As wireless networks transition into higher frequency bands, wireless signals tend to have smaller ranges and the inability to penetrate objects as well. An intelligent reflecting surface (IRS) can offer improved coverage in wireless networks by redirecting wireless signals around objects that obstruct the signal’s line-of-sight path. IRSs are comprised of an array of unit cells which enables the redirection of an incoming signal to an anomalous angle due to a phase gradient formed across the surface. Traditional IRSs use PIN or varactor diodes to change the reflection phase response of a unit cell. However, liquid metal is an alternative method to control the reconfigurability of the reflective element. By changing the shape and size of the liquid metal reflective element, the unit cell’s phase can vary. In this work, we develop a testing setup for evaluating IRSs and metasurfaces to ensure that they are performing as expected. To evaluate these surfaces, we compare the measured and simulated bistatic radar cross section (RCS). We explore the effects of the propagation environment and a processing technique called time-gating to achieve accurate measurements.

Keith Maki is an M.S. candidate in Electrical Engineering at the University of Hawaii at Manoa. He received a B.S. in Electrical Engineering from the University of Hawaii at Manoa in 2022. His current research focuses on liquid metal and its application in intelligent reflecting surfaces (IRS).