[0001] The present invention relates to a vehicle, in particular a road vehicle, comprising
a system that is optimized for transceiving data and configured in particular to operate
in the 5G frequency band.
[0002] In the description that follows, by way of a possible example of a vehicle, reference
will be made to an automobile without thereby intending in any way to limit the realization
of the present invention in the form of other types of road vehicles, such as for
example buses, trucks, commercial vehicles, etc.
[0003] As is known, the use of so-called "infotainment" systems on board vehicles, such
as automobiles (or cars), is widespread. In fact, vehicles currently on the road integrate
many services ranging from entertainment, for example audio and/or television, to
telephony, to driving assistance, with a view to ensuring ever greater travel safety
and comfort for users.
[0004] Consequently, the data traffic that vehicles happen to be transceiving has assumed
ever increasing proportions, thus requiring the implementation of ever faster and
more reliable communication systems.
[0005] In this regard, vehicles are also impacted by the on board use of the most recent
so-called 5G communication system, to which millimeter-wave (mmW) frequency bands
have been allocated.
[0006] Clearly, for the appropriate functioning of the communications one of the fundamental
components for the proper transceiving of data is represented by antennas which are
usually subject to problems related to the attenuation of signals due to propagation
in free spaces or the presence of obstacles.
[0007] Such problems are particularly accentuated in the millimeter-wave frequency bands
and even more so in the case of vehicles where the structure of the vehicle itself
and the materials used, such as the metal bodywork, happen to be shielding. In these
conditions, depending on the installation of the antenna on a vehicle and its position
during travel, the quality of the data communication with the base radio stations
external to the vehicle may prove to be unsatisfactory or it may in any case be necessary
to adopt on board the vehicle antenna configurations that are as redundant as possible.
In the latter case, however, the overall cost of the communication systems increases,
in addition to there being installation problems, in particular on board automobiles
where the space available for the antennas is limited.
[0008] The main object of the present invention is to mitigate these problems, and in particular
to offer a solution that makes it possible to find an appropriate balance between
the requirement to adequately cover the signal transceiver field around the vehicle
and the need for an optimized number of antennas.
[0009] This main object, as well as any other objects which will emerge more clearly from
the description that follows, are achieved by a vehicle, in particular a road vehicle,
such as an automobile, as defined in claim 1.
[0010] Particular embodiments constitute the subject matter of the dependent claims, the
content of which is to be understood as an integral part of the present description.
[0011] Further characteristics and advantages of the invention will become apparent from
the detailed description that follows, set forth purely by way of non-limiting example,
with reference to the attached drawings, in which:
Figure 1 schematically illustrates one possible stratigraphic embodiment of a millimeter-wave
antenna installed on board the vehicle according to the present invention;
Figures 2 to 8 schematically illustrate portions of some layers that are usable in
the antenna shown in Figure 1;
Figure 9 schematically illustrates a block diagram of a data transceiver system installed
on board the vehicle according to the invention;
Figure 10 is a top view that schematically illustrates a vehicle according to the
invention;
Figure 11 is a detail that schematically illustrates a millimeter-wave antenna installed
in a headlight assembly of a vehicle according to the invention.
[0012] It should be noted that in the detailed description that follows, components that
are identical or similar, from a structural and/or functional standpoint, may have
the same or different reference numerals, regardless of whether they are shown in
different embodiments of the present invention or in distinct parts.
[0013] It should also be noted that, in order to clearly and concisely describe the present
invention, the drawings may not necessarily be to scale and some characteristic features
of the description may be shown in a somewhat schematic form.
[0014] Furthermore, where the terms "adapted", or "organised ", or "configured", or "shaped",
or " set ", or any similar term may eventually be used in the present document, with
reference being made to any component in its entirety, or to any part of a component
or a combination of components, it is to be understood that it refers to and correspondingly
includes the structure and/or configuration and/or form and shape and/or positioning.
[0015] In particular, when these terms refer to electronic hardware or software means, they
are to be understood as including circuits or parts of electronic circuits, as well
as software/firmware, such as for example algorithms, routines and programs in general,
that may be running and/or residing in any storage medium.
[0016] In addition, where the term "substantial" or "substantially" is used herein, it is
to be understood as including an actual variation of plus or minus 5% relative to
what indicated as the reference value, axis or position; and where the terms "transverse"
or "transversely" are used herein, they are to be understood as including a direction
that is not parallel to the reference part or parts or direction(s)/axes to which
they refer, and perpendicularity is to be considered as a specific case of transverse
direction.
[0017] Finally, in the description and in the claims that follow, the ordinal numerals first,
second, et cetera, will be used for purposes of illustrative clarity and in no way
should they be construed as limiting for any reason whatsoever; in particular, the
indication for example, of a "first layer", or of a first "first sublayer...", does
not necessarily imply the presence or the stringent requirement, in all the embodiments,
of a further "second layer" or "second sublayer" or vice versa, unless this presence
is clearly evident for the proper operation of the described embodiments, nor that
the order is to be identical to the sequence described with reference to the illustrated
exemplary embodiments.
[0018] Figure 10 schematically illustrates a vehicle according to the invention, indicated
by the reference numeral 100, in which a system for transceiving data is installed
on board the vehicle itself; an exemplary embodiment of this system for the transceiving
of data is illustrated in Figure 9 and indicated therein by the overall reference
numeral 200.
[0019] Usefuly, the system 200 installed on board the vehicle 100 comprises at least one
first set of millimeter-wave antennas 1 for the transceiving of data in the 5G frequency
band, in particular with frequencies equal to or greater than 20 Ghz and up to 100
GHz, and in which, with respect to an imaginary first plane E and an imaginary second
plane F that are perpendicular to each other and that virtually divide the vehicle
100 into four quadrants A, B, C, D, the said at least one first set of millimeter-wave
antennas 1 comprises at least four antennas 1, which are each installed in a corresponding
quadrant of the said four quadrants A, B, C, D, and an embodiment of which is illustrated
in Figures 1-8.
[0020] Depending on the dimensions of the vehicle, these four quadrants A, B, C and D may
be substantially identical to or different from each other, and the planes E and F
are to be considered to be drawn, for example, in a manner such as to include the
two corresponding direct centre-line axes one along the line joining front-rear of
the vehicle, and the other along the line joining the lateral sides of the same.
[0021] In any case, at least the two front quadrants A and B are to be considered identical
to each other and the two rear quadrants C and D are also to be considered identical
to each other.
[0022] The millimeter antennas 1 may be substantially identical to each other or, depending
on the requirements, it is possible to simultaneously use millimeter antennas that
are different from each other in construction.
[0023] In particular, and as will become apparent in more detail from the description that
follows, at least one of the four millimeter-wave antennas 1 used, preferably each
of them, comprises at least one radiating element 14, and is arranged in the respective
quadrant A, B, C, D in a manner so that between the at least one radiating element
14 and the surface external to the vehicle 100 towards which irradiation is to occur
or from which signals are to be received, there are interposed one or more surfaces
of non-metallic material and having a coefficient of loss (also referred to as dissipation
factor "tan δ" and equal to the ratio between the active power and reactive power
absorbed by the material) lower than 0.1.
[0024] In one possible embodiment, at least one of said four millimeter-wave antennas 1
is arranged to be coincident with a left front headlight or headlight assembly 101
or right front headlight or headlight assembly 102, or with a left rear taillight
or taillight assembly 103 or right rear taillight or taillight assembly 104.
[0025] In one possible embodiment, at least one of the said four millimeter-wave antennas
1 is arranged to be coincident with one of the front or rear doors 112 of the vehicle
100. In this configuration, the at least one antenna 1 may be integrated into the
structure of a side bumper 109 (emphasized in Figure 10 for greater clarity of illustration)
applied externally to the corresponding door 112, or may be arranged in the interspace
defined between a side bumper 109 and the associated door 112.
[0026] In particular, according to one possible embodiment illustrated in Figure 10, among
the four antennas 1: a first antenna 1 is arranged to be coincident with a left front
headlight 101 or left front headlight assembly 101 of the vehicle 100; a second antenna
1 is arranged to be coincident with a right front headlight 102 or right front headlight
assembly 102 of the vehicle 100; a third antenna 1 is arranged to be coincident with
a left rear taillight 103 or left rear taillight assembly 103 of the vehicle 100;
and a fourth antenna 1 is arranged to be coincident with a right rear taillight 104
or right rear taillight assembly 104 of the vehicle 100.
[0027] Alternatively, according to one possible embodiment represented in Figure 10 with
broken lines, among the four antennas 1, for a vehicle 100 equipped with four side
doors 111, a first antenna 1 is arranged to be coincident with a side bumper 109 mounted
on the left front door 112; a second antenna 1 is arranged to be coincident with a
side bumper 109 mounted on the right front door; a third antenna 1 is arranged to
be coincident with a side bumper 109 mounted on the left rear door 112; and a fourth
antenna 1 is arranged to be coincident with a side bumper 109 mounted on the left
front door 112.
[0028] Clearly, in the vehicle 100 according to the invention it is possible to implement
a combined configuration in which, among the four millimeter-wave antennas 1, one
or more antennas 1 are mounted to be coincident with headlights or headlight assemblies,
and one or more of the remaining antennas 1 are mounted to be coincident with side
bumpers 109.
[0029] A preferred embodiment of at least one of the millimeter-wave antennas 1 is illustrated
in Figures 1-8.
[0030] In particular, the antenna 1 comprises a containment casing, schematically illustrated
in Figure 1 by the reference numeral 2, which houses inside it all or at least part
of the components of the antenna. This containment casing 2 is for example made of
plastic material and is conveniently mounted integrated on the reflector of a corresponding
front headlight or headlight assembly, or rear taillight or taillight assembly of
the vehicle 100, for example as illustrated in Figure 11 for the right front headlight
assembly 102.
[0031] In this possible embodiment, the antenna 1 may be substantially integrated into the
structure of the associated head/taillight assembly, with its own containment casing
2 which is inserted in a suitable housing formed in the body of the reflector of the
associated head/taillight or head/taillight assembly 101, 102, 103 and 104, in a manner
such that its external surface, which faces the environment external to the vehicle
100, is substantially coplanar with the surface of the reflector itself.
[0032] Analogously, the antenna 1 can be substantially integrated into the structure of
the associated side bumper 109, with its own containment casing 2 which is inserted
in a suitable housing formed in the body of the bumper, for example in a manner such
that its external surface, which faces the environment external to the vehicle 100,
is substantially coplanar with the external surface of the side bumper itself.
[0033] In the vehicle 100 according to the invention, the four antennas 1 are connected,
for the purposes and functionalities that will be described in detail below, to a
first control unit 210 that is installed on the vehicle in a remote position distant
from the antennas 1, and is connected to the antennas 1 by means of corresponding
connection cables 211 which may be coaxial or digital type cables depending on the
applications.
[0034] As illustrated in Figure 1 and Figure 9 (in the latter Figure, for only one antenna
1 for simplicity of description) each antenna 1 comprises, arranged inside the casing
2:
- a multilayer structure 5;
- an RF (Radio Frequency) front-end module 3 which comprises a circuitry for managing
the signal transmitted or received by the radiating element 14 and, where present,
the beamsteering/beamforming functionalities, which may be implemented with the analogue,
or digital, or hybrid digital/analogue method; and
- a control interface 4 for connecting the antenna 1 to a corresponding connection cable
211.
[0035] For simplicity of illustration, in the example schematically illustrated in Figure
1, the RF front-end module 3 has been represented as a separate module that is connected
to the multilayer structure 5. Clearly, depending on the applications, the RF front-end
module 3 could be connected to the multilayer structure in this configuration, or
it could be integrated therewith, in the form of further additional layers and/or
by using some of the layers of the multilayer structure 5 described below, such as
for example one or more of the layers 40, 60, 70 and 80.
[0036] In more detailed terms, the multilayer structure 5 comprises a plurality of layers
stacked vertically along the reference direction indicated in Figure 1 by the reference
axis X, the said multilayer structure including at least:
- an upper outer layer 10;
- a first inner layer 20 arranged below the upper outer layer 10;
- a second inner layer 30 arranged below and adjacent to the first inner layer 20; and
- a further layer 40 arranged below and adjacent to the second inner layer 30.
[0037] In particular, in the possible embodiment illustrated in Figures 1 and 2, the upper
outer layer 10 comprises at least a first dielectric sublayer 12, for example made
from ROGERS RO4350B material, and a plurality of first radiating elements 14 suitable
for being fed with and radiating the signals to be transmitted.
[0038] The first radiating elements 14 are made of electrically conductive material, for
example copper, and are arranged spaced apart from each other on the first dielectric
sublayer 12 substantially aligned in sequence along a reference horizontal axis Y
that is perpendicular to the axis X.
[0039] The first radiating elements 14 are preferably substantially identical to each other
and each have a radiating area or surface "A1" measured in a plane transverse to the
axis X, that is to say in the plane of the layer itself. For simplicity of illustration,
this radiating area is clearly indicated in Figure 2 with oblique lines only for one
radiating element 14.
[0040] In the illustrated exemplary embodiment, the first radiating elements 14 are of the
type more precisely referred to as "patches", according to the nationally and internationally
used term, with each having a substantially regular geometrical configuration, for
example square or rectangular or circular.
[0041] In the embodiment illustrated in Figure 1, the upper outer layer 10 has a second
sublayer 18, also referred to hereinafter as the first bonding sublayer 18, for example
made from ROGERS RO4450 material, which is capable of enabling bonding of the upper
outer layer 10 in its entirety with the layer of the plurality of layers immediately
there-below. This first bonding sublayer 18 has a first thickness S1.
[0042] According to one possible embodiment illustrated in Figure 1, and for the purposes
which will be described in more detail below, the multilayer structure of the antenna
1 usefully comprises another inner layer 15, illustrated in Figure 3, which is bonded
to the first bonding sublayer 18, and is therefore interposed between the upper outer
layer 10 and the first inner layer 20.
[0043] Alternatively, in one possible embodiment, the first inner layer 20 may be arranged
immediately below and directly bonded in its upper part to the first bonding sublayer
18; in this case the further layer 15 is not used.
[0044] As illustrated in Figures 1 and 4, the first inner layer 20 comprises at least an
own first sublayer of conductive material 22, constituted for example of a copper
foil, which is arranged on an own second sublayer of dielectric material 26. This
second sublayer of dielectric material 26 may be prepared in a manner such as to have
adhesive properties and enable bonding with the layer of the plurality of layers immediately
there-below, that is to say in the illustrated exemplary embodiment with the second
inner layer 30, or it may be combined with some adhesive material added so as to enable
it to adhere to the subsequent layer.
[0045] Usefully, the first inner layer 20 comprises a plurality of through slots 24, having
for example a U or C shaped form, which pass through the first sublayer of conductive
material 22 and the second sublayer of dielectric material 26 and are suitable for
conveying, towards at least the plurality of first radiating elements 14, the feeding
signals to be radiated originating from the lower layers of the antenna 1 which will
be described below.
[0046] In particular, in the antenna 1 according to the invention for each first radiating
element 14 there is provided at least one corresponding slot 24 operatively associated
thereto; with reference to the substantially vertical direction indicated in Figure
1 by the axis X, each through slot 24 is provided on the first inner layer 20 in an
underlying position corresponding to the position of the associated first radiating
element 14 on the upper outer layer 10.
[0047] Preferably, with reference to the vertical direction represented by the axis X, each
slot 24 extends over the upper horizontal surface of the first inner layer 20 in a
manner such that at least one end portion thereof is outside a virtual area obtained
by projecting vertically (along the direction of the axis X) onto the first inner
layer 20 itself the radiating surface "A1" of the associated first radiating element
14 or alternatively by projecting, again vertically, each slot 24 onto the first inner
layer 20.
[0048] In one possible embodiment, as illustrated in the example of Figure 4, for each first
radiating element 14 there is provided an associated pair of through slots 24, the
two through slots 24 of each pair being formed on the first inner layer 20 in an underlying
position corresponding to the position on the upper outer layer 10 of the associated
first radiating element 14.
[0049] In the illustrated exemplary embodiment, the two slots of each pair of through slots
24, having for example a C or U shaped form, are arranged substantially perpendicular
to each other.
[0050] Also in this case, with reference to the vertical direction represented by the axis
X, each slot 24 extends over the upper horizontal surface of the first inner layer
20 in a manner such that at least one end portion thereof extends outside a virtual
area obtained by projecting vertically onto the first inner layer 20 itself the radiating
surface "A1" of the associated first radiating element 14 (or alternatively by projecting,
again vertically, each slot 24 onto the first inner layer 20).
[0051] Furthermore, at least on the first inner layer 20 a plurality of metallised holes
29 passing through the sublayers 22 and 26 is defined.
[0052] As illustrated in Figures 1 and 5, the second inner layer 30, which is attached above
the sublayer 26, comprises at least an own first dielectric sublayer 32 (also referred
to as third dielectric sublayer 32 to better distinguish it from the dielectric layers
described previously) on which there is arranged a plurality of conductive lines 34,
constituted for example of copper strips, that are suitable for conducting the feeding
signals to be radiated at least towards the plurality of first radiating elements
14.
[0053] In particular, at least one corresponding conductive line 34 is associated with each
radiating element.
[0054] In one possible embodiment, the third dielectric sublayer 32 acts as a bonding layer
and therefore has adhesive properties or includes adhesive material in order to enable
bonding with the layer of the plurality of layers immediately below the inner layer
30, that is to say in the exemplary embodiment illustrated with the further layer
40.
[0055] In particular, the third dielectric sublayer 32, which may be made of or comprise
for example ROGER RO4450 material, has an overall thickness S2 equal to or greater
than the thickness S1 of the first bonding layer 18; in this manner, an improvement
in the adapting or "matching" of the signals is advantageously obtained.
[0056] According to the embodiment illustrated in Figure 5, the plurality of conductive
lines 34 comprises for each first radiating element 14 a corresponding pair of conductive
lines 34 associated therewith, and having for example shapes that differ from each
other.
[0057] More in detail, according to this embodiment, each pair of conductive lines 34 comprises
a first conductive line 34a, formed for example by a copper strip having a substantially
rectilinear development, that is capable of transmitting to the corresponding first
radiating element 14 the feeding signals to be radiated in a first direction of polarisation,
and a second conductive line 34b, for example formed by an L-shaped copper strip,
that is capable of transmitting to said corresponding first radiating element 14,
the feeding signals to be radiated in a second direction of polarisation which is
different from the first direction. These directions may coincide for example with
the direction along the reference axis Z and the direction along the reference axis
Y, illustrated in Figure 5.
[0058] Furthermore, also the third inner layer 30 comprises metallised holes 29 that pass
through its sublayers 34 and 32 and are vertically aligned each with a corresponding
metallised through hole 29 formed on the first inner layer 20.
[0059] Conveniently, each conductive line 34 extends over the plane of the sublayer 32 with
the metallised holes 29 being arranged along both the edges of an associated conductive
line 34 and replicating the path of the line itself.
[0060] Furthermore, in one possible embodiment illustrated in Figure 5, the conductive lines
34a and 34b of adjacent pairs of lines 34 are arranged in a mutually inverted sequence
relative to each other. Furthermore, each line may be flipped to mirror-image or by
180° in the plane of the layer 30 itself, relative to the analogous preceding line.
[0061] More in detail, with reference to a direction of displacement along the axis Y, starting
from the outer transverse edge 31 in a position corresponding to the positioning on
the upper outer layer 10 of the first radiating element 14 arranged closest to the
left edge 11, on the inner layer 30 there is arranged: firstly, the first strip 34a
that is capable of transmitting to the associated first radiating element 14 the feeding
signals to be radiated in the first direction of polarisation; and then successively,
the second conductive line 34b that is capable of transmitting to the same first radiating
element 14 the feeding signals to be radiated in the second direction of polarisation.
Continuing along the direction Y, coincident with the position of the subsequent first
radiating element 14 on the upper outer layer 10, on the layer 30, there is arranged
the second pair of conductive lines 34a and 34b, with the sequence being inverted
and each line 34a and 34b being flipped by 180° relative to the analogous line of
the preceding pair. In practice, proceeding along the axis Y, there is firstly the
second conductive strip 34b, that is capable of transmitting to this subsequent radiating
element 14 the feeding signals to be radiated in the second direction of polarisation,
which is arranged with the L-shaped form flipped by 180° in the plane of the layer
30 relative to the analogous second line 34b of the preceding pair of lines; then,
there is arranged the first line 34a (again flipped to mirror-image or by 180° relative
to the analogous first line 34a of the preceding pair) that is capable of transmitting
to the same subsequent radiating element 14 the feeding signals to be radiated in
the first direction of polarisation. The inversion of the positioning order between
the first strip 34a and the second strip 34b, with any relevant flipping relative
to the analogous lines of the preceding pair, is regularly repeated at each subsequent
radiating element 14 relative to the preceding one.
[0062] Furthermore, in one possible embodiment, one or more of the conductive lines 34,
preferably all of them, comprise each at least one section of line derived in parallel
along the corresponding conductive line 34, preferably arranged to be coincident with
the transition zone which in the exemplary embodiment happens to be close to the outer
edge of the layer, but which in general could be found within a wider layer, and in
particular to be coincident with a transition of a radiofrequency signal, capable
of shifting the signal itself onto a different layer of the antenna, without introducing
significant losses. This derived section makes it possible to artificially introduce
alterations that serve to further enhance the so-called "matching" of the signal transition
zones.
[0063] This derived section of line may be constituted, for example, by a further portion
of strip, and is illustrated in Figure 5 by the reference numeral 34c only for one
pair of conductive lines 34 for the sake of simplicity of description.
[0064] As illustrated in more detail in Figure 6, the further layer 40, which is arranged
below and is adjacent to the second inner layer 30, comprises at least an own first
sublayer of conductive material 42 (hereinafter also referred to as second conductive
sublayer 42 so as to distinguish it from the preceding sublayer 22), constituted for
example of a copper foil, which is arranged on an own second dielectric sublayer 46
(hereinafter also referred to as fourth dielectric sublayer 46 so as to distinguish
it from the previously described dielectric layers).
[0065] The fourth dielectric sublayer 46 as well may be made directly from a material having
adhesive properties or be combined with added adhesive material.
[0066] In particular, the further layer 40 has defined thereon a plurality of first through
openings 44 passing through its sublayers 42 and 46.
[0067] More in detail, with reference to the substantially vertical direction indicated
in Figure 1 by the axis X, each of said first through openings 44 is formed on the
layer 40, and in particular on the sublayer of conductive material 42, in a position
corresponding to the position of at least one associated through slot 24 of the plurality
of through slots 24 defined on the first sublayer of conductive material 22 of the
first inner layer 20.
[0068] Conveniently, in one possible embodiment, with reference to the operation of the
antenna 1 at the nominal operating frequency, each first through opening 44 delimits
an area of through-passage "B", measured transversely relative to the reference axis
X, which is substantially equal to at least λ
2/4, that is to say at least a quarter of the square of the wavelength A measured in
the dielectric material formed by the entire assembly of the third dielectric sublayer
32 immediately above the sublayer of conductive material 42 and the fourth dielectric
sublayer 46 immediately below the sublayer of conductive material 42.
[0069] For the sake of simplicity in illustration, in Figure 6 the area of through-passage
"B" has been represented with oblique lines only for one opening 44.
[0070] In this manner, the presence of through openings 44 formed in particular on the sublayer
of conductive material 42, which acts as a ground plane, substantially prevents the
presence of reflection effects which would affect the quality of the signals transmitted,
while providing for optimized overall dimensions and low costs as compared to different
solutions aimed at tackling the same problem.
[0071] Furthermore, in the illustrated exemplary embodiment, also the further layer 40 comprises
metallised holes 29 which pass through at least its sublayer 42 and are arranged on
parallel rows that are each aligned with a corresponding metallised through hole 29
formed on the first inner layer 20 and on the second inner layer 30.
[0072] As previously mentioned, in one possible embodiment, the multilayer structure of
the antenna 1 according to the invention usefully includes at least one further inner
layer, denoted in Figures 1 and 2 by the reference numeral 15 which is interposed
between the upper outer layer 10 and the first inner layer 20, and is in particular
bonded to the first bonding layer 18 there-above.
[0073] In the embodiment illustrated, the inner layer 15 comprises at least an own dielectric
sublayer 17, hereinafter also referred to as a further dielectric sublayer 17, which
is also made for example from ROGERS RO4350B material, and a plurality of second radiating
elements 16 arranged spaced apart from each other and suitable for being fed with
and radiating the signals to be transmitted.
[0074] In the embodiment illustrated in Figure 1, the inner layer 15 also comprises a further
bonding sublayer 19, for example made from ROGERS RO4450 material, which is capable
of enabling the bonding of the inner layer 15 to the underlying first inner layer
20.
[0075] The second radiating elements 16 are made of electrically conductive material, for
example copper, and are arranged spaced apart from each other on the further dielectric
sublayer 17, substantially aligned along the reference axis Y.
[0076] In particular, relative to the substantially vertical reference direction indicated
by the axis X, each second radiating element 16 is placed below and substantially
aligned, at a certain distance, with a corresponding first radiating element 14.
[0077] In this case, associated with each second radiating element 16 there is at least
one conductive line 34, in particular at least the same conductive line 34 that is
associated with the corresponding first radiating element 14 positioned there-above.
[0078] In the illustrated embodiment, each radiating element 16 is associated with a pair
of conductive lines 34a and 34b; as a consequence thereof, each pair of conductive
lines 34 is associated both with a corresponding second radiating element 16 as well
as with the first radiating element 14 arranged above said corresponding second radiating
element 16.
[0079] The second radiating elements 16 are preferably substantially identical to each other
and each extend over a radiating area or surface "A2" (for simplicity of illustration
clearly indicated in Figure 1 with oblique lines only for one radiating element 16)
and in the illustrated embodiment they are also of the so-called "patch" type.
[0080] In the illustrated embodiment, each second radiating element 16 has a geometric configuration
that is substantially regular, for example square, rectangular or circular.
[0081] Conveniently, the second radiating elements 16 have each a respective radiation area
A2, the latter also measured on a plane transverse to the axis X, that is at most
equal to or preferably less than the radiation area A1 of each of the first radiating
elements 14.
[0082] In practice, the presence of the further layer 15 provided with the second radiating
elements 16 makes it possible to appropriately widen the range of operating frequencies
of the antenna 1 according to the invention.
[0083] Preferably, with reference to the vertical direction represented by the axis X, also
in this case each slot 24 extends over the upper horizontal surface of the first inner
layer 20 in a manner such that at least one end portion thereof is outside a virtual
area obtained by projecting vertically onto the further inner layer 15 itself the
radiating surface "A2" of the associated second radiating element 16 (or alternatively
by projecting, again vertically, each slot 24 onto the further inner layer 15).
[0084] For illustrative purposes, this end portion of each slot 24 is represented only in
Figure 3 in broken line obtained by virtually projecting the slots 24 onto the layer
15. As previously described, an analogous configuration occurs in respect of at least
one end portion of the slots 24 spilling out of the radiation areas A1 of the first
radiating elements 14, even if this illustration has not been replicated in Figure
2 for simplicity.
[0085] According to further possible embodiments, the multilayer structure of the antenna
1 may include one or more further layers.
[0086] In particular, in the exemplary embodiment of Figure 1, there are for example illustrated
a first additional layer 60 (hereinafter indicated as the third inner layer 60), a
second additional layer 70 (hereinafter indicated as the fourth inner layer 70), and
a third additional layer 80 (hereinafter indicated as the lower outer layer 80).
[0087] However, it has to be understood that, according to the applications, in the antenna
1 according to the invention, it is possible to use only one of such additional layers,
only two, e.g. the first and second additional layers 60 and 70, or the first and
third additional layers 60 and 80, or the second and third additional layers 70 and
80, or all of them as it will be described in the following according to the exemplary
configuration depicted in figure 1.
[0088] The first additional or third inner layer 60 is arranged below and is adjacent to
the further inner layer 40, for example bonded to the fourth dielectric sublayer 46.
[0089] In one possible embodiment, and as illustrated in Figures 1 and 7, the third inner
layer 60 comprises an own first sublayer of conductive material 62 (hereinafter also
referred to as third conductive sublayer 62 so as to distinguish it from the preceding
conductive sublayers 22 and 42) which is made for example from a copper foil in order
to bring the feed voltages to the control chips of the antenna 1 and is arranged on
an own second dielectric sublayer 66 (hereinafter also referred to as fifth dielectric
sublayer 66 so as to distinguish it from the previously described dielectric layers)
made from a material having adhesive properties or combined with some added adhesive
material.
[0090] On the inner layer 60 there is defined a plurality of second through openings 64,
which pass through the third conductive sublayer 62 and the fifth dielectric sublayer
66; these second through openings 64, in terms of number and shape thereof, are preferably
substantially identical to the first through openings 44, with each of them being
substantially aligned with a corresponding first through opening 44 relative to a
substantially vertical reference direction defined by the axis X.
[0091] In one possible embodiment, also on the third inner layer and in particular only
on the third conductive sublayer 62 there is defined a plurality of metallised through
holes, not shown in Figure 7, analogous to the through holes 29 indicated above, which
are also arranged so as to be aligned each with a corresponding metallised through
hole 29 formed on the first inner layer 20 and on the further inner layer 40.
[0092] In this case, the through holes also pass through the dielectric layer 46 and, seen
along the vertical direction defined by the reference axis X, when the structure of
the antenna 1 is assembled, form a plurality of through channels that start from the
first sublayer of conductive material 22 and terminate in the third sublayer of conductive
material 62, as schematically illustrated in dashed line in Figure 1.
[0093] Alternatively, these channels formed by the vertically aligned through holes 29 may
terminate at the second sublayer of conductive material 42.
[0094] In case there is used only this first additional layer 60, it will constitute the
lower outer layer of the antenna 1, i.e. the layer located at the lowest position
of the stack of layers used.
[0095] In the embodiment illustrated in figure 1, the fourth inner sublayer 70 is arranged
below and is adjacent to the third inner layer 60, for example bonded to the fifth
dielectric sublayer 66.
[0096] In one possible embodiment, and as illustrated in Figures 1 and 8, the fourth inner
layer 70 comprises at least an own first sublayer of conducting material 72 (hereinafter
also referred to as fourth conducting sublayer 72 so as to distinguish it from the
preceding conducting sublayers 22, 42 and 62), which is made for example from a copper
foil that acts as a ground plane, and is arranged on an own second dielectric sublayer
76 (hereinafter also referred to as sixth dielectric sublayer 76 so as to distinguish
it from the preceding dielectric sublayers) having adhesive properties.
[0097] On the fourth dielectric sublayer 72 there is defined a plurality of third through
openings 74; these third through openings 74, in terms of number and shape thereof,
are preferably substantially identical to the first through openings 44, with each
of them being substantially aligned with a corresponding first through opening 44
relative to a substantially vertical reference direction defined by the axis X.
[0098] In practice, once the various layers of the antenna have been assembled to each other,
the first through openings 44, are substantially aligned, along the vertical development
of the multilayer structure, with the second through openings 64, and/or with the
third through openings 74.
[0099] In particular, in the embodiment of figure 1, the first through openings 44, the
second through openings 64, and the third through openings 74 are substantially aligned
with each other along the vertical development of the multilayer structure.
[0100] In case there is used only the second additional layer 70, i.e. the first additional
layer 60 is not used, the second additional layer 70 will be arranged below and adjacent
to the further inner layer 40 and it will constitute the lower outer layer of the
antenna 1, i.e. the layer located at the lowest position of the stack of layers used.
The second additional layer 70 will also constitute the lower outer layer of the antenna
1 if both the first and second additional layers 60 and 70 are used.
[0101] According to the embodiment illustrated in figure 1, the third additional layer or
lower outer layer 80 is arranged below the fourth inner layer 70 and comprises one
or more connection tracks, schematically illustrated in Figure 8 by dashed lines 82.
These connection tracks are for example constituted of copper traces arranged coincident
with the face of the dielectric sublayer 76 opposite to that on which the conducting
sublayer 72 is arranged. The connection tracks 82 are capable of being connected with
one or more chips (not illustrated) for control and/or conditioning, for example for
phase shifting or amplification, of the feeding signals to be radiated for at least
the plurality of first radiating elements 14 and, where used, also for the second
radiating elements 16.
[0102] If the first and second additional layers 60 and 70 are not used, the third additional
layer 80 will be arranged below and adjacent to the further inner layer 40, and if
the second additional layer 70 is not used, the third additional layer will be arranged
below and adjacent to the first additional layer 60.
[0103] In any case, the third additional layer 80 is preferably meant to constitute the
lower outer layer of the antenna 1.
[0104] In one possible embodiment, the antenna 1 further comprises at least one first series
of parasitic radiating elements 11 and a second series of parasitic radiating elements
13 arranged on at least the said upper outer layer 10, in particular arranged on the
first dielectric sublayer 14. As illustrated in Figure 2, the parasitic radiating
elements 11 and 13 are arranged so as to be aligned along two rows that are parallel
to each other with the plurality of first radiating elements 14 interposed between
them.
[0105] The series of parasitic radiating elements 11 and 13 serve to ameliorate the conformation
of the irradiation beams of the transmitted signals.
[0106] Furthermore, two further series of parasitic radiating elements may also be associated
with the second radiating elements 16, where used; in this case, in a manner analogous
to that which has been described above, these further parasitic radiating elements
may be arranged on the sublayer of conductive material 17 along two parallel rows
with the row of second radiating elements 16 interposed between them.
[0107] Advantageously, in the vehicle 100 according to the invention, the first control
unit 210 of the system 200 is configured in a manner so as to select, in real time,
at least one millimeter antenna 1 from among the four antennas 1 to which it is connected,
from which the signals picked up at the input to the vehicle 100 are to be received,
or to which signals to be radiated externally outside the vehicle 100 are to be transmitted,
on the basis of one or more parameters indicative of the quality of the signal picked
up at the input or transmitted at the output by each of the four millimeter antennas
1.
[0108] Usefully, the first control unit 210 is configured so as to select one single antenna
1 at a time, or to combine the signal received from multiple antennas 1 by means of
digital or analogue methodologies, such as for example applying techniques including
antenna array or diversity or MIMO ("Multiple Input - Multiple Output), of various
types (amplitude and/or phase mixing of multiple signals performed in analogue or
digital mode via Digital Signal Processing or DSP).
[0109] In one possible embodiment, the selection of an antenna 1 is done by detecting the
signal level (Received Signal Strength Indicator - RSSI) of each antenna 1 and choosing
the antenna which provides the highest signal level (with the highest power).
[0110] In the embodiment illustrated in Figure 9, the first control unit 210 comprises a
signal processor 212, such as for example a modem, connected to a control interface
214 for connecting the first control unit 210 to the various connection cables 211.
[0111] In the event that the connections between the first control unit 210 and the antennas
1 are effected via coaxial cables 211, the control interface 4 of each antenna 1 comprises
for example a frequency converter 4A and a control device 4B.
[0112] The frequency converter 4A, which is connected to the RF front-end module 3 and to
the control device 4B, converts an input data signal at millimeter frequencies received
by at least one of the radiating elements 14, 16 into a data signal at a first intermediate
frequency for example between 1 GHz and 6 GHz (depending on the signal bandwidth)
and converts an output data signal, originating from the signal processor 212 at the
first intermediate frequency or at another frequency belonging to the same band of
frequencies, into a data signal at millimeter frequencies in order to be transmitted
by at least one radiating element 14, 16.
[0113] On the same coaxial cable 211, it is possible to convey, in addition to the input
and output data signals originating from and directed to the frequency converter 4A,
also control signals originating from the signal processor 212 for controlling the
frequency converter 4A and the RF front-end module 3 respectively.
[0114] In its turn, the control interface 214 of the first control unit 210 comprises a
control device 216 which communicates with the control device 4B of each antenna 1,
in order to conduct the control signals over the same coaxial cable 211 over which
are transmitted the input and output data signals converted to the first intermediate
frequency.
[0115] In this embodiment, the control device 216 comprises for example an UP (type) frequency
converter that is capable of converting the control signals to a second intermediate
frequency that is different from the first intermediate frequency, for example comprised
in the interval 0.1GHz and 1GHz.
[0116] The control device 216 of the control unit 210 further comprises one or more transceivers
226 for converting the control signals originating from the signal processor 212 into
the second intermediate frequency.
[0117] In its turn, the control device 4B of the antenna 1 comprises for example a DOWN
frequency converter that is capable of converting the control signals from the second
intermediate frequency to a lower frequency in order to be able to control the frequency
converter 4A and the RF front-end module 3. In particular, the control device 4B of
each antenna 1 interprets the control signals and consequently acts on the associated
frequency converter 4A and RF front-end module 3; to this end, the control device
4B comprises for example a transceiver (not shown in detail in the Figures) that converts
the signals from the second intermediate frequency and a logic device, such as a microcontroller
or an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate
Array (FPGA) (also not shown in detail in the Figures).
[0118] Furthermore, in this embodiment, in order to electrically power the antennas 1 through
the same coaxial cables 211 over which the data and control signals pass, the control
unit 210 and each antenna 1 comprise respective power supply blocks (not illustrated
in detail in the Figures) that communicate with each other through the respective
coaxial connection cable 211.
[0119] The control interface 214 comprises a plurality of DA/AD converter units 217, in
which each DA/AD converter unit 217 is connected to a respective antenna 1 and comprises
for example at least one analogue to digital converter (AD) and one digital to analogue
converter (DA).
[0120] In practice, in reception, the millimeter-wave data signal picked up at the input
by at least one radiating element 14, 16 of an antenna 1, is amplified and routed
over a correct path by the corresponding RF front-end module 3 towards the signal
processor 212. In particular, the millimeter-wave data signal picked up at the input
is sent to the frequency converter 4B which converts it to the first intermediate
frequency in order to feed it onto the associated coaxial cable 211. This cable 211
transports it to one of the A/D converters of the converter unit 217 which digitizes
the signal received and sends it to the signal processor 212.
[0121] In transmission, the signal processor 212 emits the output data signal in a digital
format, and at least one DA converter of the unit of converters 217 converts it from
digital to analogue at a first intermediate frequency.
[0122] The output data signal at the first intermediate frequency is transmitted over at
least one coaxial cable 211 and arrives at a frequency converter 4A of at least one
antenna 1 which converts it to millimeter frequencies. The output data signal at millimeter
frequency is amplified and routed by the respective front-end 3 to at least one radiating
element 14, 16 which transmits it into the air.
[0123] The control signals are generated by the signal processor 212 and are sent to the
control device 216 which converts them to a second intermediate frequency and feeds
them into one or more of the coaxial cables 211. The control signals at the second
intermediate frequency then arrive at least at one control device 4B of an antenna
1 and are converted to a lower frequency suitable for controlling the associated frequency
converter 4A and RF front-end module 3.
[0124] In the event that the connection between the antennas 1 and the first control unit
210 is realized through digital cables 211, for example Ethernet cables, the control
interface 4 of each antenna 1 additionally also includes a DA/AD converter unit 4C
comprising a digital/analogue (DA) converter and an analogue/digital (AD) converter
designed to render the analogue signals suitable for digital transmission and vice
versa.
[0125] In this case, the control device of each antenna 1 is for example capable of inserting
into the flow of the input data signal also a signal for diagnosing its status. The
control device 214 of the control unit 210 is capable of inserting into the flow of
the output data signal also the control signals that serve to drive for each antenna
the frequency converter 4A, the RF front-end module 3, and the DA/AD converter unit.
[0126] The control device 4B of each antenna is capable of separating the output data signal
from the control signals. The control device 214 of the unit 210 is capable of separating
the input data signal from the diagnostics signal.
[0127] For this purpose, the control device 4B of each antenna 1 comprises digital transmission
controllers, serialisers/deserialisers that are capable of encapsulating/decapsulating
and digital signals and a computing unit (for example a microcontroller, ASIC or FPGA)
for the management of the devices of the antennas 1, and the control device 214 of
the control unit 210 comprises for example digital transmission controllers and serialisers/deserialisers
that are capable of encapsulating/decapsulating digital signals.
[0128] In the event of connection of the antennas 1 to the first control unit 210 by means
of digital cables 211, some poles of the digital cable 211 may be dedicated to the
transport of DC power supply, thereby avoiding the need for ad hoc power supply blocks.
[0129] In this embodiment, in reception, an input data signal at millimeter frequency is
picked up by at least one radiating element 14, 16 of an antenna 1 and sent to the
corresponding RF front-end module 3 which amplifies and routes it. The input data
signal is converted by the frequency converter 4A from the millimeter frequency to
an intermediate frequency between for example 0.1 GHz and 6 GHz. Then the input data
signal is digitised by an AD converter of the converter unit 4C.
[0130] The control device 4B encapsulates the input data signal together with the diagnostics
signal in a digital communication protocol, in a manner so as to obtain an encapsulated
signal, and transmits it in digital format over the corresponding digital cable 211.
The signal encapsulated in digital format then arrives at the control device 216 of
the control unit 210 which decapsulates it in a manner so as to obtain the input data
signal which is sent to the signal processor 212.
[0131] In transmission, the signal processor 212 emits the output data signal in a digital
format. The control device 216 encapsulates the output data signal with the control
signals in a manner so as to obtain an encapsulated signal which is transmitted over
the digital cables 211. The encapsulated signal is received by the control device
4B of at least one antenna 1 and is decapsulated, in a manner so as to obtain the
output data signal in digital format. The output data signal in digital format is
sent to a DA converter of the converter unit 4C which converts it into analogue. The
analogue output data signal is converted to a millimeter frequency by the frequency
converter 4A. The output data signal at millimeter frequencies is amplified and routed
by the corresponding RF front-end module 3 towards at least one of the radiating elements
14, 16 of the antenna 1 which transmits it into the air.
[0132] The control signals are generated by the signal processor 212 in digital format and
are sent to the control device 216 of the central control unit which encapsulates
them together with the output data signal so as to obtain the encapsulated signal
which is transmitted over one or more digital cables 211. The encapsulated signal
(comprising the output data signal and the control signals) is received by the control
device 4B of at least one antenna 1 which decapsulates the signal so as to obtain
the digital control signals for controlling respectively the respective frequency
converter 4A, the RF front-end module 3 and the DA/AD converter unit 4C.
[0133] Depending on the applications, the antennas 1 can receive/transmit signals by means
of their respective digital cables 211 that are connected to respective dedicated
data buses, or it is possible to use a single shared data bus. In this case, the various
signals that travel in the shared data bus have one address (shared band) and the
identification of the correct sender/receiver takes place by means of the transmission
protocol headers inserted by the respective control devices that encapsulate the signals
to be sent over the shared data bus.
[0134] Conveniently, as schematically illustrated in Figures 1 and 9, the data transceiver
system 200 installed on board the vehicle 100 additionally comprises also a second
set of antennas 230 for transceiving of data in a frequency band lower than the operating
band of the first set of millimeter-wave antennas 1.
[0135] Further, the data transceiver system 200 preferably comprises a second control unit
250 which is operatively associated with and is configured to control the operation
of the second set of antennas 230.
[0136] According to a further embodiment, the data transceiver system 200 further comprises
at least one further antenna 240 for transceiving of data in an intermediate frequency
band between the operating frequency bands of said first and second sets of antennas
1, 230, and the second control unit 250 is also operatively associated with and is
configured to control the operation of the at least one further antenna 240.
[0137] The second control unit 250 is connected to the antennas 230 and/or 240, for example
by means of respective cables 231.
[0138] In particular, as illustrated in Figure 10, the second set of antennas 230 also comprises
at least four antennas 230 which are each installed in a corresponding quadrant of
said four quadrants A, B, C, D, and of which, a first and a second antennas 230 are
installed at the front bumper 106 of the vehicle, for example in proximity to the
respective headlights 101 and 102, and a third and a fourth antennas 230 are installed
at the rear bumper 107, for example in proximity to the respective taillights 103
and 104.
[0139] The four antennas 230 operate at a frequency lower than or equal to 5GHz.
[0140] In its turn, said at least one further antenna 240 may be installed on the roof 108
of the vehicle 100, for example within a cupole or shark fin antenna or it may also
be installed internally inside the vehicle, for example in proximity to the internal
rear-view mirror, or it is possible to use two antennas 240 contemporaneously.
[0141] The or each antenna 240 operates at a frequency in the region of 5.9 GHz, and is
dedicated to the transceiving of Vehicle-to-Everything (V2X) data.
[0142] The antennas 230 and the or each further antenna 240 may be of a type that is commercially
available in the market and for this reason they are not described in detail herein.
[0143] In practice it has been found that the vehicle 100 according to the invention allows
achieving the intended object since the data transceiver system 200 installed on board
represents a good compromise between the number of antennas installed, in particular
of the millimeter-wave type, and effectiveness of the data transmission/reception
coverage around the vehicle 100, with optimized occupation of space and encumbrances.
Furthermore, the structure of the antenna 1 described previously makes it possible
to obtain a solution that combines transmission/reception efficiency with reduced
overall dimensions and production costs. Clearly, where possible or required, it is
possible to add to the optimized configuration described above, one or more further
antennas. For example, if the four millimeter-wave antennas 1 were all installed to
be coincident with the respective four head/taillights or head/taillight assemblies,
it is possible to add one or more antennas 1 installed in the corresponding side bumpers
109, or vice versa, if the four antennas 1 were installed in the respective side bumpers
109, it is possible to add one or more antenna(s) 1 installed in the corresponding
head/taillights or head/taillight assemblies.
[0144] Naturally, the principle of the invention remaining the same, the embodiments and
the particular details of implementation may be widely varied as compared to what
has been described and illustrated purely by way of preferred but non-limiting examples,
without thereby departing from the scope of protection of the present invention as
defined in particular by the attached claims. The shape-form and/or positioning of
the described components or of parts thereof may be appropriately modified provided
that the same is done in a manner compatible with the scope and purpose, and the functionalities
for which the said components have been conceived within the scope of the present
invention.