Two‐element printed PIFA‐MIMO antenna system for WiMAX and WLAN applications

Abstract

In this study, a printed dual-band multiple-input multiple-output (MIMO) antenna is presented for Worldwide Interoperability for Microwave Access (WiMAX) and wireless local area network (WLAN) applications. Two symmetric printed inverted-F antennas (PIFAs) are considered here as radiators. One of the open-circuited radiating arms of the PIFA is loaded with a folded resonator to achieve dual-band characteristics. Two symmetric stepped `L'-shaped open ground slots have been introduced to enhance the isolation at the lower operating band. This also realises diagonal orthogonal radiation patterns of the antenna elements a results low correlation between them. Measurement reveals that the proposed MIMO antenna system has two 10 dB return loss bandwidths in the ranges of 2.6-3.08 and 5.48-6.12 GHz with isolation >21 dB over the operating bands. Respective gains are 2.5 and 3.48 dBi at the lower and upper resonant frequencies, respectively. Promising diversity performances are also investigated in terms of different MIMO parameters (total active reflection coefficient, envelope correlation coefficient, diversity gain, mean effective gain, and channel capacity loss), which are found within their acceptable range. Furthermore, the characteristics of the antenna have been investigated in the presence of a large ground plane, USB connector, and housing to ensure the applicability of the proposed antenna in handheld wireless devices.