An unequally spaced array antenna for mobile base stations

Typical electrical characteristics of base station antennas are low sidelobe levels and electrical beam tilt capabilities. Previously (1999) we studied a base station antenna of an equally spaced array configuration which can achieve low sidelobe characteristics and electrical beam tilt in 800 MHz to 2000 MHz. In 1500 MHz and 2000 MHz bands, many grating lobes appeared in the case of electrical beam tilt. This paper shows that suppression of grating lobes can be achieved in 1500 MHz and 2000 MHz bands by employing an unequally spaced array antenna configuration.