Dual-linear-polarization substrate integrated waveguide patch antenna array

This article presents a 37 GHz compact patch antenna array which can generate dual-linear-polarization (LP) from a single radiating aperture for mm-wave applications. The antenna adopts dual-layer structure to achieve miniaturization and also to design the feeding network. The substrate integrated waveguide (SIW) feeding network is built in the bottom layer. On the top layer, multi-strip +/- 45 degrees polarized series-fed patch subarrays are fabricated. Patches with variable width and two eight-way unequal power dividers are employed to suppress the sidelobe level (SLL) in two planes. A 90 degrees 3 dB coupler with a 90 degrees electric length of SIW is adopted to realize same phase and opposite phase. Thus, two polarized waves, namely vertical linear polarized wave (VLP) and horizontal linear polarized wave (HLP) can be generated. Finally, a prototype SIW patch antenna array is fabricated. The antenna gain is about 24-25 dBi for both VLP and HLP and SLL is under -12 dB in the frequency range of 36.5-37.5 GHz.