Dual-Band 2 × 1 Monopole Antenna Array and Its MIMO Configuration for WiMAX, Sub-6 GHz, and Sub-7 GHz Applications

Abstract

This study introduces a cost-effective monopole antenna array and its MIMO configuration. The single element consists of a rectangular patch monopole featuring five circular slots at the center, accompanied by two thin slots at the top, offering a wide bandwidth (2–7.62 GHz) and a peak gain of 3.8 dBi. For gain improvement, a 2 × 1 antenna array is demonstrated. This antenna array exhibits dual-band behavior; spans from 2 to 3.71 GHz and from 5.9 to 7.54 GHz; covers the 2.5 GHz band (2.3–2.7 GHz), a significant portion of the n78 band (3.3–3.71 GHz), and the n96 band (5.925–7.125 GHz); and is assigned to WiMAX, sub-6 GHz, and sub-7 GHz applications, respectively. The antenna array achieves a peak gain of 6.47 dBi. Lastly, a two-element MIMO configuration derived from the 2 × 1 array is designed. Implementing a defected ground structure (DGS) on the ground plane plays a crucial role in enhancing the isolation from 7 dB to 20 dB. The presented MIMO antenna covers the desired frequency bands of 2.5 GHz, n78, and n96 with a peak gain of 7.5 dBi and high radiation efficiency (<99%), which qualifies it for WiMAX, sub-6 GHz, and sub-7 GHz applications.