Gridded parasitic patch stacked microstrip antenna with beam shift capability for 60GHz band

A microstrip antenna design is introduced in which aperture coupled rectangular microstrip patch is coupled electromagnetically with a parasitic gridded rectangular patch placed above. The gridded patch consists of nine identical rectangular parts separated by a distance which is much smaller than a free space wavelength for a central frequency. The antenna is designed to operate in the 60GHz band and is fabricated on a conventional PTFE (polytetrafluoroethylene) thin substrate. Different published arrangements for parasitic patches are studied. For the same substrate and central frequency the proposed antenna has improved return loss bandwidth and gain bandwidth. Measurement results are in good agreement with simulation. Measured 10 dB return loss bandwidth is from 54 GHz up to 67 GHz. It fully covers the unlicensed band around 60 GHz. The measured antenna realized gain at 60 GHz is close to 8 dB, while the simulated antenna radiation efficiency is 85%. A beam shifting method is proposed for this antenna structure by connecting adjacent outside parts in the gridded patch. The designed antenna is suitable for a high speed wireless communication system in particular for a user terminal in a fifth generation (5G) cellular network.