Antenna Assembly and Antenna System

Abstract

Antenna assembly comprising the combination of a steerable phased array antenna with omnidirectional sector and a GNSS antenna, and antenna system comprising the antenna assembly.

Claims

1-14. (canceled)

15. An antenna assembly (100) comprising: a steerable phased array antenna (200) with omnidirectional sector and a GNSS antenna (300), the steerable phased array antenna (200) with omnidirectional sector being formed by a truncated cone-shaped bottom reflector (210) with a wide end and a smaller pointing end and a truncated cone-shaped top reflector (220) with a wide end and a smaller pointing end arranged in a superposition facing each other with their respective pointing ends, the steerable phased array antenna (200) with omnidirectional sector being arranged in a spacing (250) between the said truncated cone-shaped bottom reflector (210) and truncated cone-shaped top reflector (220), wherein the truncated cone-shaped bottom reflector (210) and truncated cone-shaped top reflector (220) are reflective for signals of the omnidirectional steerable phased array antenna (200), and the truncated cone-shaped top reflector (220) is further transparent for GNSS signals for the GNSS antenna (300).

16. The antenna assembly (100) according to claim 15, wherein the truncated cone-shaped bottom reflector (210) is provided with a centrally arranged hole (211) at its pointing end adapted for receiving and accommodating the GNSS antenna (300).

17. The antenna assembly (100) according to claim 16, wherein the steerable phased array antenna (200) with omnidirectional sector is formed by an array antenna (230) with at least three antenna elements (231) or by at least four antenna (231).

18. The antenna assembly (100) according to claim 15, wherein the steerable phased array antenna (200) with omnidirectional sector is formed by an array antenna (230) with at least three antenna elements (231) or by at least four antenna (231).

19. The antenna assembly (100) according to claim 17, wherein the antenna elements (231) are monopole antennas or dipole antennas.

20. The antenna assembly (100) according to claim 17, wherein the antenna elements (231) are arranged to protrude upwards from the truncated cone-shaped bottom reflector (210) in a direction toward the truncated cone-shaped top reflector (220) within the spacing (250) therebetween but not in contact with the truncated cone-shaped top reflector (220).

21. The antenna assembly (100) according to claim 20, wherein the truncated cone-shaped bottom reflector (210) is provided with through holes (212) at frustum thereof, adapted for receiving and accommodating the antenna elements (231).

22. The antenna assembly (100) according to claim 15, further comprising a housing (400) formed by a main body (410) and a top cover (420) with an open end and a closed opposite end, wherein the top cover (420) is detachably arranged to the main body (410) at the open end.

23. The antenna assembly (100) according to claim 22, wherein the truncated cone-shaped bottom reflector (210) is fixed to the main body (410) and the truncated cone-shaped top reflector (220) is fixed to the top cover (420) interior at the closed end thereof, and there is no physical or electrical connection between the truncated cone-shaped bottom reflector (210) and the truncated cone-shaped top reflector (220).

24. The antenna assembly (100) according to claim 23, wherein the antenna elements (231) and the GNSS antenna (300) are arranged on a common platform.

25. The antenna assembly (100) according to claim 15, wherein the antenna elements (231) and the GNSS antenna (300) are arranged on a common platform.

26. The antenna assembly (100) according to claim 20, wherein the antenna elements (231) and the GNSS antenna (300) are arranged on a common platform.

27. The antenna assembly (100) according to claim 15, wherein the shape of the truncated cone-shaped bottom reflector (210) and truncated cone-shaped top reflector (220) forms gain of the steerable phased array antenna (200) with omnidirectional sector and maximizes radiation pattern of the steerable phased array antenna (200) with omnidirectional sector in a 360 degree sector in horizontal plane of the steerable phased array antenna (200).

28. The antenna assembly (100) according to claim 15, wherein lobe elevation beam width of the steerable phased array antenna (200) with omnidirectional sector is given by length of sloping plane of the truncated cone-shaped bottom reflector (210) and truncated cone-shaped top reflector (220) and operating frequency.

29. The antenna assembly (100) according to claim 20, further comprising a housing (400) formed by a main body (410) and a top cover (420) with an open end and a closed opposite end, wherein the top cover (420) is detachably arranged to the main body (410) at the open end.

30. The antenna assembly (100) according to claim 29, wherein the truncated cone-shaped bottom reflector (210) is fixed to the main body (410) and the truncated cone-shaped top reflector (220) is fixed to the top cover (420) interior at the closed end thereof, and there is no physical or electrical connection between the truncated cone-shaped bottom reflector (210) and the truncated cone-shaped top reflector (220).

31. An antenna system comprising the antenna assembly (100) according to claim 15, comprising an antenna processing module (500) provided with software for controlling phase and amplitude of the individual antenna elements (231), and oscillators (501) controlling operational frequency of the steerable phased array antenna (200) with omnidirectional sector.

32. The antenna system according to claim 31, further comprising a time reference module (800) arranged to extract a time reference from a GNSS receiver module (700) arranged to the GNSS antenna (300).

33. The antenna system according to claim 32, wherein the antenna processing module (500) is arranged to use the time reference from the time reference module (800) for calibration of the oscillators (501) controlling the operational frequency, and time synchronization of a radio module (600).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention will below be described in further detail with reference to the attached drawings, where:

[0047] FIG. 1 is a principle drawing of an embodiment of an antenna assembly and antenna system according to the disclosure,

[0048] FIG. 2 is a block diagram of the antenna system according to the disclosure, and

[0049] FIG. 3 is a principle drawing of an alternative embodiment of a housing for the antenna assembly and antenna system.

DETAILED DESCRIPTION

[0050] Reference is now made to FIG. 1 which is a principle drawing of an antenna assembly 100 according to the disclosure. The antenna assembly 100 comprises a steerable phased array antenna 200 with omnidirectional sector and a GNSS antenna 300, arranged in a housing 400.

[0051] The steerable phased array antenna 200 with omnidirectional sector is formed by a truncated cone-shaped bottom reflector 210 and a truncated cone-shaped top reflector 220 and an antenna array 230.

[0052] The truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 are arranged in a superposition facing each other with pointing end thereof. The truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 are arranged spaced apart in vertical direction with a common vertical center axis 240, providing a spacing 250 therebetween. The antenna array 230 is arranged in the mentioned spacing 250.

[0053] The truncated cone-shaped bottom 210 and top reflector 220 are reflective for signals of the steerable phased array antenna 200 with omnidirectional sector, and the truncated cone-shaped top reflector 220 is further transparent for GNSS signals for the GNSS antenna 300. The truncated cone-shaped bottom 210 and top 220 reflector are reflective for signals of e.g. broadband radio signals in the order of 5 GFIz, while the truncated cone-shaped top reflector 220 will be transparent for GNSS signals, which typically will be in the order of 1-2 GFIz, which signals will not interfere with each other.

[0054] The antenna array 230 is formed by at least three antenna elements 231, and even more preferably at least four antenna elements 231. The antenna elements 231 may be monopole antennas, as shown in the example embodiments, or dipole antennas. The antenna elements 231 will be distributed along the circumference of the frustum of the truncated cone-shaped bottom reflector 210 with an extension in the vertical plane towards the truncated cone-shaped top reflector 220, but not in contact with the truncated cone-shaped top reflector 220.

[0055] The truncated cone-shaped bottom reflector 210 is further provided with a centrally through hole 211 adapted for receiving and accommodating the GNSS antenna 300.

[0056] The truncated coned-shaped bottom reflector 210 is further provided with through holes 212 at the frustum thereof, i.e. the pointing end, adapted for receiving and accommodating the antenna elements 231.

[0057] The through holes 212 for the antenna elements 231 preferably exhibit a larger diameter than the antenna elements 231 such that there is no physical or electrical contact between the antenna elements 231 and the truncated cone-shaped bottom reflector 210.

[0058] The housing 400 is formed by a main body 410 and top cover 420. The main body 410 is adapted for arrangement/fixation of the antenna assembly 100 to an object, such as an offshore or onshore craft, as well as accommodating components for powering and controlling the antenna assembly 100, as will be further described below. The cover 410 is adapted for accommodation of the steerable phased array antenna 200.

[0059] The top cover 420 is exhibiting a mainly cylinder shape and is closed at upper end and open at the lower end, wherein the lower end of the top cover 420 and the upper part of the main body 410 are provided with corresponding attachment means, such as threads, for detachable attachment of the top cover 420 to the main body 410. The top cover 420 is formed by a material transparent for both GNSS signals and phased array antenna signals. There is preferably arranged sealing means (not shown), such as an O-ring, between the main body 410 and the top cover 420 ensuring a sealed environment for the components of the antenna assembly 100/antenna system.

[0060] The truncated cone-shaped bottom reflector 210 is fixed to the upper end of the main body 410 by corresponding attachment means (not shown), while the truncated cone-shaped top reflector 220 is fixed to the closed end of the top cover 420 by attachment means (not shown), at interior side thereof.

[0061] Accordingly, when the top cover 420 is arranged to the main body 410, the truncated cone-shaped top reflector 220 will be positioned above the truncated cone-shaped bottom reflector 210 with a desired distance therebetween, which distance is at least longer than the extension of the antenna elements 231 to ensure that the truncated cone-shaped top reflector 220 is not in physical or electrical contact with the antenna elements 231. The distance may e.g. be twice the length of the monopole antennas 231 such that both the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 are positioned with the same distance from the upper (transmitting) end of the antenna elements 231. Depending on the desired properties of the steerable phased array antenna 200, the distance of the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 from the upper end of the monopole antennas 231 may be different.

[0062] Accordingly, the truncated cone-shaped top reflector 220 will be “floating” above the truncated cone-shaped bottom reflector 210 and there is no physical or electrical connection between the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220.

[0063] The shape of the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 may be similar or different, and together form gain of the steerable phased array antenna 200 with omnidirectional sector and maximizes radiation pattern of the steerable phased array antenna 200 with omnidirectional sector in a 360 degree sector in horizontal plane of the steerable phased array antenna 200.

[0064] Further, the lobe elevation beam width of the steerable phased array antenna 200 with omnidirectional is given by length and inclination (angle in relation to the vertical plane) of sloping plane of the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220, and operating frequency, which will further described below.

[0065] In general, it will be such that the inclination of the sloping plane of the truncated cone-shaped bottom reflector 210 and truncated cone-shaped top reflector 220 will provide a narrower beam the smaller the angle is in relation to the vertical plane, and a wider beam the larger the angle is in relation to the vertical plane,

[0066] Reference is now made to FIG. 2 showing a block diagram of an antenna system. The antenna system in addition to the above described antenna assembly 100 comprises an antenna processing module 500 provided with means and/or software for controlling the antenna array 230 of the steerable phased array antenna 200, The antenna processing module 500 is arranged for controlling of the antenna array 230, i.e. the individual antenna elements 231, by controlling phase and amplitude of the individual antenna elements 231. The antenna processing module 500 further comprises oscillators 501 controlling the operational frequency of the steerable phased array antenna 200 with omnidirectional sector.

[0067] The antenna system further comprises a radio module 600 for controlling the radio communication to and from the antenna system in communication with an external unit 650 for input or output of communication data/information. Input data will typically be knowledge about direction of the receiver and which signal level the receiver needs to be able to decode the signal, which information will be a part of the communication protocol between two antenna systems to communicate as mentioned above.

[0068] The antenna system further comprises a GNSS receiver module 700 connected to the GNSS antenna 300, typically in the form of a printed circuit board.

[0069] The antenna system will typically further comprise a time reference module 800 for extracting a time reference from the received GNSS signal that will be supplied to the antenna processing module 500 and the radio communication module 600, The antenna processing module 500 uses the time reference for calibration of the oscillators 501 controlling the operational frequency, and time synchronization. The antenna system may make use of TDMA, either as a single frequency channel half-duplex system, or as a full-duplex system with separate channels for TX and RX.

[0070] The radio module 600 will make use of the time reference for maintaining track of transmission time slots.

[0071] The antenna processing module 500 can be implemented as a printed circuit board.

[0072] According to one disclosed embodiment the mentioned antenna elements 231 of the antenna array 230 and GNSS antenna 300 are arranged to a common platform/printed circuit board, i.e. the lower end of the antenna elements 231 are arranged to the common platform/printed circuit board.

[0073] Accordingly, the common platform/printed circuit board with the GNSS antenna 300 and antenna elements 231, during assembly, is moved from lower side of the truncated cone-shaped bottom reflector 210 such that the antenna elements 231 are received and positioned via the through holes 212 as well as positioning the GNSS antenna 300 in the centrally through hole 211, wherein the common platform/printed circuit board is fixed in accurate position in relation to the truncated cone-shaped bottom reflector 210 by corresponding fastening means (not shown), such as screws and threaded holes. By this is achieved as short as possible transmission line between the antenna elements 231 and the truncated cone-shaped bottom 210 and top 220 reflector, due to the free end (transmitting end) of the antenna elements 231 are positioned in the spacing 250 between the truncated cone-shaped bottom reflector 210 and the truncated cone-shaped top reflector 220.

[0074] There will preferably be arranged insulating means, such as one or more gaskets (not shown), between the truncated cone-shaped bottom reflector 210 and common platform/printed circuit board for sealing therebetween as well as ensuring that the there is no electrical contact with the truncated cone-shaped bottom reflector 210.

[0075] In the described embodiment the GNSS antenna 300 and steerable phased array antenna 200 with omnidirectional sector will thus have the same ground-plane. This is not a requirement, but will be practical for reducing the size of the components and providing a compact unit. The steerable phased array antenna 200 with omnidirectional sector may alternatively be provided with a separate printed circuit board if desired.

[0076] The antenna system is powered by a power supply 900 and the antenna processing module 500 may be arranged for controlling the power to the steerable phased array antenna 200 and optionally the GNSS antenna 300.

[0077] Reference is now made to FIG. 3 showing an alternative embodiment of the main body 410. The main body 410 and the components of the antenna system arranged therein, i.e. all components below the truncated cone-shaped bottom reflector 210 is in metal, which will affect the antenna performance, and hence may need to be compensated for. When the main body 410 and the components are of metal or containing metal, these will act as an extension of the truncated cone-shaped bottom reflector 210 and will thus have to be considered when designing the antenna system. By providing the main body 410 with corrugated sides (not shown), this will balance the mass of the main body 410, and contributing to an improved horizontal radiation pattern (with fixed elevation).

[0078] In the shown embodiment the main body 410 is further provided with slotted/recessed longitudinal sides 430 reducing the size and weight thereof.

[0079] An advantage with the disclosed embodiments is that there is a short transmission line to the antenna elements 231 that results in low losses.

[0080] A controllable antenna system where one may adapt transmission direction and power to a known receiver is provided.

[0081] When using steerable phased array antenna providing parabolic radiation pattern this requires attitude compensation when the antenna system is arranged on a movable object. With the steerable phased array antenna system according to the disclosure, it is possible to have high gain towards the receiver for maintaining positive link margin over range, and steer the antenna direction to compensate for the object, such as a vessel or craft, dynamically behavior. The controlling is performed independently of motion of the object, as only the radio signals are used, resulting in continuous and rapid controlling.

[0082] The antenna system disclosed herein may further be arranged for using the position data provided by the GNSS antenna 300. Frequencies and power levels may be dependent on the geographical position (different jurisdiction). Manual procedures to change the frequency and power levels is time consuming and cumbersome and may lead to human errors when changing the required parameters. In order to solve this problem, information about geographical areas and limitations regarding spectrum and power levels may be stored in a database which can be used for selecting the appropriate parameters for the actual geographical area by the use of position data. In this way, the antenna system is arranged to use position data as input in order to set the dependent parameters according to the current geographical position.

Modifications

[0083] Several antenna assemblies can be arranged above each other or possibly several antenna system can be arranged above each enabling control also in elevation.

[0084] The antenna assembly may be provided with controllable inclined sides of the truncated cone-shaped bottom and/or top reflector, which can be controlled individually or together. By controlling the inclination of the sides of the truncated cone-shaped bottom and/or top reflector the narrowness of the beam can be controlled and/or elevation.