An Ultrawideband Low-Scattering Antenna With Hybrid-Mechanism Microfluidic Metasurface

This article introduces a novel low-scattering antenna design approach that employs a hybrid mechanism based on liquid-based metasurface (MS). The proposed design leverages this hybrid mechanism to achieve superior performance. A checkerboard structure loaded with microfluid produces phase cancellation and absorption at two different frequencies, respectively, which reduces the radar cross section (RCS) by more than 4 dB over an ultrawideband of 8–61 GHz, covering the X-, Ku-, K-, Ka-, U-, and E-bands. A high-gain directional antenna is achieved by exciting the checkerboard with a slot array. This antenna has a very low profile of $0.097\lambda _{0}$ and operates in the 7.3–7.6 GHz band, which is promising for wireless local area network (WLAN) applications. In this article, two mechanisms of the array antenna are analyzed in detail. The proposed method of a liquid-based MS combined with a slot coupling feeding method also provides an important reference for the design of low-scattering antennas.