High gain dual-polarised pentagonal microstrip antenna for wireless communications

Abstract

In this paper we propose a dual polarised pentagonal microstrip antenna for massive MIMO-base station to operate at 2.4 GHz WLAN band (IEEE 802.11 b/g/n/ax). The various researchers have used antenna array with different feeds for the massive MIMO BS to obtain the desired gain with required impedance bandwidth. However, this proposed work contradicts with existing method by using a single novel radiating element with suspended substrate to achieve the desired gain and required impedance bandwidth. The circular polarisation is achieved by using two coaxial-probe feeds. The main focus of research is on the selection of proper shape of the radiating element for Massive MIMO BS. The proposed antenna is successfully simulated using HFSS 13.0, fabricated on a FR-4 substrate and measured. The proposed antenna exhibits a much higher gain of 6.17 dB, improved impedance bandwidth of 171.9 MHz (return loss, S11=−10 dB), the axial ratio (AR) is 1.78 dB (< 3 dB), the patch area of 1,775 mm2, and also yields return loss better than −15 dB around the centre frequency of 2.45 GHz. The measured characteristics of the antenna are in good agreement with the simulated results.