Abstract: Cross-polar discrimination (XPD) of a dual orthogonal cross-polarized antenna is maximized via a cross-coupling network between base station MIMO branches prior to connection to the base station antenna. In one embodiment, a cross coupling network combines each MIMO branch signal with an attenuated phase reversed (phase shifted) copy of the other MIMO branch signal. The amount of attenuation for each branch is equivalent to the cross polar suppression required for each antenna array. The cross-coupling can be applied at different stages of signal processing within a base station.

Abstract: Cross-polar discrimination (XPD) of a dual orthogonal cross-polarised antenna is maximized via a cross-coupling network between base station MIMO branches prior to connection to the base station antenna. In one embodiment, a cross coupling network combines each MIMO branch signal with an attenuated phase reversed (phase shifted) copy of the other MIMO branch signal. The amount of attenuation for each branch is equivalent to the cross polar suppression required for each antenna array. The cross-coupling can be applied at different stages of signal processing within a base station.

Abstract: 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.

Abstract: An electrically tilted antenna system with polarization diversity has a dual polarized, tilt adjustable antenna (32). The antenna (32) has dipoles (34, 36) of two orthogonal polarizations associated with independently adjustable electrical tilt angles. The tilt angles are implemented by relative delays between corporate feed input or output signals, the delays being introduced by an antenna tilt assembly (54). Two signal feeders (F21, F22) associated with different antenna polarizations connect the antenna tilt assembly (54) to a base station filter assembly (50): the base station filter assembly 50 routes transmit signals from base stations (BS21, BS22) to different antenna polarizations via respective feeders (F21, F22) and the antenna tilt assembly (54). This assembly also divides receive signals from feeders (F21, F22) between both base stations (BS21, BS22).

Abstract: An electrically tilted antenna system with polarisation diversity has a dual polarised, tilt adjustable antenna (32). The antenna (32) has dipoles (34, 36) of two orthogonal polarisations associated with independently adjustable electrical tilt angles. The tilt angles are implemented by relative delays between corporate feed input or output signals, the delays being introduced by an antenna tilt assembly (54). Two signal feeders (F21, F22) associated with different antenna polarisations connect the antenna tilt assembly (54) to a base station filter assembly (50): the base station filter assembly 50 routes transmit signals from base stations (BS21, BS22) to different antenna polarisations via respective feeders (F21, F22) and the antenna tilt assembly (54). This assembly also divides receive signals from feeders (F21, F22) between both base stations (BS21, BS22).

Abstract: A diversity antenna system with electrical tilt has two dual polarised, tilt adjustable antenna stacks (44A) and (44B) with physical separation providing space diversity. Each antenna stack (44A) or (44B) has two polarisations 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-polarisation or anti-polarisation tilt coupling. The antenna system (40) may operate with multiple carrier frequencies each associated with a respective pair of polarisations of different antenna stacks (44A) and (44B) with co-polarisation or anti-polarisation 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.