Antenna and method of assembly of such antenna

Abstract

An antenna comprising: a longitudinal support member for supporting components of the antenna and a method of assembling such an antenna is disclosed. The components supported by the longitudinal member comprise: at least one signal feed probe configured to capacitively supply a signal to a corresponding at least one radiating patch; the at least one radiating patch mounted to at least partially wraparound the longitudinal support member; and signal supply circuitry for supplying a signal to the at least one signal feed. The signal supply circuitry is mounted on an outer surface of the inner longitudinal support member; and the longitudinal support member is formed of a conductive material and forms a ground plane for the antenna.

Claims

1. An antenna comprising a longitudinal support member for supporting components of said antenna, said components comprising: at least one signal feed probe configured to capacitively supply a signal to a corresponding at least one radiating patch, said at least one radiating patch mounted to at least partially wraparound said longitudinal support member, and signal supply circuitry for supplying a signal to said at least one signal feed probe, wherein said signal supply circuitry is mounted on an outer surface of said longitudinal support member, and wherein said longitudinal support member is formed of a conductive material and forms a ground plane for said antenna, said antenna further comprises at least one retaining member for mounting said at least one of said signal supply circuitry and said signal feed probe onto said longitudinal support member, at least a portion of an outer perimeter of said retaining member comprises at least a portion of a circumference of a circle, said at least one radiating patch being mounted around at least a portion of said retaining member.

2. An antenna according to claim 1, wherein said at least one signal feed probe is mounted on said longitudinal support member at a predetermined distance from said longitudinal support member, and said signal supply circuitry extends to contact said signal feed probe.

3. An antenna according to claim 1, wherein said longitudinal support member comprises at least two longitudinally extending surfaces angled with respect to each other, said at least one signal feed probe being mounted at a predetermined distance from an external one of said surfaces and said signal supply circuitry being mounted on an external other one of said surfaces.

4. An antenna according to claim 3, wherein said longitudinal support member comprises a U-shaped rod, said at least one signal feed probe and said signal supply circuitry being mounted with respect to outer surfaces of said U-shaped rod that are substantially at right angles to each other.

5. An antenna according to claim 1, wherein said retaining member comprises a resilient portion, said resilient portion being configured to bias said signal supply circuitry against said longitudinal support member.

6. An antenna according to claim 1, comprising a plurality of signal feed probes and a corresponding plurality of radiating patches.

7. An antenna according to claim 6, comprising a plurality of retaining members, a number of said retaining members being equal to said number of radiating patches.

8. An antenna according to claim 1, said antenna comprising a dual band antenna, said antenna comprising a first portion configured to operate in a first frequency band and a second portion configured to operate in a second frequency band, said first and second portion being arranged subsequent to each other in a longitudinal direction, said antenna comprising an input port at a longitudinal end adjacent to said first portion for receiving two signal feed probe cables for respectively supplying signals in said first frequency band and signals in said second frequency band, said antenna comprising a signal feed probe supply cable for supplying a signal from said input port to said second portion, said signal feed probe supply cable being configured to run parallel to and be at least partially shielded by said longitudinal support member.

9. A method of assembling an antenna according to claim 1, said method comprising: mounting at least one signal feed probe configured to capacitively supply a signal to a corresponding at least one radiating patch on at least one retaining member, mounting said at least one retaining member on a longitudinal support member, such that said at least one signal feed probe is held at a predetermined distance from said longitudinal support member, mounting signal supply circuitry for supplying a signal to said at least one signal feed probe on an outer surface of said longitudinal support member, wrapping at least one radiating patch at least partially around said longitudinal support member, wherein said longitudinal support member is formed of a conductive material and provides a ground plane for said antenna, wherein at least a portion of an outer perimeter of said retaining member comprises at least a portion of a circumference of a circle, said method comprises mounting said at least one radiating patch on two circumferentially remote points on an outer surface of said at least one retaining member such that said radiating patch wraps around said at least one retaining member.

10. A method according to claim 9, wherein said retaining member comprises a resilient portion and said step of mounting said signal supply circuitry on said longitudinal support member comprises biasing said signal supply circuitry against an outer surface of said longitudinal support member using said resilient portion.

11. A method according to claim 9, comprising connecting said signal supply circuitry to said at least one signal feed probe using solder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

(2) FIG. 1 illustrates the signal feed probes mounted on clips;

(3) FIG. 2 shows the longitudinal support member mounted within the clips on which the signal feed probes are mounted;

(4) FIG. 3 shows signal supply circuitry mounted pressed against the longitudinal member by resilient means on the clips;

(5) FIG. 4 shows how the resilient means are attached to the clips;

(6) FIG. 5 shows a section view of the antenna;

(7) FIG. 6 shows a portion of the assembled antenna;

(8) FIG. 7 shows a dual band omnidirectional antenna according to an embodiment;

(9) FIG. 8 shows a signal input coupled to signal feed circuitry according to an embodiment;

(10) FIG. 9 shows the wrapped antenna patches of an embodiment; and

(11) FIG. 10 shows an outer view of the antenna of an embodiment within a radome.

DESCRIPTION OF THE EMBODIMENTS

(12) Before discussing the embodiments in any more detail, first an overview will be provided.

(13) Embodiments provide a lightweight multi directional antenna. Generally much of the structural integrity of a multi directional antenna is provided by the radome. Owing to the internal longitudinal support member of antennas according to embodiments a thinner, less structurally robust radome can be used leading to a robust antenna with a lighter weight structure.

(14) The radiating patches used for omnidirectional radiating patterns are put in place to surround the skeleton of the antenna. The radiating patches comprise flexible PCBs rolled around the skeleton. This step may be performed towards the end of the antenna assembly process. Embodiments provide a structure with an essentially fishbone architecture. An internal longitudinal support member provides much of the internal structure of the antenna and provides support for the components mounted thereon. This allows the radome to be formed of a lightweight material that is transparent to the signals emitted by the antenna.

(15) Such a structural design can be used for both single band and dual band omnidirectional antenna, the latter having two independent antennas placed one above the other, each one with a dedicated connector or signal feed.

(16) Where the antenna is a dual signal antenna, then the inner longitudinal support member with angled sides is able to both guide and shield the signal input cable to the portion of the antenna remote from the signal input operable to transmit the second signal. The architecture also simplifies the antenna's overall assembly, and reduces the number of parts.

(17) In effect the antenna itself creates the structure of the overall design.

(18) In embodiments the radiating elements are formed of patches that are wrapped around the central structure. The central structure comprises signal feed probe(s) for providing the signal to the radiating patch(es). These are formed on a single PCB which runs along the length of the antenna. Clips are provided periodically along the length of the signal feed probe PCB and a U shaped metallic rod is held in position in U-shaped recesses within the clips (FIGS. 1 and 2). This metallic rod provides much of the structural support for the antenna and also forms a ground plane for many of the elements.

(19) A second PCB used as a signal supply circuitry to supply a signal to the signal feed probe(s) is mounted on an outer surface of the U-shaped rod and is locked in place by resilient closure members which attach to the plastic clips. The overall design with the rod as the backbone provides a fishbone type structure that provides strength to the design with a relative low weight (see FIG. 3).

(20) The closure member portion of the clip is slid inside the lower plastic part of the clip, and exerts pressure between the feeding PCB and the U shaped rod (see FIG. 4). As a result, grounding of the PCB is provided by the metallic rod and the space available inside this U-shaped rod can be used for the input signal cable (see FIG. 5, section view) where required.

(21) The lower plastic part of the clip supports the signal feed probe PCB and the two PCBs extend at right angles to each other. The mounting of the two PCBs in this way allows electrical connection of the signal supply PCB and signal feed probe PCB using soldering without the need to hold these PCBs in place (see FIG. 10).

(22) In one embodiment two omnidirectional antennas having different frequency bands are superimposed one on top of the other. The overall antenna has two connectors at the bottom to feed the two antennas operating in different frequency bands (see FIG. 7).

(23) The overall design provides a particularly effective antenna for such an arrangement, the feeding cable of antenna 2 being guided and shielded inside antenna 1 using the U shaped metallic profile.

(24) In embodiments a flexible PCB provides the radiating patches. The patches are printed on a flexible PCB, which is then rolled around the fishbone structure. The patches are attached on one side with a dedicated cut-out on the PCB and a matching shape on the supporting plastic clip, they are then rolled around the antenna, and locked in place with a plastic rivet (see FIGS. 8 to 10).

(25) Assembly of the antenna follows the following steps. Plastic clips 10 with a curved outer surface and a U-shaped central recess are mounted along a PCB 12 comprising signal feed probes 32 in the form of tracks on the PCB (FIG. 1). A U-shaped metallic rod 10 is slid into the U-shaped central recess of the clip (FIG. 2) and a PCB with signal supply circuitry is mounted on the U-shaped rod at right angles to the signal feed probe PCB 30 (FIG. 3). The signal supply circuitry PCB 30 is held biased against the metallic U-shaped rod by resilient portions 14 that slide into the plastic clips 10 (FIG. 4). A clip with a substantially circular outer circumference is in this way provided for holding the different components of the antenna at different places along the length of the antenna (FIGS. 5 and 6).

(26) An electrical connection between the signal supply circuitry on one PCB and the signal feed probes on the other can then be made in a straightforward manner by soldering (FIG. 10).

(27) A flexible material comprising flexible radiating patches 40 is then wrapped around the inner components of the antenna and held in place by rivets which pass through holes in the flexible material and slot into recesses in the circular clips. The circular outer circumference of the clips provides support and gives a circular form to the flexible material of the radiating elements 40 and holds them at a fixed distance from the signal feed probes with which they are capacitively coupled (see FIGS. 9 and 10).

(28) A signal feed input 5o is provided towards one end of the antenna. It is configured to receive one or more signal input cables and is electrically coupled to the signal supply circuitry (see FIG. 8). Where there are two antennas in a line (FIG. 7), then the signal input for the second antenna is coupled to a cable running within the U-shaped metallic rod, which is then electrically coupled to the signal supply circuitry of antenna 2.

(29) In summary embodiments provide a low weight, robust quasi-omnidirectional antenna, which in some embodiments provides 2 antennas operational at the same time. Furthermore, the antenna is cost efficient being made of a limited number of simple parts.

(30) It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the invention. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo code, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

(31) The description and drawings merely illustrate the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be only for pedagogical purposes to aid the reader in understanding the principles of the invention and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.