Abstract: A phased array antenna system with electrical tilt control incorporates a tilt controller (62) for splitting an input signal into three intermediate signals, two of which are delayed by variable delays T1 and T2 relative to the third. A corporate feed (64) contains splitters S3 to S10 and hybrids H1 to H6 for processing the intermediate signals to produce drive signals for elements of an antenna array (66); the drive signals are fractions and vector combinations of the intermediate signals. The tilt controller (62) and the corporate feed (64) in combination impose relative phasing on the drive signals as appropriate for phased array beam steering in response to variable delay of two intermediate signals relative to the third intermediate signal.

Abstract: A phased array antenna system with electrical tilt control incorporates a tilt controller (62) for splitting an input signal into three intermediate signals, two of which are delayed by variable delays T1 and T2 relative to the third. A corporate feed (64) contains splitters S3 to S10 and hybrids H1 to H6 for processing the intermediate signals to produce drive signals for elements of an antenna array (66); the drive signals are fractions and vector combinations of the intermediate signals. The tilt controller (62) and the corporate feed (64) in combination impose relative phasing on the drive signals as appropriate for phased array beam steering in response to variable delay of two intermediate signals relative to the third intermediate signal.

Abstract: A phased array antenna system with electrical tilt control incorporates a tilt controller (62) for splitting an input signal into three intermediate signals, two of which are delayed by variable delays T1 and T2 relative to the third. A corporate feed (64) contains splitters S3 to S10 and hybrids H1 to H6 for processing the intermediate signals to produce drive signals for elements of an antenna array (66); the drive signals are fractions and vector combinations of the intermediate signals. The tilt controller (62) and the corporate feed (64) in combination impose relative phasing on the drive signals as appropriate for phased array beam steering in response to variable delay of two intermediate signals relative to the third intermediate signal.

Abstract: A phased array antenna system with multiple beams incorporates a CDMA base station (32) with multiple ports 341to 36N for positive and negative polarisation signals connected to ports 401 to 42N of an antenna assembly (44). The antenna assembly (44) is single stack and multi-port, and it provides multiple antenna beams with polarisation diversity and different vertical angles of electrical tilt which are fixed or variable. It is suitable for 3G mobile radio using CDMA. Different antenna beams may carry groups of data channels distinguished either by different channelisation process coding or by different scrambling process coding. An operator may use two or more beams simultaneously. Control of angle of electrical tilt of antenna beams may be implemented by introducing variable relative delay between signals associated with different antenna ports A(+) and B(+) and feeding them to a signal splitting and combining network providing antenna element signals.

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: 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.

Abstract: A phased array antenna system with variable electrical tilt comprises an array of antenna elements etc. incorporating a divider dividing a radio frequency (RF) carrier signal into two signals between which a phase shifter introduces a variable phase shift. A phase to power converter converts the phase shifted signals into signals with powers dependent on the phase shift. Power splitters 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 etc. combine pairs of divided signals from different power splitters this provides vector sum and difference components with appropriate phase for supply to respective pairs of antenna elements etc. located equidistant from an array center. Adjustment of the phase shift provided by phase shifter changes the angle of electrical tilt of the antenna array.

Abstract: Methods for coded aperture imaging, and processing the data from coded aperture imaging are taught. Several snapshots of an image are acquired, each using a different coded aperture array. The several snapshots are combined together with appropriate weightings to form a single equivalent frame as are the aperture functions for the coded aperture arrays used. Combining several frames of data can improve the signal to noise ratio of the decode image and increase the resolution of the image. Preferably a balanced weighting system is used and image reconstruction is performed by inverting the covariance matrix formed by the covariance of the signals from a number of estimated trial points. Using a balanced weighting system reduces the covariance matrix to a diagonal or near diagonal matrix with a corresponding reduction in computational load. The techniques also reduces additive noise.

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

Abstract: A phased array antenna system with two dimensional scanning includes a two dimensional array A of antenna elements A1,1 to A12,12 arranged in lines; each line is associated with a respective first rank corporate feed network 161 to 1612 having outputs 171,1 to 1712,12 connected to respective antenna elements A1,1 to A12,12 and inputs for variable relative phase input signals. These corporate feed networks each have first and second inputs A1/B1 to A12/B12 connected respectively to outputs 171 CD/1712CD to 171EF/1712EF of different second rank corporate feed networks 16CD and 16EF. The corporate feed networks 161 to 16EF convert input signals of variable relative phase into relatively greater numbers of output signals for a phased array.

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

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: 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.

Abstract: An electrically steerable phased array antenna system includes an array of antenna elements and a corporate feed network having an inner region for input of two input signals A and B. The corporate feed network has two outer regions and generating vector combinations of respective input signals and other input signal fractions. Each outer region has a splitting and combining network providing the vector combinations as signals to antenna elements connected predominantly peripherally to itself. Each splitting and combining network has input signal connections from the inner region disposed peripherally of the corporate feed network. Each consists of splitters and adding/subtracting elements implemented as hybrid couplers some of which have re-entrant or meandered track sections. Hybrid meandered track sections have multiple widths for signal weighting. The corporate feed network is configured to avoid track cross-overs.

Abstract: A phased array antenna system with two dimensional scanning includes a two dimensional array A of antenna elements A1,1 to A12,12 arranged in lines; each line is associated with a respective first rank corporate feed network 161 to 1612 having outputs 171,1 to 1712,12 connected to respective antenna elements A1,1 to A12,12 and inputs for variable relative phase input signals. These corporate feed networks each have first and second inputs A1/B1 to A12/B12 connected respectively to outputs 171 CD/1712CD to 171EF/1712EF of different second rank corporate feed networks 16CD and 16EF. The corporate feed networks 161 to 16EF convert input signals of variable relative phase into relatively greater numbers of output signals for a phased array.

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.

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.

Abstract: A phased array antenna system with multiple beams incorporates a CDMA base station (32) with multiple ports 341 to 36N for positive and negative polarisation signals connected to ports 401 to 42N of an antenna assembly (44). The antenna assembly (44) is single stack and multi-port, and it provides multiple antenna beams with polarisation diversity and different vertical angles of electrical tilt which are fixed or variable. It is suitable for 3G mobile radio using CDMA. Different antenna beams may carry groups of data channels distinguished either by different channelisation process coding or by different scrambling process coding. An operator may use two or more beams simultaneously. Control of angle of electrical tilt of antenna beams may be implemented by introducing variable relative delay between signals associated with different antenna ports A(+) and B(+) and feeding them to a signal splitting and combining network providing antenna element signals.

Abstract: Methods for coded aperture imaging, and processing the data from coded aperture imaging are taught. Several snapshots of an image are acquired, each using a different coded aperture array. The several snapshots are combined together with appropriate weightings to form a single equivalent frame as are the aperture functions for the coded aperture arrays used. Combining several frames of data can improve the signal to noise ratio of the decode image and increase the resolution of the image. Preferably a balanced weighting system is used and image reconstruction is performed by inverting the covariance matrix formed by the covariance of the signals from a number of estimated trial points. Using a balanced weighting system reduces the covariance matrix to a diagonal or near diagonal matrix with a corresponding reduction in computational load. The techniques also reduces additive noise.