Highly Integrated Reconfigurable Shared-Aperture EM Surface with Multifunctionality in Transmission, Reflection and Absorption

In this article, we present a highly integrated reconfigurable electromagnetic (EM) surface capable of real-time control of EM wavefronts in full-space. This design allows for dynamic switching between transmission, reflection, and absorption modes within a shared aperture. The unit cell features a multi-layered structure comprising four positive-intrinsic-negative (PIN) diodes and two co-polarized resonant patches connected via a central metal via. When the two PIN diodes of the receiving patch are activated, the resistor integrated in the matched branches efficiently absorbs EM waves. In contrast, switching off these diodes enables precise 1-bit phase resolution for both transmitted and reflected waves, achieved through the four states of two diodes on the transmitting patch. Furthermore, this paper demonstrates the ability to generate bidirectional beams through geometric aperture division. A 16 × 16-unit-cell prototype is fabricated, with experimental and simulated results showing good agreement, validating its ability to control wavefront in full-space. With its programmable nature, the novel EM surface holds tremendous potential in stealth technology, EM imaging systems, intelligent radomes, and the advancement of next-generation wireless communications.