A compact double-sided four-port printed antenna with pattern and polarization diversity for super-wideband applications

A compact, double-sided four-port printed antenna with pattern and polarization diversity performance is proposed for super-wideband (SWB) applications. The proposed printed antenna consists of microstrip line-fed corner truncated four identical square patches. One pair of patches is placed strategically on the top side of the substrate, and another pair is on the bottom side with rotational symmetry to realize a compact four-port antenna with higher port isolation (>25 dB) throughout the operating band along with pattern diversity. A half-circular slit is etched in the partial ground plane of all four antennas to achieve SWB (1-19.81 GHz) response. A meander-shaped decoupling structure is incorporated on both sides of the substrate to enhance the port isolation. T-shaped slots on the patch and corner truncations are conceived to achieve circular polarization (CP) across 5.15-5.83 GHz. The beauty of this structure lies in the easy switching between LHCP and RHCP by just controlling the port excitation. Moreover, the strategic placement of antenna elements produces bidirectional patterns with proper choice of port excitation. A good agreement is observed between the measured and simulation results.