Diversity antenna system with electrical tilt

摘要

A diversity antenna system with electrical tilt has two dual polarized, tilt adjustable antenna stacks (44A) and (44B) with physical separation providing space diversity. Each antenna stack (44A) or (44B) has two polarizations associated with independently adjustable electrical tilt angles. The electrical tilt angles of each antenna stack (44A) or (44B) are controlled to be equal to those of the other antenna stack to provide co-polarization or anti-polarization tilt coupling. The antenna system (40) may operate with multiple carrier frequencies each associated with a respective pair of polarizations of different antenna stacks (44A) and (44B) with co-polarization or anti-polarization tilt coupling. Antenna tilt angles are controllable so that different carrier frequencies are associated with independently adjustable angles of electrical tilt. The system may be used with groups of both contiguous and non-contiguous carrier frequencies.