GB2578597A

GB2578597A - Vehicle spoiler assembly

Info

Publication number: GB2578597A
Application number: GB1817797.2A
Authority: GB
Inventors: Kayali Hassan
Original assignee: Dyson Automotive Research and Development Ltd
Current assignee: Dyson Automotive Research and Development Ltd
Priority date: 2018-10-31
Filing date: 2018-10-31
Publication date: 2020-05-20
Also published as: WO2020089584A1; GB201817797D0

Abstract

A spoiler 101 has a spoiler housing and a plurality, for example four or more, antenna elements 405-1, 405-2, 405-3, 405-4 which project downwardly relative to a surface (for example an inner surface) of the housing. The antenna elements preferably form a multiple-input, multiple-output (MIMO) array and may be cellular antennas, for example 2G, 3G, 4G or 5G, or alternatively may be V2X or global navigation satellite system (GNSS) antennas. The elements may be patch antenna or printed circuit board (PCB) elements. Typically the antenna elements are laterally spaced and vertically oriented. A preferred embodiment has antenna elements projecting from an upper portion to a lower portion, where the lower portion is a downward-facing fin.

Description

VEHICLE SPOILER ASSEMBLY

Field of the Invention

The present invention relates to a spoiler assembly for a vehicle. Aspects of the invention also relate to a vehicle having a spoiler assemhly.

Background of the Invention

Motor vehicles increasingly require advanced data communication capabilities. Data throughput and signal integrity is thus of particular importance given the large amounts of data expected to be received and transmitted. For example, navigation, voice communication, multimedia and cellular data may all need to be received and/or transmitted by the vehicle systems. With this in mind, conventional communication systems for motor vehicles typically use an antenna located on the roof of the vehicle and enclosed in a protective housing. The antenna is connected to a radio unit located about the cockpit of the vehicle using radio frequency (RF) coaxial cable. The radio unit contains the necessary electronics for demodulating and processing the RF signal received by the antenna and providing a signal output (e.g. data or audio) to vehicle systems. For example, the radio unit may include a receiver for demodulating the signal and other circuitry for processing the demodulated signal to provide a useable signal output. This arrangement allows for the antenna to he advantageously located in an external housing on the roof of the vehicle to provide good signal reception. The antenna housing protects the antenna and may be manufactured to provide transparency to radio frequency signals.

Summary of the Invention

The present invention provides a spoiler assembly for a vehicle, said assembly comprising a spoiler housing, a plurality of antenna elements, wherein the plurality of antenna elements are arranged to project downwardly with respect to a surface of the spoiler housing.

Locating an antenna on the roof of the vehicle in the conventional manner requires a shark-fin type enclosure in order to effectively protect and hide from view the antenna. Such enclosures inevitably have a detrimental effect on the aerodynamics of the vehicle, however. Further, the high data rates required by 4G/5G communication protocols may require multiple antennas. In addition, reception of satellite antennas also benefit from being located on the roof. Having more than one cellular or satellite antenna requires either that the shark fin is increased in size or multiple roof-top antenna enclosures are provided. This has the undesirable effect of further degrading the aerodynamic performance of the vehicle. Further, a shark fin type enclosure is unsightly and poses a design challenge in order for it to not impinge on the aesthetics of the vehicle appearance. Despite attempts to make them pleasing to the eye, shark fin-shaped enclosures on the roof are still visually obtrusive to the detriment of the appearance of the vehicle. Further, if the antennas are placed in a less obtrusive place such as in another external component such as the wing minors, bumper or under the roof then the reception is to some extent compromised and the attenuation problem with coaxial cable is exacerbated. In addition, such locations do not have sufficient volume for optimally configuring an antenna assembly. In the case of an under roof arrangement, to provide the necessary space for an effective antenna assembly would unacceptably compromise the headroom of the vehicle. It also forces a plastic and/or glass roof cover to he used which is detrimental to the mechanical properties of the vehicle.

Having plurality of antenna elements projecting downwardly with respect to the spoiler housing allows the antennas to be suitably configured to provide the necessary data throughput and bandwidth requirements required of modern communication standards such as cellular (e.g. 2G, 3G, and 4G (LTE) and 5G), GNSS and V2X with little or no aerodynamic penalty that would otherwise be incurred if the antennas were arranged elsewhere on the vehicle, for example in a conventional roof-top enclosure. Further, this arrangement allows high data throughput and connectivity to be achieved without compromising the cabin space or the appearance of the vehicle. In another embodiment, the V2X antenna is for V2V and is compliant with dedicated short-range communications standards such as IEEE 802.11p.

For example, the antenna elements may be configured as an antenna array which allows spatial and temporal multiplexing of received and transmitted signals. In embodiments, the antenna elements are advantageously configured as a Multiple Input Multiple Output (MIMO) array. In embodiments, the number of antenna elements is four or greater than four. This provides the minimum recommended number of antenna elements for advanced 4G and 5G data applications which require high data throughput. For 5G, for example, it is proposed to use the massive MIMO antenna diversity scheme. Including even more antennas increases the reception diversity further and allows even higher rates of data transmission and reception and enablement of beam forming. For example, in some embodiments, the antenna elements arc configured to perform adaptive beamforming, for example, to increase antenna gain where the directivity of a received/transmitted signal has been determined.

Preferably each of the antenna elements are connected to a first transceiver located in a vehicle. The antennas and transceiver act together to receive and transmit signals of a particular type e.g. where the antenna elements arc cellular antennas (2G, 3G, 4G (LTE), 5G), GNSS or V2X antennas. In another embodiment, the V2X antenna and transceiver are for V2V and is compliant with dedicated short-range communications standards such as IEEE 802.11p.

Such antenna elements or antennas may be vertically oriented to match the vertical polarization of the transmitter/receiver at a base station or satellite in communication with the vehicle in order to optimise signal reception. In these circumstances, the downward projection is particularly advantageous because it allows the antennas to extend into an inconspicuous space without significant aerodynamic penalty which would be incurred by conventional roof top antenna assemblies. This is particularly true if wide bandwidth reception is required because the required antenna length is proportional to the lowest wavelength that is required to be received and/or transmitted.

The antenna elements may be laterally spaced within the spoiler housing to efficiently use the full width of the spoiler and to provide the necessary spacing for spatial decorrelation between the received/transmitted signals at the antenna elements.

The antenna elements are preferably disposed within the spoiler housing and configured to project downwardly with respect to an inner surface of the spoiler housing. For example, the inner surface might he an upper (or uppermost) aerodynamic surface of the spoiler housing.

Advantageously, the spoiler housing may include an upper portion and a lower portion and the antenna elements are arranged to project downwardly from the upper portion to the lower portion. Thus, the upper portion may include an aerodynamic spoiler surface and the lower portion configured to house at least part of the downward antenna elements. Advantageously, the lower portion is a downward facing antenna fin to provide a pleasing vehicle aesthetic that is not detrimental to the aerodynamics of the vehicle. The downward fin may extend only partially across width of the upper aerodynamic portion, e.g. across a central portion, in order to minimise mass and may be configured to have only the volume necessary to house the downward antenna elements.

In other embodiments, the antenna elements are configured to project downwardly from a lower surface of the upper portion. In this way, the upper and lower portions may be conveniently designed and/or manufactured separately. For example, the upper portion may be designed purely based on aerodynamics which the lower portion is designed for holding the antennas. The upper portion and the lower portion may be isolated from each other, which again can simplify manufacture and also permits the thermal, electromagnetic and mechanical properties of lower portion to be designed solely based on the design requirements for the antenna elements and their assembly.

In another aspect of the present invention, there is provided a vehicle including a spoiler assembly as hereinbefore described. Preferably, the vehicle includes a transceiver coupled to the antenna elements. The transceiver may be included in the spoiler housing or located elsewhere in the vehicle.

Advantageously the vehicle may be provided with a data network, and the transceiver is configured to send and receive signals via the data network. Not only does the use of a vehicle data network allow the communications signals received and transmitted via the transceiver to be integrated with the other electronic systems on the vehicle but it permits the use of network cabling (e.g. Ethernet or Broad-R-Reach cabling) to be used to carry data signals to and from the transceiver. This is advantageous because the transceiver may be located proximal to the antenna elements and the transceiver connected to an infotainment or head unit using the network cabling. Thus, the amount of RF coaxial cabling used in connecting the antennas to the transceiver may be made small. The network cabling used to connect to the other vehicle systems is smaller and cheaper than the equivalent RE coaxial cabling and does not suffer from signal attenuation like RF signals and particularly high frequency cellular communication signals.

The vehicle may include a head (infotainment) unit configured to send and receive signals to and from the transceiver. The head unit may comprise an electronic control unit for transmitting and receiving signals to and from the transceiver. The head unit may be located in the vehicle cabin and, for example, about the instrument panel, centre console or an over-head unit whereas the transceiver may be located in proximity to the antennas in order to minimise the amount of RF coaxial cable used. Different functions of the infotainment unit such as digital radio, GPS, or cellular data may obtain the necessary cellular and GPS data across the network from the radio unit. Thus, a multi-functional infotainment unit is made possible within the vehicle.

Advantageously, the vehicle may include a wired Ethernet connection between the head unit and the transceiver. Ethernet cabling is particularly light and cheap and provides a 30 robust data connection from the spoiler radio unit and the head unit elsewhere in the vehicle. In principle, however, a wireless connection could be provided from the transceiver to the head unit (infotainment unit), for example using the WiFi standard, if appropriately configured WiFi transceivers were provided at both the head unit and coupled to the transceiver. Preferably, an Ethernet switch is provided in the vehicle to route signals between the head unit and the transceiver in order to integrate the head and radio units with the other electronic systems (e.g. ECUs) in the vehicle.

Brief Description of the Drawings

In order that the present invention may be more readily understood, embodiments of the invention will now he described, by way of example, with reference to the 10 accompanying drawings, in which: Figure 1 is an illustrative view of a vehicle including a spoiler assembly according to the present invention; Figure 2 is a top-down view of the vehicle showing schematically a spoiler housing having a radio module and antenna assembly disposed therein; Figure 3 is a schematic showing an integrated radio module incorporated into the spoiler in an embodiment of the present invention; Figure 4 is an overhead view showing the components of the spoiler assembly in an embodiment; Figure 5 shows a view of the spoiler housing from a perspective viewpoint; Figures 6a. 6b and 6c show a side view cross-sections of a spoiler assembly when viewed from left-to-right in respective embodiments of the invention; Figures 7a and 7b show different spoiler housing configurations for a spoiler assembly 30 according to embodiments of the invention; Figure 8 shows an embodiment in which the radio unit is enclosed within circuit housing located within the spoiler; Figure 9 shows an embodiment in which downwardly pointing antennas are located in a spoiler housing and a radio unit is located elsewhere; and Figure 10 shows a spoiler assembly in an embodiment having a spoiler hous g containing a downwardly protruding antenna array of antenna elements.

Detailed Description of the Invention

The vehicle 100 in Figure 1 is a motor vehicle that includes a rear spoiler 101 mounted at the rear of the vehicle and extending from the roof of the vehicle to provide an aerodynamic surface substantially aligned with the roof of the vehicle to provide a continuous surface. A lateral axis 102 and a longitudinal axis 103 of the vehicle are indicated as shown and references to the lateral and longitudinal axes herewith are with respect to these axes of the vehicle. Although, a motor car is shown, the invention is applicable to other types of motorised vehicle that utilise a spoiler.

As shown in Figure 2, a radio unit 201 and an antenna assembly 202 are located within the rear spoiler 101. The antenna assembly includes one or more antennas coupled to the radio unit 201 which includes respective receivers (receiving means) for demodulating signals received from the one or more antennas. Further, the radio unit 201 is configured so as to process the demodulated signals to provide an output data signal (signal processing means). The output data signal is provided to network cable 203 for transmission to a head unit 204 located about the dashboard 205 in the cabin 206 of the vehicle 100. The head unit 204 preferably includes a digital signal processor for processing digital signals such as those received via the network cable 203 and a wireless connectivity module.

The term "radio unit" is used throughout this description; however, it will be appreciated that the expression 'communication unit" or "communication module" could also he used.

The one or more receivers may also each function as a transmitter i.e. a transceiver and thereby be further operable to modulate data signals for transmission via the antenna(s) in addition to demodulation of received signals.

Preferably, the signals from the radio unit 201 conform to the Ethernet standard (10BASE-T, 100BASE-TX, 1000BASE-T, for example) and the cabling is Cat 5,5E, 6 cabling. Preferably, the BroadR-Reach automotive Ethernet standard is used both in transmission and reception of signals between the radio unit 201 and the head unit 204 and the network cabling 203 consists of unshielded single twisted pair cabling. Advantageously, this provides a robust and efficient signalling scheme for automotive systems. However, as will be appreciated by those skilled in the art, other types of cabling suitable for network data transmissions may also be used. For example, other types of shielded or unshielded twisted pair, fiber-optic or even coaxial cable (despite the aforementioned disadvantages) could be used to provide the data connection between the radio unit and the head unit. Alternatively, each of the radio unit 201 and the head unit 204 may he furnished with a WiFi transceiver and so that the radio unit and the head unit may communicate wirelessly. This has the advantage of foregoing the need for any associated network cabling, thus reducing the mass of the vehicle further.

Advantageously, an Ethernet switch 207 may be provided between the radio unit 201 and the head unit 205. The Ethernet switch 207 is configured to control data communications between the various systems (not shown) of the vehicle and provide security and diagnostic functions. In addition, the radio unit 201 may he arranged to provide and/or receive different digital signal types. In this embodiment, the radio unit 201 is also capable of transmitting and receiving an A2B (Automotive Audio Bus (RTM)) digital signal to and from an overhead unit 208 provided in the cabin via cabling 209. The A2B cabling 209 may be used to transport critical digital audio to and from the radio unit 201 via the antenna assembly. In an embodiment, the overhead unit 208 includes occupant controls for generating an eCall request, for example, which is transmitted to the radio unit via the A2B connection 209.

Figure 3 shows an embodiment in which the radio unit 201 of Figure 2 includes a plurality of receivers. These include an SDARs 301-1, GNSS 301-2, V2X 301-3 and an LTE 301-4 receiver. Corresponding SDARs 302-1, GNSS 302-2, V2X 302-3 and LTE 302-4 antennas are provided which are coupled to a respective one of the receivers 3011, 301-2, 301-3, 301-4. These antennas may he any configuration of antenna that is suitable for receiving and transmitting signals in the bandwidth applicable for the respective function. The antennas may be PCB or patch antennas, for example, and one or more may be located separately from the radio unit or may be integrated in a circuit hoard with the modules of the radio unit 201. Each patch antenna may he formed by a patch or area of conductive material on a substrate. Typically, the patch antenna may he rectangular but this is not necessarily the case. Other shapes are possible, such as a polygonal shape, a T-shape, an L-shape etc. The antennas may he vertically oriented with respect to the spoiler assembly when installed on a vehicle. For example, the antenna surface may be perpendicular to a surface of the spoiler assembly such as an inner wall of the spoiler housing, the plane in which the radio unit 201 is secured or a lower surface of the spoiler housing. Generally, the orientation of the antennas is configured to match the orientation of the transmission antennas, i.e. at a base station or the satellite. For example, satellite broadcast and transmission systems would typically be circularly polarized making a patch antenna suitable for communication and cellular base station aerial would be vertically polarized making a vertically oriented antenna a

suitable choice.

The LTE (Long Term Evolution)/4G antenna 302-4 may comprise an array of antennas arranged in so as to provide spatial diversity including MIMO (multiple-input and multiple-output) functionality to improve data throughput. That is, where one or more of the antennas in the array is used to transmit data and another is used to transmit data.

Further, the signal to noise ratio of the antenna may he improved. Such an arrangement is shown in Figure 4 and will be explained in more detail below. The LTE antennas are used for telecommunications in a 4G telecommunications band, for example, with a highest frequency of 2.60-1z. In this embodiment, an LTE/4G antenna (or antenna array) and transceiver is shown but other cellular telecommunications bands could be used such as 2G, 3G and 5G.

In this embodiment, the antennas 302-1, 302-2, 302-3 and 303-4 are located within the spoiler and are either connected to the radio unit by a short length of coaxial cable or arc formed directly on a PCB with the other circuit elements of the radio unit 201. Because the antennas and radio unit are proximate within the spoiler area, the lengths of coaxial cable is short and signal attenuation from antenna to the radio unit is negligible.

Where a receiver relates to a communications function such as GNSS 301-2, V2X 3013, or 4G/LTE 301-4, two-way (duplex) data communication (transmission and reception) is desirable. Accordingly, the receiver will preferably also include a transmission function so that these modules are transceivers. The SDA Rs receiver 3011 is for broadcast reception of digital radio signals so typically only the ability to demodulate received signals is required. Other broadcast antenna and receiver pairs may also he used such as for DAB reception.

The receivers/transceivers 301-1, 301-2, 301-3, 301-4 are connected to a processor 303 which is further connected to Ethernet interface 305. The processor is configured to provide a gateway function that takes the demodulated digital signals from the transceivers and package the data contained for transmission via the Ethernet interface 305. The processor 303 is also capable of receiving data requests via the Ethernet interface 305. Other functions that may be provided are diagnostic and security functions, such as encryption or decryption of data that is to be transmitted and received within the car. For example, a cryptographic key system may be used for transmissions in the vehicle data network to protect communications between vehicle systems from being intercepted and manipulated by third parties. In effect, the processor can provide some of the functionality of an Ethernet hub or gateway controlling the flow of data signals between the components of the radio unit to and from the vehicle data network. The Ethernet interface is connected to the Ethernet switch 207 by the Ethernet connection 201 As shown, the Ethernet switch is connected to the Head unit 204. The Head Unit 204 in this embodiment is an infotainment unit which includes an audio module 311 and a connectivity module 310. The connectivity module provides Bluetooth and/or WiEi connectivity, for example, with mobile devices.

In addition, an A2B (Automotive Audio Bus (RTM)) master module 304 is provided which is capable of receiving and transmitting control and audio data signals from and to the LTE transceiver 301-4. The A2B master 304 is connected to a corresponding A2B slave module 306 in the overhead unit 208. The A2B connection uses unshielded 2-wire cabling and is thus lightweight and inexpensive compared to shielded digital audio cabling. The A2B slave 306 is connected to an audio unit 307 and a control unit 308. The control unit 308 generates control information based on user inputs received via the user controls on the overhead unit. In addition, the control unit 308 is operable to transmit and receive control data from other ECUs in the vehicle and in particular from an ECU 309 associated with a vehicle safety system. In an embodiment, the LTE transceiver 301-4 is further configured to function as an eCall module 312 for making emergency transmissions in the event of a crash event via a cellular connection. Thus, the A2B connection provides an effective means to transmit and receive digital audio for providing the eCall functionality. Further, by providing the eCall module 312 in the spoiler certain compliance criteria associated with protecting the eCall box in the event of a front, side or rear crash may be complied with. The eCall unit would otherwise have to be provided in a secure location under a vehicle seat to protect it in the event of a crash and then a wired connection provided to the head unit 204. By having the eCall function in the spoiler it is protected in the event of the most common crash events and RE coaxial connections from transmission/reception antennas are not needed. Thus, the need for a separate eCall box is avoided thereby reducing complexity, weight and cost of the vehicle assembly. Preferably, the radio unit 201 also includes a back-up battery unit to provide power to at least the eCall function in the event of the main supply failing or being unable to provide energy.

In the embodiment shown in Figure 3, both A2B and Ethernet are provided for but in certain embodiments the radio unit 201 may communicate with the automotive systems of the vehicle with only one of an Ethernet or A2B connection such that the processor or the A2B module are omitted from the radio unit.

In Figure 3, the receivers/transceivers 301-1, 301-2, 301-3 and 301-4 are shown as different elements in the schematic. However, in some embodiments at least some of the receiver/transceiver functions may he performed by a processor running an application stack. Further, some or all of the signal processing for providing a digital signal for a data network may be performed by a receiver/transceiver unit itself, forgoing the need for a separate processor. In other words, the receiver/transceiver may he both a signal processing means and a means for demodulating and/or modulating an RF signal. In the extreme, all of the functions of the modules of the radio unit may he performed by a single processor running multiple applications, an ASIC, FPGA or other circuit types or combinations of circuit types known to those in the art.

Figures 4, 5 and 6 show how a circuit and antenna assembly such as that shown in Figure 3 may he packaged as an assembly within a spoiler. Figure 4 shows the inside of the spoiler 101 from an overhead perspective, illustrating the layout of the components packaged therein. The illustrated assembly includes a printed circuit board 401 that carries a radio unit 201 and an antenna assembly 202 as per Figures 2 and 3. The PCB is secured to the inside of the spoiler housing via the mounting holes 410a, 410b, 410c and 410d.

Included on the PCB are a GNSS patch antenna 402 and an SDARS patch antenna 403 both of which are circularly polarized patch antennas formed on a substrate on the PCB. In contrast, a V2X antenna 404, also mounted on the PCB, is oriented perpendicular to the plane of the circuit board and aligned laterally to the vehicle. Perpendicular orientation is used for V2X transmission and reception in order to match the vertical polarization of the base station antennas. Other orientations of antennas are possible depending on the reception requirements for the signal type they are configured to receive.

Four LTE antennas 405-1, 405-2, 405-3, 405-4 are provided which are laterally spaced across lateral axis 102 so as to be spaced across the spoiler housing. The spacing between the LTE antennas is ideally arranged so that there is at least 10dB of decorrelation between the antennas and so that a multiple-input multiple-output configuration is possible. Thus, the space within the spoiler is optimally utilised to provide an LTE antenna array with high data throughput. Each of the antennas 405-1, 405-2, 405-3, 405-4 is a PCB-type antenna comprising a conductive layer arranged on a substrate and is oriented perpendicular to the plane of the main radio unit PCB 401. They are mounted by means of respective brackets which are fixed to an inner surface of the spoiler. The inner antennas 405-2 and 405-3 are configured to receive high frequencies. For example, for LTE/4G these antennas are configured to receive frequencies at 1.6 GHz and 2.1 GHz. The outer antennas 405-1 and 405-4 are L-shaped antennas, configured so as to receive low frequencies e.g 700MHz. The L-shaped configuration allows the additional length of PCB to allow reception of low frequencies in a space compact enough to fit within the spoiler housing. The LTE antennas 405-1 405-2, 405-3, 405-4 are connectable to the PCB circuit 401 by RE coaxial cabling (not shown) via the connectors 406.

Connectors 407-1 and 407-2 provide A2B and Ethernet connections respectively while connector 407-3 is a power supply connector. A further antenna coaxial connection 408 is provided which in this embodiment provides a connection to a further V2x antenna located elsewhere in the vehicle. This provides reception diversity with the on-board PCB antenna 404 which is has been found to be vulnerable to poor signal reception due to signal reflections in the spoiler cavity. The V2x antenna may he used for system critical communications and accordingly antenna diversity is appropriate. The signal transmitted to the coaxial connection 408 will be subject to some attenuation whereas the on-board antenna will not but the reception/transmission characteristics of the off-board V2x antenna may be better. In some circumstances the on-hoard antenna with no attenuation will provide the better signal whereas in others the off-board antenna with its better reception may be better. This arrangement, therefore, attempts to provide redundancy and a best of both worlds arrangement for V2x communications.

The receivers/transceiver 301-1. 301-2, 301-3, 301-4 and processor 303, 304 functions of the Figure 3 schematic are performed by number of IC chips/modules embedded and interconnected on the PCB 401. In this embodiment, a processor 412, and LTE 414, V2x 416, GNSS 418 transceiver IC chips/modules are provided together with and SDARs receiver chip/module 420 on the PCB 40L The LTE chip/module 414 in this embodiment provides both the A2B master and eCall functionality. As will be appreciated, conductive tracks and appropriately configured IC pins (not shown) will provide the connectivity shown in Figure 3.

Together, the integrated circuit modules provide the functionality of the system architecture shown in Figure 3. However, other combinations of hardware and software are possible that provide the same functionality of a receiver/transceiver for demodulating/modulating a signal and processing the signal to provide a digital signal output suitable for transmission on a data network. For example, a general purpose processor running a software stack to provide the required functionality or multiple receiver or transmission functions might he consolidated in one or more ICs.

The perspective illustration of Figure 5 and the side view of Figure 6a, showing a section view looking into the spoiler from left to right along the lateral axis 102, show how the LTE antennas 405-1, 405-2, 405-3 and 405-4 are disposed within the spoiler housing. As shown, a portion of each LTE antenna projects downwards into a lower portion 501 of the housing. As shown, the portion of the Antenna which projects downwardly from the PCB 401 is greater than portion extending above the PCB 401. The lower portion 501 in this embodiment takes the form of a single downwardly oriented antenna fin forming a portion of the housing. As shown, the laterally spaced antennas are generally aligned with the longitudinal axis 103 which is perpendicular to the lateral axis 102.

By having the vertically oriented antennas 405-1, 405-2, 405-3, 405-4 project downwardly with respect to an upper aerodynamic surface of the spoiler they can he kept out of view of an observer of the vehicle, thus making the vehicle appearance more attractive. By having the antennas project downwards, the forward reception will inevitably require signals to travel through the vehicle itself leading to some degradation in the forward antenna gain. However, this is mitigated, at least to some extent, because the antenna signals do not have to be carried as RF signals on coaxial cable a distance across the vehicle and can be carried instead as data signals on network cabling (or even transmitted wirelessly). In particular, as already discussed, because the radio unit 201 is located in the spoiler housing 101 together with the antenna assembly 202, data networking cable can be used to transport the data signals to a head unit 204 elsewhere in the vehicle. The trade-off between the improved aerodynamics and appearance with the detriment to the forward gain is thus made more acceptable.

In this embodiment, the lower portion 501 is integrally formed with the upper portion 502 of the spoiler housing 101. However, in other embodiments the spoiler housing may be formed of two distinct component parts. one comprising the upper portion 502 and the other the lower portion 501.

The arrangement of the four antennas 405-1, 405-2, 405-3 and 405-4 when configured in this manner is shown in Figure 7a in a rear view cut-away of the spoiler showing the under fin 701. In other embodiments the lower portion of the spoiler housing may comprise multiple fins each enclosing one or more antennas. An example is shown in Figure 7b where two downward fins 702a and 702b are provided. The first under-fin portion 702a encloses antennas 405-1. 405-2 and the second under-fin portion 702b encloses antennas 405-3 and 405-4. In a further embodiment, each downwardly projecting antenna may be enclosed in a different antenna fin such that the antennas arc isolated from each other. Other configurations of under-fins and antennas are also possible.

In the embodiment shown in Figure 5 and 6a, a portion of the antenna resides inside an upper portion of the housing 502. This has the advantage of making use of the available space in the aerodynamic part of the spoiler and minimising the space required by the lower portion 501 of the housing which may be detrimental to the overall weight and aerodynamic performance of the spoiler. However, in other embodiments the entirety of the antenna may project downwardly from or below a plane generally corresponding to a boundary between the upper and lower portion such that substantially the entirety of the vertically oriented antenna elements are contained within the lower portion.

For example, in the embodiment shown in Figure 6b, the lower portion comprises a downwardly extending antenna fin 601 that is isolated from the upper portion of the spoiler housing by mounting beneath a lower surface 602 of the upper portion 502 of the spoiler housing. One or more of the antennas may be enclosed entirely within the downward antenna fin 601 and are thus mounted beneath the upper portion of the spoiler housing 101. This has the benefit that those antennas in the under-fin portion 601 can be more easily accessed for maintenance and protected. Further, the material for the lower portion enclosing the downwardly extending antennas may be selected to minimise signal attenuation, such that the upper and lower portions may use different materials.

In the above embodiments the antennas 405-1, 405-2, 405-3, 405-4 are oriented vertically within the spoiler assembly but in other embodiments they may project generally downwardly by being oriented at an angle with respect to the vertical axis. This can assist in reducing the downward space required or fitting the antenna within a given geometry of the spoiler housing without unduly compromising antenna reception.

For example, Figure 6c shows an embodiment whereby the antenna is disposed at 45 degrees with respect to the vertical axis. This design freedom can assist in reducing the space required within the spoiler housing and for fitting the antenna within a given geometry of the spoiler housing without unduly compromising antenna reception i.e. due to the change in orientation.

Figure 8 illustrates how the PCB containing the circuit for the radio unit 201, and some of the antenna assembly 202, may be enclosed within a circuit housing 801 located within the spoiler housing 101. The housing contains a number of ports 802 aligned with the connectors on the PCB so that they may be accessed. Placing the PCB within a circuit housing allows mechanical protection and thermal management of the circuit therein. For example, the material of the circuit housing may he chosen for its mechanical and/or thermal properties and/or a heatsink fins or similar structure (not shown) may be provided with the housing to dissipate heat. This is particularly important given the circuit location in the spoiler where solar loading may increase the 10 thermal load upon the circuit and antenna package.

Figure 9 shows a further embodiment in which an antenna assembly 901 is located in the spoiler housing 101 and a transceiver circuit (transceiver) 902 for modulating and/or demodulating transmitted and received signals from the antenna assembly 901 is located outside of the spoiler housing 101. In particular, the transceiver circuit 902 is located near to the spoiler assembly at a location near the rear of the vehicle. Thus, the length of coaxial cable between the transceiver circuit 902 and the antenna assembly 901 may be made short and the attenuation small. The transceiver circuit 902 is connected to an Ethernet switch (network switch) 903 via Ethernet cabling (network cabling) 906 in a similar manner to the radio unit 201 which was described in the previous embodiments.

This architecture allows connection to for example infotainment systems in a head unit 904 located about the vehicle dashboard via a data network and without excessive signal attenuation due to RF cabling. The antenna assembly 901 contains a plurality of antenna elements which are preferably configured as an antenna array coupled to the transceiver circuit. The antenna elements may be suitable for any of the communication protocols already described and in particular may be cellular antennas for 4G and/or SG configured in a M IMO configuration.

Figure 10 shows an embodiment whereby the antennas are cellular antennas as per the 30 Figure 5 embodiment. Unlike Figure 5, however, the spoiler 1000 houses only the cellular antennas 1001-1, 1001-2, 1001-3, 1001-4 and not a radio unit 401 or receiver/transceiver circuitry. As explained with respect to Figure 9, the transceiver circuitry 902 in this embodiment is contained elsewhere in the vehicle but ideally still close enough to the antenna assembly that the amount of RE cabling is kept small. As mentioned above, the antennas may be configured as an array to increase data throughput, for example, by a MIMO configuration. This is particularly important for high data rate protocols such as 4G and 56 and potentially for future uses of V2X protocols. As will be appreciated further cellular antennas could be included in the spoiler housing to further increase the data throughput for such configurations without incurring any significant aerodynamic penalty for a vehicle. In addition, in embodiments the depth of the spoiler housing can be suitably increased to accommodate longer vertical antennas to provide greater signal bandwidth. In another application, the antennas may be configured to receive or transmit signals using a beam forming technique. This can he used for identification of the direction of a received signal and further to focus the directivity of antenna reception or transmission to improve antenna gain in that direction. The beamforming capabilities are improved with further antennas and thus the extra space made possible by having the antennas projecting downwardly from a surface of the spoiler can be usefully leveraged to provide these additional or improved functionalities without affecting the vehicle aerodynamics, for example.

Although the above embodiments concern an assembly involving four downwardly projecting antennas (antenna elements) within a spoiler housing, it will be appreciated that the invention is not limited to that number. Other numbers of downwardly projecting antennas may be provided with the advantages as set out above. Further, although the lower portion has been shown as a downward fin, it will be appreciated that other shapes are possible depending on the aesthetic, aerodynamic and volume requirements of the spoiler design.

Further, although the above embodiments show the radio unit (transceiver) circuitry as being either close to or within the spoiler housing, it is also possible to forgo some of the advantages of the invention by having the radio unit/transceiver comprise part of a head (infotainment unit) located conventionally about the vehicle cockpit.

Conventional RF coax cabling can be used to connect the spoiler antennas to the head unit. Thus, improvements in data throughput without aerodynamic penalty can be achieved albeit without the advantages of mitigating RE signal attenuation caused by the coaxial cable. The signal attenuation in such an embodiment might be mitigated in other ways, either by better quality cabling or by use of a beam forming of the antenna

array, for example.

In the above embodiments a V2X receiver/transceiver and associated antenna is described. V2X signal for transmission. In one embodiment, the V2X receiver/transceiver and antenna are for V2V (vehicle-to-vehicle) communications and arc compliant with a dedicated short-range communications (DSRC) standard such as IEEE 802.11p.

Claims

Claims 1. A spoiler assembly for a vehicle, said assembly comprising: a spoiler housing; a plurality of antenna elements; wherein the plurality of antenna elements are arranged to project downwardly with respect to a surface of the spoiler housing.
2. A spoiler assembly according to claim 1, wherein the antenna elements are configured as an antenna array.
3. A spoiler assembly according to claim 2, wherein the antenna elements are configured as a Multiple Input Multiple Output array (MIMO).
4. A spoiler assembly according to claim 3, wherein the number of antenna elements is four or greater than four.
5. A spoiler assembly according to claim 3, wherein the antenna elements are configured to perform adaptive beamforming.
6. A spoiler assembly according to any preceding claim, wherein the antenna elements are arranged to be connected to a transceiver located in a vehicle.
7. A spoiler assembly according to any preceding claim, wherein the antenna elements are cellular antennas.
8. A spoiler assembly according to any preceding claim, wherein the antenna elements arc one of 2G. 3G, 4G (LTE), 5G, GNSS or V2X antennas.
9. A spoiler assembly according to any preceding claim, wherein the antenna elements are PCB or patch antenna elements.
10. A spoiler assembly according to any preceding claim, wherein the antenna elements are vertically oriented within the spoiler housing.
11. A spoiler assembly according to any preceding claim, wherein the antenna elements are laterally spaced apart within the spoiler housing.
12. A spoiler assembly according to claim 11, wherein at least one antenna element is oriented so as to be generally aligned with an axis perpendicular to the lateral axis along which the antenna elements are laterally spaced apart.
13. A spoiler assembly according to any preceding claim, wherein the antenna elements are disposed within the spoiler housing and configured to project downwardly with respect to an inner surface of the spoiler housing.
14. A spoiler assembly according to claim 13, wherein the spoiler housing comprises an upper portion and a lower portion and the antenna elements project downwardly from the upper portion to the lower portion.
15. A spoiler assembly according to claim 14, wherein the lower portion is a downward facing antenna fin.
16. A spoiler assembly according to claim 15, wherein the upper portion and the lower portion are isolated from each other.
17. A spoiler assembly according to claim 16, wherein the antenna elements are configured to project downwardly from a lower surface of the upper portion.
18. A vehicle including a spoiler assembly according to any preceding claim.
19. A vehicle according to claim 18, further comprising a transceiver coupled to the antenna elements.
20. A vehicle according to claim 19, further comprising a data network, wherein the transceiver is configured to send and receive signals via the data network.
21. A vehicle according to claim 19 or claim 20 further comprising a head unit configured to send and receive signals to and from the transceiver.