Design of immensely isolated 2×2 MIMO antenna for dual-polarized triple-frequency applications

Abstract

This paper represents the design and implementation of dual-polarized-triple-frequency 2×2 Multiple-Input-Multiple-Output (MIMO) antenna with extremely high isolation capabilities having total dimensions of 50×155 mm2. Proposed antenna succeeds triple band frequency operations including GSM (IEEE-802.21), WiMAX (IEEE-802.16) and WLAN (IEEE-802.11n) bands of modern wireless communication system. Circular polarization has been hosted in WiMAX and WLAN bands with ≤ 3 dB axial ratio (AR) while GSM band obeys linear polarization; hence dual-polarized operation has been accomplished with the same geometry. Highly isolated structure has been investigated by means of inverted ground planes and integration of parasitic strips amongst the radiating antennas. Fabricated 2×2 MIMO antenna achieves triple band operations that is, GSM (1.78-1.82 GHz), WiMAX (3.3-3.7 GHz) and lower edge of WLAN (5.15-5.35 GHz) with S11, S22 ≤ -10 dB for aforementioned bands and attains S21 ≤ -42 dB isolations within electrifying ports. Designed antenna fulfills directional radiation patterns along E-plane and omnidirectional in H-plane with highest -49 dB cross polarization levels. Antenna has simulated on MOM based CADFEKO software. Simulated peak gain of 4 dBi has been acquired with 78% of peak efficiency. Designed 2×2 MIMO antenna has linear and constant group delay with superior time domain response for a Gaussian pulse.