Shorting pins-based triple band circularly polarized modified monopole compact dual-port MIMO antenna for sub-6 GHz wireless applications

A shorting pin-based, compact two-port MIMO, modified monopole antenna with high isolation, circular polarization (CP) and pattern diversity is presented for 5G wireless applications. The antenna shows -10 dB impedance bandwidth of 550 MHz (0.95 GHz-1.50 GHz), 320 MHz (3.35 GHz-3.67 GHz), and 410 MHz (5.01 GHz-5.42 GHz) with excellent isolation of over -20 dB within all three operating bands. The antenna is circularly polarized and provides an axial ratio bandwidth (ARBW) of 100 MHz, 300 MHz, and 150 MHz centered at 1.2 GHz, 3.5 GHz, and 5.2 GHz, respectively. To maintain the compact size at L -Band (along with two other bands) and high isolation, three modified monopoles are extended on the bottom layer of the antenna through shorting pins. An in-built isolator is integrated on its ground plane to suppress the mutual coupling between both ports of the proposed MIMO antenna. The antenna is fabricated on Rogers RO4350B substrate of an overall dimension of 34 x 38 x 1.52 mm3 (0.20 lambda 0 x 0.22 lambda 0 x 0.009 lambda 0). The proposed antenna exhibits pattern diversity. The antenna's performance is also evaluated for MIMO system criteria by analyzing various diversity parameters. The proposed antenna is easy to fabricate and can be integrated with other MMIC components.