Antenna system for sharing of operation

摘要

An antenna system for sharing of operation employs contiguous transmit frequencies. Transmit frequencies are separated into non-contiguous sub-groups isolated from one another by filters 158(+) and 160(-) associated with positive and negative polarization. Received frequencies are filtered and split into five signals for input to base station receive ports. Non-contiguous transmit frequency sub-groups are combined by a quadrature hybrid 110 and pass with 90 degree relative phase shift to mutually orthogonal antenna stack ports P(+) and P(-) associated with orthogonally polarized sets of antenna elements AS(+) and AS(-): the ports P(+) and P(-) are isolated from one another by the hybrid 110. The 90 degree phase shift results in one transmit subgroup being radiated with left hand circular polarization and the other transmit subgroup being radiated with right hand circular polarization. Changing the relative phase shift changes the radiated polarization to linear or elliptical, and signal amplitude weighting provides control of antenna beam polarization direction.