A circularly-polarized microstrip grid array antenna for 60 GHz radios

A circularly-polarized (CP) microstrip (MS) grid array antenna (GAA) is designed for 60 GHz radios on Ferro A6M LTCC. The profile of the antenna is 17 mm square by 0.5 mm thick. Instead of designing a large array, the radiating array is divided into four sub-arrays to achieve high radiation efficiency. Method to improve the antenna´s axial ratio bandwidth is developed. Simulation results in Ansoft HFSS show that its axial ratio bandwidth is from 56 GHz - 63 GHz, impedance bandwidth from 55.5 GHz - 65 GHz, highest gain 15.5 dBi at 60 GHz and radiation bandwidth from 56.8 GHz - 66.3 GHz with vertical patterns from 57 GHz - 63 GHz. It is a preferable choice for 60 GHz radios.