Polarisation diverse multiple input–multiple output antenna with enhanced isolation

In this article, two-element monopole multiple input-multiple output (MIMO) antenna with polarisation diversity for 4G and other applications has been presented. The designed antenna covers 16% (1701-2001 MHz) of bandwidth around the design frequency (1850 MHz) which includes both DCS-1800 and DCS-1900 bands. The two antennas are placed orthogonally and symmetrically with edge-to-edge spacing of 5.5 mm (λ₀/30). With the placement of interconnected swastika-shaped resonator between the two monopole antennas, there is an isolation enhancement of 60 dB thus reducing the envelope correlation coefficient value ranging from 0.016 to 6.12 × 10^-10 and improving the diversity gain ranging from 9.9 to 10 dB within the -10 dB bandwidth. A prototype has been fabricated and validated using measurements.