TECHNICAL FIELD
[0001] The present invention relates to a balise, which is a type of electronic transponder
located between the rails of a railway track typically as a part of an automatic train
protection system. In particular, the invention relates to a balise in the European
Rail Traffic Management System, ERTMS, a so-called Eurobalise. This balise forms an
integral part of the European Train Control System and is specified with respect to
function and design in a European standard called "FFFIS for Eurobalise". A Eurobalise
should comply with the standardization document "SUBSET-036: Specification for Eurobalises".
BACKGROUND AND RELATED ART
[0002] Balises are distributed along railway tracks to send information from the track side
to passing trains enabling safe control of the traffic on the railway tracks through
use of this information by automatic supervising systems on board the trains (railway
vehicles) moving on the railway tracks. Such an automatic supervising system is defined
as an ATP (Automatic Train Protection) system, and it may for instance operate according
to the European standard ERTMS. The link between the balise and an ATP antenna on
the train is based on magnetic coupling, which means that the balise and the ATP antenna
constitute an air transformer whenever the antenna is located above or in a vicinity
of the balise. This link is bi-directional, and the down link from the transmitter
on the railway vehicle transmits power to the balise by magnetic induction of the
receiver loop antenna of the balise, whereas the uplink transmits data to the ATP
system on board the railway vehicle by the use of the transmitter loop antenna of
the balise through the balise transmitter, which is powered by the electric energy
received by the receiver loop.
[0003] The FFFIS for Eurobalise specifies the strength and character of the electromagnetic
fields generated by the Eurobalise and onboard antennas in the train by first defining
two reference loops of predetermined size. Accordingly, the Eurobalise is required
to have an active reference area of 358 mm x 488 mm for a standard size Eurobalise
and an active reference area of 200 mm x 390 mm for a reduced size Eurobalise. The
standard states that the fields generated by the Eurobalise and onboard antenna shall
conform to the fields generated by either one of the reference loops. This implies
that the physical size of the Eurobalise must be largely the same as the reference
loops defined by the standard. In a known Eurobalise, a receiver loop antenna and
a transmitter loop antenna, respectively, were arranged essentially coaxially on the
bottom and top, respectively, of a printed circuit board. The respective loops have
been arranged essentially overlapping in order for both loop antennas to fulfil the
size requirements.
[0004] It is in the nature of the transmission link that the two balise loop antennas should
be close to each other since they are both interacting with the same antenna function
on the train. However, the closer to each other they are positioned, the more capacitive
and inductive coupling is created between them. This has the effect of re-tuning the
transmitter circuitry and receiver circuitry away from the intended resonant frequencies
and the links become inefficient. Consequently, Eurobalises have used thicker than
standard circuit boards. To alleviate the problem of coupling and re-tuning, the above-mentioned
known Eurobalise used a circuit board of about 3.2 mm thickness, that is, about twice
that of today's standard-thickness circuit boards. A large loop separation is achieved
in the known design, which means less coupling between the receiver loop antenna and
the transmitter loop antenna. However, this thickness makes the circuit board heavy
and expensive.
[0005] A balise of the type defined in the preamble of appended claim 1 is known through
EP 3 406 502 A1. The two balise loop antennas, receiver loop antenna and transmitter loop antenna,
should be close to each other since they are both interacting with the same antenna
func¬tion on a train. However, the closer to each other they are positioned, the more
capacitive and inductive coupling is created between them. This has the effect of
re-tuning the transmitter circuitry and receiver circuitry from the intended resonant
frequencies and the links become inefficient.
[0006] Thus, in spite of the requirement stated in claim 1 that "an input flux to the receiver
loop antenna is conform with a predetermined input flux in a balise active reference
area", it would be advantageous to be able to deviate from a geometry match of the
two balise loop antennas as much as to avoid considerable said re-tuning of the transmitter
circuitry and receiver circuitry. For for instance an operating frequency of 27 MHz
as for a Euro¬balise the standard states that ± 1.5 dB is allowed for deviations,
but since the balise active reference area is that large for this frequency, the current
distribution in the receiver loop will not be the same (constant) in the entire loop
of known such balises, so that a considerable part of ± 1.5 dB for deviations allowed
is lost (has been used for the effect of this varying current) and may not be used
for geometry deviations desired.
SUMMARY OF THE INVENTION
[0007] The object of the present invention is to provide a balise being improved with respect
to known balises with regard to addressing the above problems.
[0008] This object is obtained by providing a balise having the features listed in new appended
patent claim 1.
[0009] By providing the receiver loop antenna with two, three, four or more segments separated
by respective gaps and bridging each gap by a capacitance a constant current (a uniform
current distribution) may be achieved in the whole receiver loop meeting the requirement
of conformity with the reference field. This means that it will be possible to make
a geometric deviation from a reference area referred to by a standard, such as SUBSET-036,
since a major part of said ± 1.5 dB may be used for the geometry deviation reducing
capacitive and inductive coupling between the receiver loop antenna and the transmitter
loop antenna of the balise.
[0010] In general the present invention provides a balise in which a receiver loop antenna
and a transmitter loop antenna performances conform with respect to a balise active
reference area of a predetermined nominal size. Further, the balise should allow for
its integration in an ATP system and thus comply with requirements typically defined
in a related standardization document, such as the standard Eurobalise Transmission
System, SUBSET-036, Issue 3.1.0.
[0011] The balise of the present invention is to be arranged stationary between rails of
a railway track to wirelessly transmit data to at least one vehicle antenna of a railway
vehicle on the railway track, wherein the balise comprises: an essentially planar
dielectric circuit substrate having a first side to be facing upwards and a second
side to be facing downwards when the balise is arranged stationary between the two
rails, wherein the circuit substrate has an essentially even substrate thickness;
an essentially rectangular receiver loop antenna formed on said circuit substrate
and having a receiver loop central trace along which is defined a receiver loop physical
length, wherein an input flux to the receiver loop antenna is conform with a predetermined
input flux in a balise active reference area, and wherein the receiver loop antenna
is configured to receive operational energy wirelessly from a vehicle transmitter
in the railway vehicle when in a vicinity of the balise; receiver circuitry connected
by a receiver feed connection to said receiver loop antenna and configured to receive
the operational energy from the receiver loop antenna; an essentially rectangular
transmitter loop antenna formed on said circuit substrate and having a transmitter
loop central trace along which is defined a transmitter loop physical length, wherein
an output field from the transmitter loop antenna is conform with a field from a predetermined
current encircling said balise active reference area and wherein the transmitter loop
antenna is configured to transmit data wirelessly to a vehicle receiver in the railway
vehicle when in a vicinity of the balise; transmitter circuitry connected by a transmitter
feed connection to the transmitter loop antenna and configured to feed to the transmitter
loop antenna a transmit signal including said data; the receiver loop central trace
and the transmitter loop central trace having a mean separation of at least two times
the substrate thickness.
[0012] Loop separation thus achieved allows for an improved material-efficiency and weight
reduction by use of a relatively thin circuit substrate (circuit board) material.
2.5 mm (0.1 inch) or, preferably, 1.6 mm (1/16 inch) would be sufficient. Recent simulations
have shown, contrary to what one would expect, that arranging the receiver loop antenna
inside the transmitter loop antenna in a co-planar fashion will have a tolerably sized
influence on the conformity of the antenna performance of the balise, such that it
still meets the standardization requirements. Specifically, the simulations indicated
that the field strength conformity requirement according to the Eurobalise specifications
was attainable with separate receiver and transmitter loops in the same plane on one
side of the circuit substrate. It should be noted that, in case of a co-planar layout,
the physical dimensions, such as along a central trace, of at least one of the receiver
loop and the transmitter loop will have to deviate clearly from the Eurobalise active
reference area sizes stated in the standardization document.
[0013] The concept of a central trace, an imagined path essentially in the middle of an
antenna loop, for the purpose of definition in this disclosure, is a reasonable approximation
of the path of currents in a loop antenna, although the real transverse distribution
of the currents may deviate somewhat from the middle, typically towards an inner edge
of the loop.
[0014] Due to uneven current distribution phenomena in the receiver loop antenna, particular
care is necessary in order to attain conformity of a balise when the receiver loop
physical length is essentially a tenth or more of a wavelength, as defined in free
space propagation, at operating frequencies of the receiver loop antenna. This is
the case for a Eurobalise of standard size or reduced size. A tenth or more of a wavelength
should be understood as defining a starting point, with a +/- 10% precision, of a
range relating to every operating frequency in question (in a very narrow band at
about 27 MHz for a Eurobalise).
[0015] An advantageous way of overcoming the adverse current distribution phenomena is,
according to the invention, to provide the receiver loop antenna with two, three,
four or more loop segments separated by respective gaps away from the receiver feed
connection, i.e. in addition to a gap that is necessary at the feed connection of
a loop antenna. Each of the at least one gap being bridged by a respective capacitance
so as to render an even current distribution in the receiver loop antenna. At least
in the case of a Eurobalise, the capacitance may be a discrete capacitor component
soldered to adjacent ends of loop segments formed as printed (etched) conductor patterns
on a circuit board. This arrangement of segments and gaps will become particularly
efficient in case the at least one gap is located essentially on a symmetry line of
the receiver loop antenna and/or essentially equidistantly along the receiver loop
antenna.
[0016] Several different arrangements of the receiver loop antenna and the transmitter loop
antenna, respectively, may be realized on a printed circuit substrate of the balise,
each having a set of advantages and, possibly, trade-offs. The receiver loop antenna
and the transmitter loop antenna may both be formed one inside the other on the circuit
substrate. This means that an inner edge of the one loop is wide enough to encircle
an outer edge of the other loop, even if the loops are on opposite sides of the circuit
substrate. It has been found to be advantageous to form the receiver loop antenna
inside the transmitter loop antenna.
[0017] For good performance, at least one of the receiver loop antenna and the transmitter
loop antenna can be provided, preferably overlapping itself, on both sides of the
circuit substrate. An alternative would be to provide the receiver loop antenna on
only one of the sides of the circuit substrate and if so, preferably on the second
side as this tends to give performance gains. Particularly in the latter arrangement,
the transmitter loop antenna is advantageously provided on only one of the sides of
the circuit substrate, preferably on the first side. The transmitter loop antenna
and the receiver loop antenna being only provided on opposite sides of the circuit
substrate may give a particularly advantageous geometry, wherein the thickness of
the dielectric substrate and loop separation in the plane of the dielectric substrate
may both contribute to a relatively large total loop separation. To attain the good
properties, the substrate thickness is less than or equal to one tenth of an inch.
[0018] For the balise disclosed herein a predetermined loop size range may be defined as
a difference between the receiver loop physical length and the transmitter loop physical
length being at least 20 mm, preferably 40 mm.
[0019] As indicated herein, the balise active reference area being a rectangle of either
358 mm by 488 mm, or 200 mm by 390 mm, essentially in concentric and co-planar relation
to the receiver loop antenna and the transmitter loop antenna. Essentially in concentric
and co-planar relation should be understood as typically including an approximation
for cases wherein the receiver loop antenna and the transmitter loop antenna are not
located on the same side only of the circuit substrate. A condition of conformity
for the receiver loop antenna and the transmitter loop antenna, respectively, is +/-
1.5 dB as regards the balise active reference areas.
[0020] The balise of this disclosure is typically a balise with its receiver loop antenna
and its transmitter loop antenna being configured to be in accordance with Eurobalise
Transmission System, SUBSET-036, Issue 3.1.0, although other systematic approaches
are conceivable.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021]
Fig. 1 shows how balises may conventionally be arranged on sleepers of a railway track.
Fig. 2 shows a functional block diagram of a balise according to the present invention.
Fig. 3 shows in a bottom-view a simplified circuit layout of a balise according to
an embodiment of the present invention.
Fig. 4 shows in a top-view a simplified circuit layout of a balise according to an
embodiment of the present invention.
Figs. 5a-5h show in a sectional view alternative printed circuits layout patterns
of the loop antennas according to the invention.
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0022] The drawings are focused on the circuitry of a balise, which is conventionally provided
with a weather-proof housing (not shown) having fastening means for stationary arrangement
on a railway. The drawings are not drawn to scale.
[0023] Fig. 1 shows a balise 1, in this case a Eurobalise, arranged in a stationary location
between rails 2a of a railway track. The balise is typically attached to sleepers
2b of the railway track and may form groups of balises 1. A function of the balise
1 is to wirelessly transmit data to at least one conventional vehicle antenna (not
shown) of a railway vehicle (not shown) travelling on the railway track.
[0024] Fig 2 shows in a simplified manner a functional block diagram of a balise 1 of a
type to which the present invention relates. The balise 1 has a conducting receiver
loop antenna 3 configured to receive electric power by magnetic induction from a vehicle
transmitter antenna (not shown) the vehicle when passing the balise 1. The magnetic
field generated by the transmitter antenna causes a current to flow in the receiver
loop antenna 3. The current is rectified in a receiver 4 and the associated energy
is stored in an energy storage 5. The energy is used to power consumer circuits of
the balise, for instance, a resonant circuit 6 in a transmitter 7 of the balise. The
balise further comprises a conducting transmitter loop antenna 8 configured to be
fed by the resonant circuit 6 to transmit data from a controller 9 to the railway
vehicle via its vehicle antenna, as the vehicle passes the balise. The controller
9 (not part of the present invention) has a serial link input 10 and an input from
a default telegram unit 11 provided with a programming interface 12.
[0025] Fig. 3 and 4 show an essentially planar dielectric circuit substrate 13, also referred
to as a circuit board, of conventional type. It has a first side 14 to be facing upwards
and a second side 15 to be facing downwards when the balise 1 is arranged in its stationary
position between the two rails 2b. The circuit substrate 13 has an essentially even
substrate thickness of about 1.6 or 2.5 mm, and is typically too thin to provide enough
separation of loop antennas overlapping each other on opposite sides of the substrate,
in order to meet the stringent requirements for standardized balises such as the Eurobalise.
Since balises form part of a railway safety system, the designing thereof tends to
be conservative. However, as indicated, a more recent design thereof utilized overlapping
conductive patterns on opposite sides of an extra thick circuit board to provide appropriately
separated receiver and transmitter loops, one on each circuit board side and having
the same predetermined size.
[0026] Fig. 3 and 4 further show essentially rectangular receiver loop antenna 16 formed
on said circuit substrate 13 and having a receiver loop central trace along which
is defined a receiver loop physical length, wherein an input flux to the receiver
loop antenna is conform with a predetermined input flux in a balise active reference
area, and wherein the receiver loop antenna 16 is configured receive operational energy
wirelessly from a vehicle transmitter in the railway vehicle when in a vicinity of
the balise, and receiver circuitry 4 connected by a receiver feed connection 17 to
said receiver loop antenna 16 and configured to receive the operational energy from
the receiver loop antenna 16. There is an essentially rectangular transmitter loop
antenna 18 formed on said circuit substrate 13 and having a transmitter loop central
trace along which is defined a transmitter loop physical length, wherein an output
field from the transmitter loop antenna 18 is conform with a field from a predetermined
current encircling said balise active reference area and wherein the transmitter loop
antenna 18 is configured to transmit data wirelessly to a vehicle receiver in the
railway vehicle when in a vicinity of the balise, transmitter circuitry 7 connected
by a transmitter feed connection 19 to the transmitter loop antenna and configured
to feed to the transmitter loop antenna 18 a transmit signal including said data.
The receiver loop antenna and the transmitter loop antenna are separated to limit
the coupling between them, such that the receiver loop central trace and the transmitter
loop central trace have a mean separation of at least two times the thickness of the
dielectric substrate. In figs. 3 and 4, an inter-loop separation is substantially
larger than double the dielectric substrate thickness, since the receiver loop antenna
is arranged inside, but on an opposing side to, the transmitter loop antenna. As shown,
there is also a separating gap between the two loops in the plane of circuit substrate.
[0027] The Eurobalise of figs. 3 and 4 is standard size or reduced size. This means that
the receiver loop physical length is essentially a tenth or more of a wavelength,
as defined in free space propagation, at the 27.095 MHz operating frequency of the
receiver loop antenna. At such a relation between physical length and wavelength,
the inventive balise provides means for an even current distribution in the form of
capacitors 20 included in the receiver loop antenna 16. This is an advantageous way
of overcoming adverse current distribution phenomena. In the shown example the loop
antenna is provided with four loop segments 21, 22, 23, 24 separated by respective
gaps away from the receiver feed connection 17. Each gap is bridged by a capacitance
25, 26, 27 so as to render an even current distribution in the receiver loop antenna.
For this Eurobalise, the capacitances 25, 26, 27 are discrete capacitor component
soldered to adjacent ends of loop segments 21, 22, 23, 24. This arrangement of segment
and gaps will become particularly efficient in case at least one gap is located essentially
on a symmetry line of the receiver loop antenna and/or essentially equidistantly along
the receiver loop antenna. It should be noted that the feed connections 17 and 19
may or may not overlap.
[0028] Figs. 5a - 5h show several different arrangements of the receiver loop antenna 16
and the transmitter loop antenna 18, respectively, on a printed circuit substrate
13 of the balise. This is illustrated by a section marked A-A in fig. 4. The views
of figs. 5b-5h correspond to that of fig. 5a, but show different designs of the conductive
traces of the loops. It should be noted that there is an aperture in the circuit substrate
inside the loop antennas in fig. 4, which provides for the rather narrow substrate
section of figs 5a - 5h depicting the different loop geometries, each having a set
of advantages and, possibly, trade-offs. The receiver loop antenna and the transmitter
loop antenna may both be formed one inside the other on the circuit substrate. This
means that an inner edge of the one loop is wide enough to encircle an outer edge
of the other loop, even if the loops are on opposite sides of the circuit substrate.
It has been found to be advantageous to form the receiver loop antenna inside the
transmitter loop antenna. Receiver and transmitter loop central traces are indicated
by 28 and 29, respectively.
[0029] If a loop antenna is formed by conductive patterns on both sides of the dielectric
circuit substrate, conductive vias (not shown) through the substrate would typically
be used in various locations to connect the conductive patterns of the loop antenna
on the opposing sides of the substrate. Preferably, this would be the case in figs.
5c, 5d, and 5g.
[0030] For the Eurobalise disclosed in figs. 3 and 4, a predetermined loop size range is
defined as a difference between the receiver loop physical length and the transmitter
loop physical length. In this example, this range is larger than 40 mm and the total
length of the respective loop is about 1692 mm for a Eurobalise of Standard Size or
1180 mm for a Eurobalise of Reduced Size.
[0031] An active reference area of the Eurobalise is a rectangle of either 358 mm by 488
mm, or 200 mm by 390 mm, essentially in concentric and co-planar relation to the receiver
loop antenna and the transmitter loop antenna. Essentially in concentric and co-planar
relation should be understood as typically including an approximation for cases wherein
the receiver loop antenna and the transmitter loop antenna are not located on the
same side only of the circuit substrate. A condition of conformity for the receiver
loop antenna and the transmitter loop antenna, respectively, is +/- 1.5 dB as regards
the balise active reference areas. The Eurobalise of this embodiment has its receiver
loop antenna and its transmitter loop antenna configured to be in accordance with
Eurobalise Transmission System, SUBSET-036, Issue 3.1.0.
[0032] Although described mainly in relation to a Eurobalise, the inventor foresees the
applicability of the inventive balise in accordance with ERTMS/ETCS, Interface 'G'
Specification, SUBSET-100, Issue 2.0.0 of February 24, 2012.
1. A balise to be arranged stationary between rails (2a) of a railway track to wirelessly
transmit data to at least one vehicle antenna of a railway vehicle on the railway
track, said balise comprising:
an essentially planar dielectric circuit substrate (13) having a first side (14) to
be facing upwards and a second side (15) to be facing downwards when the balise is
arranged stationary between the two rails, wherein the circuit substrate has an essentially
even substrate thickness,
an essentially rectangular receiver loop antenna (3, 16) formed on said circuit substrate
(13) and having a receiver loop central trace along which is defined a receiver loop
physical length, wherein an input flux to the receiver loop antenna is conform with
a predetermined input flux in a balise active reference area, and wherein the receiver
loop antenna (3, 16) is configured to receive operational energy wirelessly from a
vehicle transmitter in the railway vehicle when in a vicinity of the balise,
receiver circuitry (4) connected by a receiver feed connection (17) to said receiver
loop antenna (3, 16) and configured to receive the operational energy from the receiver
loop antenna,
an essentially rectangular transmitter loop antenna (8, 18) formed on said circuit
substrate (13) and having a transmitter loop central trace along which is defined
a transmitter loop physical length, wherein an output field from the transmitter loop
antenna (8, 18) is conform with a field from a predetermined current encircling said
balise active reference area and wherein the transmitter loop antenna (8, 18) is configured
to transmit data wirelessly to a vehicle receiver in the railway vehicle when in a
vicinity of the balise,
transmitter circuitry (7) connected by a transmitter feed connection (19) to the transmitter
loop antenna (8, 18) and configured to feed to the transmitter loop antenna a transmit
signal including said data,
characterized in that
the receiver loop central trace and the transmitter loop central trace have a mean
separation of at least two times the dielectric substrate thickness, that the receiver
loop antenna (3, 16) has two, three, four or more loop segments (21-24) separated
by respective gaps in addition to a gap at the receiver feed connection of the receiver
loop antenna, and that
each one of the respective gaps is bridged by a respective capacitance (25-27) so
as to render an even current distribution in the receiver loop antenna (3, 16).
2. The balise according to claim 1, characterized in that
each one of the respective gaps are located equidistantly along the receiver loop
antenna (3, 16).
3. The balise according to claim 1 or 2, characterized in that
the receiver loop physical length is a tenth or more of a wavelength, as defined in
free space propagation, at operating frequencies of the receiver loop antenna (3,
16).
4. The balise according to any preceding claim, characterized in that
the receiver loop antenna (3, 16) and the transmitter loop antenna (8, 18) both are
formed one inside the other on the circuit substrate (13), and that the receiver loop
antenna is formed inside the transmitter loop antenna (8, 18).
5. The balise according to any preceding claim, characterized in that
the receiver loop antenna (3, 16) is formed, preferably overlapping itself, on both
sides of the circuit substrate (13).
6. The balise according to any preceding claim, characterized in that
the transmitter loop antenna (8, 18) is formed, preferably overlapping itself, on
both sides of the circuit substrate (13).
7. The balise according to any of claims 1-4, characterized in that
the receiver loop antenna (3, 16) is provided on only one of the sides of the circuit
substrate (13), preferably on the second side (15).
8. The balise according to any of claims 1-4, characterized in that
the transmitter loop antenna (8, 18) is provided on only one of the sides of the circuit
substrate, preferably on the first side (14).
9. The balise of claims 1-4 and 7 and 8, characterized in that
the transmitter loop antenna (8, 18) and the receiver loop antenna (3, 16) are only
provided on opposite sides of the circuit substrate (13).
10. The balise according to any preceding claim, characterized in that
the substrate thickness is less than or equal to 2.54 mm (0.1 inch).
11. The balise according to any preceding claim, characterized in that
a predetermined loop size range is defined as a difference between the receiver loop
physical length and the transmitter loop physical length being at least 20 mm, preferably
40 mm.
12. The balise according to any preceding claim, characterized in that
the balise active reference area is a rectangle of either 358 mm by 488 mm, or 200
mm by 390 mm, in concentric and co-planar relation to the receiver loop antenna (3,
16) and the transmitter loop antenna (8, 18).
1. Balise, die stationär zwischen Schienen (2a) eines Eisenbahngleises anzuordnen ist,
um Daten drahtlos an mindestens eine Fahrzeugantenne eines Schienenfahrzeugs auf dem
Eisenbahngleis zu übertragen, wobei die Balise Folgendes umfasst:
ein im Wesentlichen planes dielektrisches Schaltungssubstrat (13) mit einer ersten
Seite (14), die nach oben gewandt ist, und einer zweiten Seite (15), die nach unten
gewandt ist, wenn die Balise stationär zwischen den zwei Schienen angeordnet ist,
wobei das Schaltungssubstrat eine im Wesentlichen gleichmäßige Substratdicke aufweist,
eine im Wesentlichen rechteckige Empfängerschleifenantenne (3, 16), die auf dem Schaltungssubstrat
(13) ausgebildet ist und eine zentrale Empfängerschleifenbahn aufweist, entlang welcher
eine physische Empfängerschleifenlänge definiert ist, wobei ein Eingangsfluss zur
Empfängerschleifenantenne einem vorbestimmten Eingangsfluss in einem aktiven Balisenreferenzbereich
entspricht und wobei die Empfängerschleifenantenne (3, 16) dazu ausgestaltet ist,
Betriebsenergie drahtlos von einem Fahrzeugsender in dem Schienenfahrzeug zu empfangen,
wenn sich dieses in der Nähe der Balise befindet,
eine Empfängerschaltungsanordnung (4), die durch eine Empfängerzufuhrverbindung (17)
mit der Empfängerschleifenantenne (3, 16) verbunden und dazu ausgestaltet ist, die
Betriebsenergie von der Empfängerschleifenantenne zu empfangen,
eine im Wesentlichen rechteckige Senderschleifenantenne (8, 18), die auf dem Schaltungssubstrat
(13) ausgebildet ist und eine zentrale Senderschleifenbahn aufweist, entlang welcher
eine physische Senderschleifenlänge definiert ist, wobei ein Ausgangsfeld von der
Senderschleifenantenne (8, 18) einem Feld von einem vorbestimmten Strom, der den aktiven
Balisenreferenzbereich umgibt, entspricht und wobei die Senderschleifenantenne (8,
18) dazu ausgestaltet ist, Daten drahtlos an einen Fahrzeugempfänger in dem Schienenfahrzeug
zu senden, wenn sich dieses in der Nähe der Balise befindet,
eine Senderschaltungsanordnung (7), die durch eine Senderzufuhrverbindung (19) mit
der Senderschleifenantenne (8, 18) verbunden und dazu ausgestaltet ist, der Senderschleifenantenne
ein die Daten umfassendes Sendesignal zuzuführen,
dadurch gekennzeichnet, dass
die zentrale Empfängerschleifenbahn und die zentrale Senderschleifenbahn einen mittleren
Abstand von mindestens dem Zweifachen der Dicke des dielektrischen Substrats aufweisen,
dass die Empfängerschleifenantenne (3, 16) zwei, drei, vier oder mehr Schleifensegmente
(21-24) aufweist, die durch entsprechende Spalte zusätzlich zu einem Spalt an der
Empfängerzufuhrverbindung der Empfängerschleifenantenne beabstandet sind und dass
jeder der entsprechenden Spalte durch eine entsprechende Kapazität (25-27) überbrückt
ist, um eine gleichmäßige Stromverteilung in der Empfängerschleifenantenne (3, 16)
zu erhalten.
2. Balise nach Anspruch 1, dadurch gekennzeichnet, dass
jeder der entsprechenden Spalte mit einem gleichen Abstand entlang der Empfängerschleifenantenne
(3, 16) angeordnet ist.
3. Balise nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass
die physische Empfängerschleifenlänge bei Betriebsfrequenzen der Empfängerschleifenantenne
(3, 16) einem Zehntel oder mehr einer Wellenlänge, wie gemäß Freiraumausbreitung definiert,
entspricht.
4. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
die Empfängerschleifenantenne (3, 16) und die Senderschleifenantenne (8, 18) beide
ineinander auf dem Schaltungssubstrat (13) ausgebildet sind und dass die Empfängerschleifenantenne
innerhalb der Senderschleifenantenne (8, 18) ausgebildet ist.
5. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
die Empfängerschleifenantenne (3, 16), vorzugsweise sich selbst überlappend, auf beiden
Seiten des Schaltungssubstrats (13) ausgebildet ist.
6. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
die Senderschleifenantenne (8, 18), vorzugsweise sich selbst überlappend, auf beiden
Seiten des Schaltungssubstrats (13) ausgebildet ist.
7. Balise nach einem der Ansprüche 1-4, dadurch gekennzeichnet, dass
die Empfängerschleifenantenne (3, 16) auf nur einer der Seiten des Schaltungssubstrats
(13), vorzugsweise auf der zweiten Seite (15), ausgebildet ist.
8. Balise nach einem der Ansprüche 1-4, dadurch gekennzeichnet, dass
die Senderschleifenantenne (8, 18) auf nur einer der Seiten des Schaltungssubstrats,
vorzugsweise auf der ersten Seite (14), ausgebildet ist.
9. Balise nach den Ansprüchen 1-4 und 7 und 8, dadurch gekennzeichnet, dass
die Senderschleifenantenne (8, 18) und die Empfängerschleifenantenne (3, 16) nur auf
gegenüberliegenden Seiten des Schaltungssubstrats (13) bereitgestellt sind.
10. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
die Substratdicke kleiner oder gleich 2,54 mm (0,1 Inch) ist.
11. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
ein vorbestimmter Schleifengrößenbereich als Differenz zwischen der physischen Empfängerschleifenlänge
und der physischen Senderschleifenlänge definiert ist und mindestens 20 mm, vorzugsweise
40 mm, beträgt.
12. Balise nach einem vorangehenden Anspruch, dadurch gekennzeichnet, dass
der aktive Balisenreferenzbereich ein Rechteck von entweder 358 mm mal 488 mm oder
200 mm mal 390 mm in einem konzentrischen und koplanaren Verhältnis zu der Empfängerschleifenantenne
(3, 16) und der Senderschleifenantenne (8, 18) ist.
1. Balise à disposer stationnaire entre des rails (2a) d'une voie ferrée pour émettre
sans fil des données à au moins une antenne de véhicule d'un véhicule ferroviaire
sur la voie ferrée, ladite balise comprenant :
un substrat de circuit diélectrique essentiellement plan (13) ayant un premier côté
(14) devant être tourné vers le haut et un deuxième côté (15) devant être tourné vers
le bas lorsque la balise est disposée stationnaire entre les deux rails, dans laquelle
le substrat de circuit a une épaisseur de substrat essentiellement uniforme,
une antenne cadre de récepteur essentiellement rectangulaire (3, 16) formé sur ledit
substrat de circuit (13) et ayant une piste centrale de cadre de récepteur le long
de laquelle est définie une longueur physique de cadre de récepteur, dans laquelle
un flux d'entrée vers l'antenne cadre de récepteur est conforme à un flux d'entrée
prédéterminé dans une zone de référence active de balise, et dans laquelle l'antenne
cadre de récepteur (3, 16) est configurée pour recevoir de l'énergie opérationnelle
sans fil depuis un émetteur de véhicule dans le véhicule ferroviaire lorsqu'il est
à proximité de la balise,
une circuiterie de récepteur (4) connectée par une connexion d'alimentation de récepteur
(17) à ladite antenne cadre de récepteur (3, 16) et configurée pour recevoir l'énergie
opérationnelle depuis l'antenne cadre de récepteur,
une antenne cadre d'émetteur essentiellement rectangulaire (8, 18) formée sur ledit
substrat de circuit (13) et ayant une piste centrale de cadre d'émetteur le long de
laquelle est définie une longueur physique de cadre d'émetteur, dans laquelle un champ
de sortie depuis l'antenne cadre d'émetteur (8, 18) est conforme à un champ provenant
d'un courant prédéterminé qui encercle ladite zone de référence active de balise et
dans laquelle l'antenne cadre d'émetteur (8, 18) est configurée pour émettre des données
sans fil vers un de récepteur de véhicule dans le véhicule ferroviaire lorsqu'il est
à proximité de la balise,
circuiterie d'émetteur (7) connectée par une connexion d'alimentation d'émetteur (19)
à l'antenne cadre d'émetteur (8, 18) et configurée pour alimenter vers l'antenne cadre
d'émetteur un signal d'émission comportant lesdites données,
caractérisée en ce que
la piste centrale de cadre de récepteur et la piste centrale de cadre d'émetteur ont
une séparation moyenne d'au moins deux fois l'épaisseur de substrat diélectrique,
en ce que l'antenne de cadre de récepteur (3, 16) a deux, trois, quatre segments de cadre (21-24)
ou plus séparés par des écarts respectifs en plus d'un écart au niveau de la connexion
d'alimentation de récepteur de l'antenne de cadre de récepteur, et en ce que
chacun des écarts respectifs est ponté par une capacité (25-27) respective de manière
à rendre une distribution de courant uniforme dans l'antenne cadre de récepteur (3,
16).
2. Balise selon la revendication 1, caractérisée en ce que
chacun des écarts respectifs est situé de manière équidistante le long de l'antenne
cadre de récepteur (3, 16).
3. Balise selon la revendication 1 ou 2, caractérisée en ce que
la longueur physique de cadre de récepteur est un dixième ou plus d'une longueur d'onde,
telle que définie en propagation en espace libre, aux fréquences de fonctionnement
de l'antenne de cadre de récepteur (3, 16).
4. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
l'antenne cadre de récepteur (3, 16) et l'antenne cadre d'émetteur (8, 18) sont toutes
deux formées l'une à l'intérieur de l'autre sur le substrat de circuit (13), et en ce que l'antenne cadre de récepteur est formée à l'intérieur de l'antenne cadre d'émetteur
(8, 18).
5. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
l'antenne cadre de récepteur (3, 16) est formée, de préférence en se chevauchant elle-même,
sur les deux côtés du substrat de circuit (13).
6. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
l'antenne cadre d'émetteur (8, 18) est formée, de préférence en se chevauchant elle-même,
sur les deux côtés du substrat de circuit (13).
7. Balise selon l'une quelconque des revendications 1 à 4, caractérisée en ce que
l'antenne cadre de récepteur (3, 16) est prévue sur un seul des côtés du substrat
de circuit (13), de préférence sur le deuxième côté (15).
8. Balise selon l'une quelconque des revendications 1 à 4, caractérisée en ce que
l'antenne cadre d'émetteur (8, 18) est prévue sur un seul des côtés du substrat de
circuit, de préférence sur le premier côté (14).
9. Balise selon les revendications 1 à 4 et 7 et 8, caractérisée en ce que
l'antenne cadre d'émetteur (8, 18) et l'antenne cadre de récepteur (3, 16) sont uniquement
prévues sur des côtés opposés du substrat de circuit (13).
10. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
l'épaisseur du substrat est inférieure ou égale à 2,54 mm (0,1 pouce).
11. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
une plage de taille de cadre prédéterminée est définie comme une différence entre
la longueur physique de cadre de récepteur et la longueur physique de cadre d'émetteur
qui est d'au moins 20 mm, de préférence 40 mm.
12. Balise selon l'une quelconque des revendications précédentes, caractérisée en ce que
la zone de référence active de balise est un rectangle soit de 358 mm par 488 mm,
soit de 200 mm par 390 mm, en relation concentrique et coplanaire avec l'antenne cadre
de récepteur (3, 16) et l'antenne cadre d'émetteur (8, 18).