{\circ}},{25}^{\ensuremath{\circ}},{50}^{\ensuremath{\circ}}}$ and ${\ensuremath{\phi}}_{o}\ensuremath{\in}{{0}^{\ensuremath{\circ}},{45}^{\ensuremath{\circ}},{90}^{\ensuremath{\circ}}}$. Full-wave simulation results show that the system achieves directivities comparable to perfect apertures. Dual-beam steering, which requires independent control over both the amplitude and phase of the aperture fields, is also explored. The proposed architecture and its design framework lend themselves to a wide range of applications in which precise, full-space beam steering and compact design are critical, spanning next-generation communication systems, satellite platforms, radar technologies, and beyond.