Compact MIMO Vivaldi Tapered Slot Antenna for UWB Systems with WLAN/WiMax Band-notched Features

Abstract

This manuscript presents a compact Multiple-Input Multiple-Output (MIMO) Ultra-Wideband (UWB) Vivaldi tapered slot antenna with dual band-notched characteristics. The proposed antenna has overall dimensions of 20 × 29.4 mm², and its design procedure and performance are comprehensively investigated. A detailed description of the antenna design evolution is provided. A stepped feed line is employed to enhance the impedance bandwidth for a reflection coefficient below -10 dB, while a meandered slot and an arc-shaped stub are incorporated to create notched bands at the WiMAX and WLAN frequencies, respectively. To improve the isolation between the MIMO antenna elements, a tuning fork-shaped slot is etched in the ground plane between the two ports. The measured results demonstrate that the proposed antenna operates over a wide bandwidth from 2.6 to 12 GHz, while effectively rejecting the 3.5 GHz and 5.6 GHz bands, corresponding to the WiMAX and WLAN bands, respectively. In addition, a minimum isolation of 18 dB is achieved across the operating band. Owing to its compact size, good MIMO diversity performance, and dual band-notched characteristics, the proposed antenna is a promising candidate for modern wireless communication systems and UWB applications.