WO2023084336A1

WO2023084336A1 - Antenna system

Info

Publication number: WO2023084336A1
Application number: PCT/IB2022/059691
Authority: WO
Inventors: Andries Petrus Cronje Fourie; Stephen Joseph FRONEMAN
Original assignee: Poynting Antennas (Pty) Limited
Priority date: 2021-11-12
Filing date: 2022-10-10
Publication date: 2023-05-19

Abstract

The antenna system 10 comprises an antenna carrier 16 having a vertically extending axis 18. A first directional and cross-polarized antenna arrangement 20 having first and second ports is mounted on the carrier such that main axis 24 of the first directional antenna arrangement 20 extends in a first direction A which is orthogonal to the carrier axis 18. A second directional and cross-polarized antenna arrangement 26 having a first and second ports is mounted on the carrier such that a main axis 30 of the second directional antenna arrangement 26 extends in a second direction B which is orthogonal to the carrier axis 18 and angularly offset from the first direction A. The antenna system 10 comprises a multi-input and multi-output (MIMO) transceiver arrangement 32 comprising at least four ports. The first and second directional antenna arrangements are connected to the four ports of the MIMO transceiver arrangement.

Description

ANTENNA SYSTEM

INTRODUCTION AND BACKGROUND

This invention relates to an antenna system and more particularly to an antenna system for a vehicle, such as a land-going or a water goingvessel, including a marine vessel.

It is imperative for marine vessels to remain connected to the outside world, as they traverse the oceans. Reliable broadband connectivity at sea could have a dramatic effect on the running costs of a vessel and could save time and money.

Reliability and efficiency of connectivity allow data collection and reporting systems to update data in real time over a network without human interaction. Such data may include data relating to fuel consumption, operating conditions and many other performance indicators which could then be controlled onboard or transmitted to shore. Safety is another important factor. Reliable and efficient connectivity allow the crew to stay in real time contact with land-based support and guidance. The vessel would be able to receive live reports on any hazardous conditions. Other reasons include crew welfare, less down-time, online training and attracting and retaining good crew members. The above points give a summarised, but clear indication as to why it is important to have a reliable broadband connection at sea. However, with current state of the art, broadband, including internet, connectivity at sea is not as efficient as at home, for example.

Most maritime antennas are normal omni-directional antennas i.e., they radiate their energy in all directions (360°), their gain is generally lower than that of directional antennas and their coverage distance is more limited. Once a vessel carrying such antennas leaves a harbour and travels out of coverage distance of cellular base stations on land, the vessel must rely on alternate ways for internet connection. One alternate way is via satellite and suitable antennas on the vessel. Communicating via satellite is currently not as effective as normal cellular communications. It is also extremely expensive to set up a satellite system and the users on board would have to use available data sparingly, as the data rates for satellite communications are very high.

Hence, there is a clear need for a system and method for increasing the range of a vessel’s communications system with land-based cellular base stations. OBJECT OF THE INVENTION

Accordingly, it is an object of the present invention to provide an antenna system with which the applicant believes the aforementioned disadvantages may at least be alleviated or which may provide a useful alternative for the known antenna systems.

SUMMARY OF THE INVENTION

According to the invention there is provided an antenna system comprising:

- an antenna carrier having a vertically extending carrier axis;

- a first directional antenna arrangement having first and second ports, the first directional antenna arrangement being mounted on the carrier such that a main axis of the first directional antenna arrangement extends in a first direction which is orthogonal to the carrier axis;

- a second directional antenna arrangement having first and second ports, the second directional antenna arrangement being mounted on the carrier such that a main axis of the second directional antenna arrangement extends in a second direction which is orthogonal to the carrier axis and angularly offset from the first direction;

- a multi-input and multi-output (MIMO) transceiver arrangement having at least first, second, third and fourth ports, the first and second ports being connected to the first and second ports of the first directional antenna arrangement and the third and fourth ports being connected to the first and second ports of the second directional antenna arrangement.

It is known that MIMO is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. The MIMO transceiver arrangement may comprise at least one MIMO router, also known as a MIMO modem, comprising MIMO technology. MIMO technology is known, is found in modern WI-FI routers and enables multiple antennas to send and receive spatial streams (multiple signals) simultaneously and to differentiate the signals sent to or received from different spatial positions. By leveraging technologies such as spatial multiplexing and space diversity, MIMO boosts the system capacity, coverage range, and SNR without consuming extra bandwidth. All wireless products with IEEE 802.11 n-2009 support MIMO.

The first directional antenna arrangement may be a first cross polarized directional antenna arrangement.

The second directional antenna arrangement may be a second cross polarized directional antenna arrangement. The antenna carrier may comprise at least a first axially extending part which may be polygonal in transverse cross section. The first polygonal part may comprise one of 3, 4, 5, 6 and more sides. Preferably, the first polygonal part is hexagonal and comprises 6 sides.

The first and second cross polarized directional antenna arrangements may be provided on first and second sides respectively of the first polygonal part.

Third to sixth cross polarized directional antenna arrangements may be provided on third to sixth sides respectively of the first polygonal part.

The antenna carrier may comprise a second axially extending part which may also be polygonal in transverse cross section. The second polygonal part may also comprise one of 3, 4, 5, 6 and more sides. Preferably, the second polygonal part is also hexagonal and comprises 6 sides.

The second polygonal part may be located axially adjacent the first polygonal part and radially or angularly offset relative to the first polygonal part. In a case where both the first polygonal part and the second polygonal parts are hexagonal, the second hexagonal part may be 30 degrees offset relative to the first hexagonal part.

Seventh to twelfth cross polarized directional antenna arrangements may be provided on the first to sixth sides respectively of the second polygonal part.

Each of the first to sixth cross polarized directional antenna arrangements may be vertically and horizontally polarized.

Each of the seventh to twelfth cross polarized directional antenna arrangements may be polarized at 45 degrees from the vertical and horizontal.

The MIMO may be nxn MIMO, wherein n = 1 , 2, 3, 4, 5, 6, 7, 8.... Alternatively, the MIMO may be MxN MIMO, where M + N.

The MIMO transceiver arrangement may comprise at least two 2x2 MIMO transceivers or at least one 4x4 MIMO transceiver.

Other combinations of 2x2 and/or 4x4 or higher order MIMO transceivers may also be utilized. The MIMO transceiver arrangement may comprise six 4x4 MIMO transceivers which may be connected to the first to twelfth cross-polarized directional antenna arrangements in any one of a number of different connection configurations.

The antenna system may further comprise a load balancer which is connected between the MIMO transceiver arrangement and a communications network of a host vehicle, for example.

The antenna carrier may be mounted on the vehicle to be stationary relatively to the vehicle.

Examples of the directional antenna arrangements are disclosed in the applicant’s international application PCT/IB2020/057763 entitled “Broad Band Directional Antenna” and the applicant’s ZA provisional application ZA2022/02053 entitled “Broad Band Directional Antenna”, the contents of which are incorporated herein by these references.

The vehicle may be a marine vessel and the invention includes within its scope a marine vessel comprising an antenna system as defined above. BRIEF DESCRIPTION OF THE ACCOMPANYING DIAGRAMS

The invention will now further be described, by way of example only, with reference to the accompanying diagrams wherein: figure 1 is a diagrammatic representation of a host marine vessel carrying an example embodiment of an antenna system; figure 2 is an isometric view of the antenna system comprising a dome; figures 3(a) and 3(b) are high level diagrams of basic example embodiments of the antenna system. figure 4 is a view similar to figure 2, but with the dome removed for better clarity; figure 5 is a section on line V in figure 4; figure 6 is a diagram illustrating an example embodiment of the connection of a first 4x4 MIMO transceiver to antenna arrangements of the antenna system; figure 7 is similar to figure 6, but with six(6) 4x4 MIMO transceivers connected to antenna arrangements of the antenna system; and figure 8 is another diagram illustrating the 4x4 MIMO transceivers and antenna arrangements of figure 7 connected via a load balancer to a communications network of the host marine vessel. DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

A marine vessel carrying and example embodiment of an antenna system 10 is generally designated 12 in figure 1. The antenna system 10 is connected to a communications network 14 (shown in figure 7) of the host marine vessel 12.

Referring firstly to figure 4, the antenna system 10 comprises an antenna carrier 16 having a vertically extending carrier axis 18. A first directional antenna arrangement 20 having first and second ports 22.1 and 22.2 (shown in figures 3(a) and (b)) is mounted on the carrier such that main axis 24 of the first directional antenna arrangement 20 extends in a first direction A (best shown in figures 4 and 5) which is orthogonal to the carrier axis 18. A second directional antenna arrangement 26 having a first port 28.1 and a second port 28.2 (also shown in figures 3(a) and (b)) is mounted on the carrier such that a main axis 30 of the second directional antenna arrangement 26 extends in a second direction B which is orthogonal to the carrier axis 18 and angularly or radially offset from the first direction A. Referring to figures 3(a) and (b), the antenna system 10 comprises a multi-input and multi-output (MIMO) transceiver arrangement 32 having at least first, second, third and fourth ports 34.1 to 34.4. The first and second ports 34.1 and 34.2 are connected to the first and second ports 22.1 and 22.2 of the first directional antenna arrangement 20 and the third and fourth ports 34.3 and 34.4 are connected to the first and second ports 28.1 and 28.2 of the second directional antenna arrangement 26.

In the example embodiment shown in figures 2, 4, 5, 7 and 8, the antenna system 10 comprises a dome 36 which houses the carrier 16, first to twelfth antenna arrangements 20, 26, 38, 40, 42, 44, 46, 48, 50, 52, 54 and 56 mounted on the carrier (as will be described in more detail below), the MIMO transceiver arrangement comprising six 4x4 MIMO transceiver devices 58, 60, 62, 64, 66 and 68 connected to the antenna arrangements (as will also be described below) and a load balancer 70 (shown in figure 8) connected between the MIMO transceiver arrangement 58 to 68 and the vessel communications network 14.

As best shown in figure 4, the carrier 16 comprises a first axially extending part 16.1 which is polygonal in transverse cross-section, preferably hexagonal with six equi-dimensioned sides. The carrier further comprises a second axially extending part 16.2 which is also polygonal in transverse cross-section, preferably also hexagonal with six equi-dimensioned sides. In a case where both the first polygonal part and the second polygonal parts are hexagonal, the second hexagonal part 16.2 may be 30 degrees offset relative to the first hexagonal part 16.1 . The first to sixth cross-polarized directional antenna arrangements 20, 26, 38, 40, 42 and 44 are mounted on the first to sixth sides respectively of the first hexagonal part 16.1. Similarly, seventh to twelfth cross-polarized directional antenna arrangements 46, 48, 50, 52, 54 and 56 are mounted on the first to sixth sides respectively of the second hexagonal part 16.2.

As best illustrated in figures 4, 6, 7 and 8 each of the first to sixth cross polarized directional antenna arrangements 20, 26, 38, 40, 42, 44 are vertically and horizontally polarized. Each of the seventh to twelfth cross polarized directional antenna arrangements 46, 48, 50, 52, 54 and 56 are polarized at 45 degrees from the vertical and horizontal.

In one example embodiment, the first to twelfth antenna arrangements 20, 26, 38, 40, 42, 44 and 46 to 56 may be connected to the first to sixth 4x4 MIMO transceivers 58, 60, 62, 64, 66 and 68 as illustrated in figures 6 and 7, which are self-explanatory. The skilled person will appreciate that in other example embodiments, other connection configurations are also possible.

The cross-polarized directional antenna arrangements may be of the kind described in the applicant’s international application PCT/IB2020/057763 entitled “Broad Band Directional Antenna” or applicant’s ZA provisional application ZA2022/02053 entitled “Broad Band Directional Antenna”, the contents of which are incorporated herein by these references.

It is well known that directional antennas focus their radiated energy predominantly in a direction of the main axis, giving them much higher gain in that direction and the ability to provide coverage over a longer distance in that direction.

The above directional, high gain antenna arrangements operate in the cellular band from about 617 to about 7200 MHz. The antennas of the arrangements are cross polarised to provide signal decorrelation and improved performance.

With the above configuration of the antenna carrier 16, and as best illustrated in figure 1 , the twelve antenna arrangements are directed such that respective adjacent main axes are angularly offset by about 30 degrees from one another, which provides substantially omni-directional coverage with increased coverage distance at least along the main axes, compared to the known omni-directional antennas.

By increasing the cellular coverage distance of a vessel with the antenna system 10, the need and time required for satellite communications will be reduced, thereby significantly reducing operating costs. As explained above, the system 10 may accommodate six transceivers 58, 60 to 68 and twelve antenna arrangements 20, 26, 38, 40, 42, 44 and 46 to 56 connected to the transceivers within the dome 36. The six transceivers are then connected to a load balancer 70, to achieve seamless communication transition between the six transceivers. The load balancer ensures efficient distribution of network traffic across the multiple transceivers. Effectively, they reduce transceiver response time and increase throughput for maximum performance.

Referring to figure 1 , as a vessel 12 is out at sea and cruising along the coastline 80, the system 10 would detect various cellular base stations 82 and 84 it will be able to connect to. The transceivers are in continual communications with the various base stations along the coast, to determine which would provide the best possible connection. Once a transceiver has connected with a base station, it must connect a SIM card of the specific transceiver to a specific service provider (utilizing the base station) and establish a secure connection. Once a secure connection has been established, the transceiver with the stronger or best connection is assigned by the load balancer as the main transceiver connection, while the other transceivers may act as diversity or redundancy transceivers.

As the vessel cruises along the coastline and the performance and connection stability between the various transceivers change or differ, a constant connection to the network must be maintained. The load balancer allows for seamless transition between the transceivers and which would result in increased throughput for better performance.

Claims

1. An antenna system comprising:

- an antenna carrier having a vertically extending carrier axis;

- a multi-input and multi-output (MIMO) transceiver arrangement having at least first, second, third and fourth ports, the first and second ports being connected to the first and second ports of the first directional antenna arrangement and the third and fourth ports being connected to the first and second ports of the second directional antenna arrangement. The antenna system of claim 1 wherein the first directional antenna arrangement is a first cross polarized directional antenna arrangement. The antenna system of any one of claim 1 and claim 2 wherein the second directional antenna arrangement is a second cross polarized directional antenna arrangement. The antenna system of any one of claims 1 to 3 wherein the antenna carrier comprises at least a first axially extending part which is polygonal in transverse cross section. The antenna system of claim 4 wherein the first part is hexagonal in transverse cross section and comprises 6 sides. The antenna system of any one of claim 4 and 5 wherein the first and second cross polarized directional antenna arrangements are provided on first and second sides respectively of the first part. The antenna system of claim 6 wherein third to sixth cross polarized directional antenna arrangements are provided on third to sixth sides respectively of the first part. The antenna system of any one of claims 4 to 7 comprising a second axially extending part which is polygonal in transverse cross section. 17 The antenna system of claim 8 wherein the second polygonal part is hexagonal in transverse cross section and comprises 6 sides. The antenna system of any one of claim 8 and claim 9 wherein the second polygonal part is located axially adjacent the first polygonal part and radially or angularly offset relative to the first polygonal part. The antenna system of claim 10 wherein the second polygonal part is 30 degrees offset relative to the first polygonal part. The antenna system of any one of claims 9 to 11 wherein seventh to twelfth cross polarized directional antenna arrangements are provided on first to sixth sides respectively of the second polygonal part. The antenna system of any one of claims 7 to 12 wherein the first to sixth cross polarized directional antenna arrangements are vertically and horizontally polarized. The antenna system of claim 13 wherein each of the seventh to twelfth cross polarized directional antenna arrangements are polarized at 45 degrees from the vertical and horizontal. The antenna system of claim 3 wherein the MIMO transceiver arrangement comprises two 2x2 MIMO transceivers which are 18 connected to the first and second cross-polarized directional antenna arrangements, respectively. The antenna system of claim 3 wherein the MIMO transceiver arrangement comprises one 4x4 MIMO transceiver which is connected to the first and second cross-polarized directional antenna arrangements. The antenna system as claimed in any one of claims 12 to 16 wherein the MIMO transceiver arrangement comprises six 4x4 MIMO transceivers which are connected to the first to twelfth crosspolarized directional antenna arrangements. The antenna system of any one of claims 1 to 17 comprising a load balancer which is connected between the MIMO transceiver arrangement and a communications network of a host vehicle for the antenna system. The antenna system of claim 18 wherein the antenna carrier is mounted on the vehicle to be stationary relatively to the vehicle. A marine vessel comprising an antenna system as claimed in any one of claims 1 to 19.