A Transparent Antenna Using Metal Mesh for UWB MIMO Applications

This article presents a transparent ultrawideband (UWB) multiple-input–multiple-output (MIMO) antenna based on a wired metal mesh (MM) structure. Transparent antennas (TAs) can be integrated into various building materials with little visual impact to facilitate flexible massive indoor wireless device deployment. The proposed antenna achieves 77% transparency by hollowing out both metal and substrates into a mesh shape, while maintaining more than 83% radiation efficiency. The MIMO antenna consists of four elements, each being a coplanar waveguide (CPW)-fed UWB monopole and adjacent elements being placed orthogonally to produce dual polarization. The operating band of the MIMO antenna spans over 3.2–11.2 GHz. A parasitic decoupling structure aligned with the mesh grid is designed to enhance the isolation between MIMO elements without degrading the transparency. Within the entire operating band, the isolation between any two elements is more than 20 dB. The peak gain varies from 3.3 to 7.2 dBi within the bandwidth. The envelope correlation coefficient (ECC) is less than 0.004. The channel capacity and time domain response are analyzed. The antenna can be easily fabricated by conventional printed circuit board (PCB) and laser cutting techniques at a low cost.