Abstract: The invention provides for a broad band directional antenna (10) comprising a ground plane (12) having an axis (14) extending perpendicularly to the ground plane, an active radiator (13) which is axially spaced from the ground plane, a metamaterial ground plane assembly (16) and a conductive pillar (28.1) between the first conductive wall and the ground plane. The metamaterial ground plane assembly comprises a metamaterial ground plane (17), a first conductive wall (20) adjacent a periphery of the metamaterial ground plane, the first conductive wall having a bottom (22) and atop (24) and a second wall (26) comprising two mutually insulated conductive wall parts (26.1, 26.2) located spaced from and outside of the first conductive wall. The bottom of the first conductive wall is located between the ground plane and the metamaterial ground plane and the top of the first conductive wall is located beyond the active radiator.

Abstract: An antenna 10 comprises a single wire wound in a helix 12 comprising a plurality of turns 1, 2, 3, n, n+1, . . . p around a main axis 11 with immediately adjacent turns having an inter-turn spacing between them. The helix has a back end 14 and a front end 16 and the main axis defines a main beam direction. A transverse crosssectional area of the helix monotonously decreases from the back end 14 to the front end 16. The inter-turn spacing S1 . . . Sn . . . monotonously decreases from the backend 14 to the front end 16. A feed-point 13 is provided at the back end 14.

Abstract: A communications system 10 comprises a source arrangement 12 of periodic waves. The source arrangement is configured to generate an interferometric wave pattern having a plurality of lobes 18.1 to 18.13. Each lobe has a main axis 20 diverging from an origin 22 at the source arrangement and a null 24 between any two adjacent lobes. At least one sensor arrangement 26 is provided for the waves. The sensor arrangement comprises a first sensor 28 and a second sensor 30 which are spaced from one another. A first signal source 40 is connected to the source arrangement 12 via a phase shift arrangement 41 to generate a first interferometric wave pattern 18 which illuminates the first sensor 28 more than the second sensor 30. A second signal source 42 is connected to the source arrangement via the phase shift arrangement to generate a second interferometric pattern 46 which is off-set from the first interferometric pattern and which illuminates the second sensor more than the first sensor.

Abstract: A system 10 for providing communication services to user stations 14.1 to 14.n which are spaced on first and second opposed sides 16, 18 of an elongate corridor 12, comprises a first node 20 and a second node 22. The nodes drive respective radiation patterns comprising at least first, second, third and fourth lobes 30, 32, 34 and 36 having respective main axes 38, 40, 42 and 44. The arrangement is such that in respect of the second corridor node: main axis 38 is directed towards a first region 14.27 which is on the first side 16, to illuminate stations on the first side; main axis 40 is directed towards a second region 14.46 which is on the second side 18, to illuminate stations on the second side; main axis 42 is directed towards a third region 14.10 which is on the first side, to illuminate stations on the first side; and main axis 44 is directed towards a fourth region 14.63, to illuminate stations on the second side.

Abstract: A monitoring system 22 for a distributed antenna system (DAS) 10 is provided. The DAS comprises central transmitter 12 which is connected by a signal transmission network 14 to a plurality of distributed antenna devices (DAD) 16.1 to 16.n. The network comprises physical branches. Each of the DAD's is connected to a respective sub-branch 14.11 and comprises at least one antenna 18. The antenna is associated with a frequency band having a center frequency fc and an associated wavelength Ac. The monitoring system comprises a central monitoring unit (CMU) 24 which is coupled to the network 14. A monitoring device 28.1 is associated with at least one of the DAD's and permanently mounted a distance d<2?c away from the antenna of the DAD. The monitoring device comprises a controller 30, a transceiver 32 and an antenna 34.

Abstract: An antenna 10 comprises at least a first pair 12 of elongate radiating elements and a second pair 14 of elongate radiating elements. Each pair comprises a first element 12.1 and a second element 12.2. Each element has a feed end 12.11 and a distal end 12.12. The first and second elements of each of the at least first pair and second pair have their respective feed ends 12.11, 12.21 in juxtaposition relative to one another and extend in diverging relationship relative to one another in a direction from their feed ends towards their distal ends. The at least first and second pairs are electrically connected in parallel. In some embodiments the elements may diverge exponentially. The invention also relates to antennas which may be packaged in at least partially knock-down form to be assembled or deployed conveniently at a user site.

Abstract: A collapsible antenna (10) comprises an elongate boom (12) having a main axis (14) and a plurality of elongate radiating elements (16) having respective first ends (18.1) and respective second ends (18.2). At least some of the elongate radiating elements are flexible and are mounted at the respective first ends to the boom in longitudinally spaced relation. Regions towards the respective second ends of the at least some of the elongate radiating elements engage a flexible rope (20). The flexible rope forms part of a frame (22) which is manipulatable relative to the boom between a first collapsed configuration and a second operative configuration wherein the at least some radiating elements are in an operative configuration relative to the boom.

Abstract: A collapsible antenna (10) comprises an elongate boom (12) having a main axis (14) and a plurality of elongate radiating elements (16) having respective first ends (18.1) and respective second ends (18.2). At least some of the elongate radiating elements are flexible and are mounted at the respective first ends to the boom in longitudinally spaced relation. Regions towards the respective second ends of the at least some of the elongate radiating elements engage a flexible rope (20). The flexible rope forms part of a frame (22) which is manipulatable relative to the boom between a first collapsed configuration and a second operative configuration wherein the at least some radiating elements are in an operative configuration relative to the boom.