Suspended 60 GHz phased array antenna with high efficiency

This paper presents 5×5 aperture coupled microstrip patch phased array antenna with suspended radiating elements operating at 60 GHz. A novel microfabrication technique enables separation of radiating elements from a lossy substrate. It was found that suspended elements improve efficiency and scanning range without sacrificing gain of the array by decreasing trapped energy at air dielectric boundary (surface waves). The array has a bandwidth of 7.5 GHz (12.5%) and capable of scanning ±60° in both E and H planes. Total array efficiency is calculated to be >90%. Simulation results show 18.6 dB gain with -12 dB sidelobe level at boresight. Furthermore, array gain is 15 dB and 14.5 dB when scanning ±60° in E and H-planes, respectively.