A compact four elements UWB MIMO antenna with on‐demand WLAN rejection

Abstract

ABSTRACT This article presents a four elements frequency reconfigurable ultrawideband (UWB) multiple‐input‐multiple‐output (MIMO) design, capable of rejecting on‐demand WLAN band ranging from 4.8 to 6.2 GHz. The proposed design consists of two U‐shaped monopole UWB radiators and two circular slotted‐monopole radiators. These monopole radiators are placed orthogonally with respect to each other to exploit polarization diversity, whereas the PIN diodes are used to connect the band‐stop design with the ground plane to introduce the on‐demand band rejection feature. An isolation of better than 17 dB between the four UWB‐MIMO elements is achieved in the 2.7–12 GHz frequency range for the both PIN diodes biased and unbiased states. The simulations and measurements results showed good agreement over the band of interest. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:270–276, 2016