Abstract: A phased array antenna system with controllable electrical tilt generates two signals V2a and V2b with variable relative delay therebetween. The signals are converted into antenna element drive signals by a power distribution network. The network splits each of the two signals V2a and V2b into three signal components. Pairs of components of different signals are input respective hybrid coupling devices (hybrids), which provide vector sums and differences of their inputs and act as phase-to-power converters. Their outputs are distributed between further hybrids, which act as power-to-phase converters and provide antenna element drive signals with phase varying both with element array position and also with the variable relative delay between the two signals V2a and V2b. Antenna electrical tilt is therefore controllable by altering a single relative delay.

Abstract: A phased array antenna system with adjustable electrical tilt includes an array (62) of antenna elements 621, to 6210. It has a splitter (44) dividing a radio frequency (RF) carrier signal into two signals between which a phase shifter (46) introduces a variable phase shift. Further splitters (52) and (54) divide the relatively phase shifted signals into two sets of five signals. Four of each of the sets of five signals are vectorially combined in a network of 180 degree hybrid couplers 601, to 604. This provides vector sum and difference components which together with the fifth members of the sets are fed to respective fixed phase shifters (56, 58) and 641, to 6410. The phase shifters 641, to 6410 provide signals which are appropriately phased for use as phased array drive signals for respective antenna elements 621, to 6210. Adjustment of the single phase shift provided by the variable phase shifter (46) changes the angle of electrical tilt of the entire antenna array (62).

Abstract: A phased array antenna system with variable electrical tilt comprises an array (60) of antenna elements (60L1) etc. incorporating a divider (44) dividing a radio frequency (RF) carrier signal into two signals between which a phase shifter (46) introduces a variable phase shift. A phase to power converter (50) converts the phase shifted signals into signals with powers dependent on the phase shift. Power splitters (52, 54) divide the converted signals into two sets of divided signals with total number equal to the number of antenna elements in the array. Power to phase converters (561) etc. combine pairs of divided signals from different power splitters (52, 54) this provides vector sum and difference components with appropriate phase for supply to respective pairs of antenna elements (60U1, 60L1) etc. located equidistant from an array centre. Adjustment of the phase shift provided by phase shifter (46) changes the angle of electrical tilt of the antenna array (60).

Abstract: A mobile-radio base station for a telecommunications system includes vector modulator means for independently controlling the phase and/or amplitude of a plurality of component signals representative of the signal to be transmitted or received, such that when these signals pass through a plurality of antenna elements, a beam is formed in a direction according to the phase relationship of the component signals. The invention also includes interface means allowing other base stations to be coupled to the same antenna, with each base station having independent control of its beam direction. Provision is includes for phase compensation of the signals to correct for errors introduced by unequal and variable component signal path lengths between the base station and the antenna. The vector modulator means is arranged to operate at low power levels, where it can operate more efficiently.