A Compact Dual-Band Dual-Circularly Polarized SIW Cavity-Backed Antenna Array for Millimeter-Wave Applications

A compact millimeter-wave (mm-Wave) dual-band dual-circularly polarized (CP) antenna based on substrate integrated waveguide (SIW) cavity-backed structure is proposed in this letter. By introducing the square aperture with two symmetric perturbation notches on the SIW cavity, right-hand CP (RHCP) can be generated at the low frequency band. On this basis, the dumbbell-shaped patch is placed inside the square aperture to generate left-hand CP (LHCP) at the high frequency band. To optimize the impedance matching and adjust resonant frequency, stacked parasitic patches are adopted. In addition, the two shorted vias are introduced to realize the independent tuning of high frequency band. The measured results show that the array achieves the impedance bandwidths of 7.3% and 7.5%, AR bandwidths of 2.8% and 2.6%, with gains of 18.2 and 18.5 dBic at 28 and 38 GHz, respectively. The proposed array will be a potential candidate component for 5G mm-Wave full-duplex wireless communication systems.