ES2644589T3 - Grouping of stacked patch antennas - Google Patents

Description

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DESCRIPTION

Grouping of stacked patch antennas

This invention relates to an antenna that can be used with multiple satellite navigation and global positioning systems, such as both the NAVSTAR GPS and the Galileo GNSS.

There are currently a series of satellite navigation and global positioning systems, such as the United States NAVSTAR Global Positioning System (GPS) mentioned above, which was developed by the US military. in the 70s. Each system is based on the transmission of range signals in particular frequency bands.

Currently, in NAVSTAR GPS, there are over 30 GPS satellites orbiting the Earth. However, at any time there are at least 24 functional GPS satellites orbiting the Earth in 12-hour orbits; four satellites in each of six orbit planes, each transmitting a range signal. A typical GPS receiver requires signals of at least four GPS satellites to determine its position using geometry and triangulation.

NAVSTAR GPS is based on transmission of range signals in frequency bands that include L1 (1,575 MHz), L2 (1,227 MHz), L3 (1,381 MHz) and L5 (1,176 MHz), all of which have a bandwidth of 20 MHz. Other satellite navigation systems use different and wider frequency bands. For example, the new GNSS called Galileo, which is to be deployed by the European Union, operates in frequency bands that are different from those used by NAVSTAR GPS, including E5a (1,166.45 to 1,186.45 MHz) and E5b (1,197.14 to 1,211.14 MHz). Since the two bands E5 (E5a and E5b) are very close to each other, it can be assumed that both bands will combine and have a combined bandwidth of 45 MHz.

There is therefore a need for an antenna, which can receive signals emitted in the multiple frequency bands of either of the two systems, while using existing GPS installations. This requirement is particularly relevant in flight applications where a reconditioning of the legacy installation is necessary to reduce the cost without compromising navigability. In addition, a multi-standard antenna for both NAVSTAR and Galileo GNSS gps effectively dual band, with the upper frequency band from 1,565 to 1,585 MHz (L1) and the lower frequency band from 1,166 to 1,211 MHz (E5 ).

However, there is a problem in that, with antenna systems, the physical size of the antenna is related to the bandwidth of the system and as the bandwidth of the Galileo GNSS is more than double that of the NAVSTAR GPS, it differs the size of the respective antennas.

In addition, the radiation pattern for the GNSS antenna in flight of multiple standards is expected to have advanced features in terms of coverage and more stringent requirements on the purity of its polarization compared to today's single-band GPS antennas.

EP-A-0270209 describes a dual band antenna and US5245745 describes a method of making a thick peffcula patch antenna structure.

Therefore, an object of the present invention is to provide a multi-standard radiator for a GNSS antenna, which can receive range signals transmitted in multiple frequency bands from different GNSS, while still having a global physical size that ensures that the Antenna set can be backward compatible with docking stations / GPS fixings and installations on board a vehicle where it is to be used.

According to the present invention a radiating element plate is provided for use in a passive antenna, the radiating element plate comprising a plurality of multi-layer radiating elements, each of which comprises:

a first patch provided in a first layer to receive signals within a first frequency band; Y

a second patch provided in a second layer to receive signals within a second frequency band,

wherein the plurality of radiating elements are arranged on the radiating element plate so that each radiating element is rotated sequentially at a predetermined angle from its neighboring element, all elements being rotated in the same direction and in the same plane, in where each patch is shorted to ground along one edge of the patch so that multi-band radiation can escape only from a virtual slot provided substantially along the opposite edge of the corresponding patches; characterized in that each patch has serrated teeth provided along a first edge opposite to the shorted edge to ground for broadband and tuning purposes.

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An example of the present invention will now be described with reference to the following figures, in which:

Figure 1 is an exploded view of a multi-standard radiator comprising a plate of radiating elements according to the present invention;

Figure 2 shows a group of radiating elements comprising a plate of radiating elements; Figure 3 shows the patches of the radiating elements;

Figure 4 is a cross-sectional view of Figure 3 taken between two of the patches; Figures 5 (a) to (d) show examples of different feed structures for patches; Figure 6 is a schematic diagram of a polarization formation network;

Tables 7 (a) and 7 (b) show the minimum and maximum gain, respectively, above the horizon;

Figures 8 (a) and 8 (b) show an antenna radiation pattern template and a close-up of the details along the horizon, respectively; Y

Figure 9 is a cross-sectional illustration of a radiating element, showing the relative distances between the short circuit and the supply lines.

Figure 1 is an exploded view of a radiator of multiple standards 1, comprising a plate of radiant elements 2 according to the present invention. The radiating element plate 2 is attached to a polarization formation network circuit board 3 and enclosed within a radome 4, which is sealed against a base plate 5 that has grooves to accommodate components of the formation circuit circuit board. polarization 3. Radome 4 can be made of "PTFE", "Nylon" or a similar material, approximately 2.5 mm thick. The radome (4) is attached, using an epoxy resin bonding film, to the base plate 5, which is ideally aluminum. A gasket 7, preferably of neoprene or plastic, can be provided to ensure a good seal between radome 4 and base plate 5. Alternatively, the radome can be glued directly to the base plate with structural adhesive. An outlet 9 to the radiator of multiple standards 1 is provided on the underside of the base plate 5.

Alternatively, the radome can be a foam filled radome, which is formed around the elements to keep the antenna weight low while ensuring high mechanical stability, while preventing moisture from entering as well as mitigating adverse effects. of differential pressure.

Figure 2 shows a grouping of four passive radiating elements 10, which form a plate of radiating elements 2 according to the present invention. The elements 10 are arranged to form a plate of radiant elements 2 substantially square, where each element 10 is rotated 90 degrees from its neighbor and all the elements 10 are rotated in the same direction. The arrangement shown in Figure 2 provides a right circular polarization although it will be appreciated that a left polarization could also be achieved when the elements are oriented in the other direction.

Each passive radiant element 10 comprises two patches 11, 12 separated by dielectric material 13, which is ideally a plastic material of RF quality. The dielectric material is preferably in the form of a stratified dielectric, based on different properties that are important in terms of dielectric permittivity and which are both determined by the required operating frequency of the corresponding patch plus the limitations imposed on the maximum global space that the maximum patch can occupy more than the minimum bandwidth required for the corresponding operation.

Stratified dielectric material has been found to provide superior performance when compared to dielectric material only, as will be explained in more detail later. However, one expert will recognize that, although stratified dielectric material is preferred, in the case of GPS / Galileo antenna there are many dielectric materials that can allow proper operation in a unique way to meet reduced antenna specifications at a lower cost.

The dielectric material 13 provided in the radiant elements 10 of the present invention is substantially in the form of dielectric plates 13. Alternatively, the space between patches 11, 12 may be filled with air or foam, as mentioned above.

The construction of the antenna therefore offers potential in terms of controlling the volume of the antenna while at the same time allowing the antenna to operate in substantially separate frequency bands. This derives from the fact that a predefined maximum volumetric envelope can be made compatible with various frequency operation by ensuring that the electrical size of the antenna is suitable for the prescribed frequencies using a common location for power and short-circuit position. Such choice also allows the flexibility to introduce the geometric features required for efficient and precise manufacturing and tuning using only commercially available RF materials without resorting to the need for specialized variants or sophisticated production methods.

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The first patch 11, provided for the frequency band (L1), (L2), (L3) or (L5) of NAVSTAR and Galileo GPS, is arranged to be outside each radiating element 10. A second patch 12, physically larger, is provided on an inner layer of each element 10, with a dielectric plate 13 provided on either side of it, and simultaneously covers the frequency bands (both E5A and E5B) of GPS and Galileo The passive radiant elements 10 are constructed using multi-layer printed circuit board (PCB) technology, that is, several substrate layers bonded together to create a thick multi-layer assembly.

The dielectric material 13, provided in the radiant element 10 between the patches 11, 12 and on either side of the internal patch 12, ensures that the proper operation in terms of the antenna's standing voltage (VSWR) ratio is achieved by doing the antenna resonate in the bands of interest. In addition, this ensures that the overall physical size of the antenna 1 is backwards compatible with existing GPS docking stations / installations and on-board facilities such as commercial aircraft, where it is to be used.

For example, many aircraft currently employ only GPS antennas with fixings that fit the particular shape as dictated by the ARINC743A standard. Any deviation from the details outlined in this standard is likely to be unacceptable in terms of the cost of installation and operation of the global airplane structure. The increased height is necessary so that, in addition to bandwidth, the antenna group delay is generally acceptable. It is well known that the Q factor of an antenna is inversely related to the volume it occupies. It is also well known that the response to the Group delay of the antenna and its variation across the band is proportional to the Q of the cavity of the underlying antenna. Therefore the antenna bandwidth response is crucial in maintaining the required group delay performance.

Figure 3 shows the arrangement of the radiating elements 10 on a plate of radiating elements 2 according to the present invention without the dielectric material 13 shown. Both of the external patches 11 and the internal patches 12 of each radiant element 10 are short-circuited by wires 14 that pass through one of their edges, the wires 14 that connect both patches 11, 12 to ground in order to achieve a quarter wave operation and ensure that the overall mechanical size is physically controlled.

The short circuits 14 are placed at the edges of each external patch 11 and internal patch 12. This alignment is very useful when the overall antenna assembly is manufactured because the placement of the short circuit can act as an alignment line when the patches are aligned. 11, 12. The alignment of the short circuit 14 is also useful for tuning the antenna, especially the internal patch 12, to the extent that it allows the radiating edge of the internal patch 12 to be exposed.

In the form of a stratified dielectric, the dielectric plates 13 provide improved flexibility over the dielectric plates 13 in a unique way, which allows the electrical distances of short-circuit power points 14 in two different bands for patches 11, 12 to be equalized, while maintaining the same mechanical distance. The electrical distance between the supply wire and the short circuit 14 has to be the same for both the external patch 11 and the internal patch 12. This can be achieved when the effective dielectric properties of the patches 11, 12 are adequate and tuned to fine way taking into account the different frequencies and bands at which the two patches 11, 12 can operate.

This can also be explained with reference to Figure 9. If one assumes that the external patch 11 needs to be tuned in a band with a center frequency f1 (for example the L1 of GPS or Galileo) and the internal patch 12 in a band of frequency with a central value f2 (for example the L5 of GPS or E5 of Galileo), in order for the desired resonance to be achieved, it is required to tune out of the reactive part of the actuation impedance Z1 or Z2 for the respective patches in the center of the respective frequencies.

Within the preferred configuration this resonance operation is achieved when the feed is loaded by an additional effective reactance X1 and X2 respectively. The part of the antenna that offers this resonance reactance is the one formed between the power point and the short circuit formation. In fact, this section behaves like two stacked short transmission lines of common length ds charged at the other end by the inductances La and Lb representing in a realistic electrical way the metal-plated short-circuit through holes or any other alternative embodiment.

The transmission line equations can be written as follows:

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_. (2sr La / l + Zatan ^ ds))

J (Za ~ 2nLa / I tan (/ ?, ds)) X2 =. (2; rLb f 2 + Zb tan (/ 7, (fa)) ^ Zb ~ 2jt Lb f 2 tan (/ ?, ds))

with

The way of synthesizing the resonance reactances required within the described antenna is through control of the characteristic impedances Za and Zb as well as the propagation constants p1 and p2 of the effective transmission lines offered by the antenna section to the short circuit location. By inspecting the corresponding transmission line equations shown above, we can see that the short-circuit inductances La, Lb can be transformed at resonance impedance X1, X2 at the center of the two different operational bands with an adequate choice of massive electrical permissivities £ a, £ b and a common value ds for the separation of the power point and the short-circuit location for both the upper and the lower patch.

The precise determination for the values of £ a, £ b and ds is the result of mathematical optimization based on a detailed electromagnetic model. The objective of design optimization is the bandwidth required per band as well as the maximum return loss (or VSWR) that can be tolerated at the edges of the band.

The practical approximation of the corresponding plates with the massive dielectric contents £ a, £ b is based on the stratification process where the mass average value is approximately the average of the materials used weighted by the corresponding thickness.

In addition, the mathematical process can also produce a solution for the £ a, £ b and ds under the restriction that the upper and lower patches offer a gap between their edges of a given size suitable for accommodating tuning teeth on the lower patch Accessible from above. A typical value for g is of the order of 5 mm.

Accordingly, dielectric plates 13 can be formed from stratification of ordinary commercial dielectric materials, found in the majority of standard product ranges of material manufacturers, which offer a different but limited range of dielectric constants to synthesize the desired dielectric properties. . This synthesis is achieved using one or more ordinary commercial materials with a suitable thickness, which is dictated by the massive dielectric constant to be synthesized, as outlined above.

The cutting threads are preferably formed using through holes or plated rods. Of course, it will be appreciated that alternative means of short-circuiting patches 11, 12 to ground can also be used and designed specifically for a particular application. For example, veneer the edge of the PCB with a solid metal layer, or use a series of flat metal strips instead of wires. The number of threads 14 and their diameters also need to be precisely controlled. The wires can be thought of as an additional inductive load in series of an otherwise resonant cavity formation. Therefore, an adequate choice of its number and diameter can affect both of the resonant frequencies required for a given size and arrangement of antenna element as well as its resonance bandwidth. In addition other short-circuiting means can be used in terms of metal strips.

The use of plated rods, however, avoids problems that may be encountered with other short-circuit means such as metal pins, which may be uncomfortable as short-circuit enablers. In particular, for thicker patches, it is difficult to achieve the required welding, especially in the internal patch 12 and even then such a process is imperfect for a desired smooth set of the antenna with an adverse effect on tuning and performance. Using plated rods, there is no need to weld to the extent that the formation of the hole holes takes place using standard printed circuit techniques in parallel with the patches within the same manufacturing frame. Therefore, no finishing process is required, as regards the welding of metal pins.

In Figure 3 it can also be seen that each of the patches 11, 12 also has a serrated edge, preferably provided on the opposite side to the side that is shorted. These serrated edges form tuning teeth, which allow fine tuning of the antenna after assembly where, in a controlled manner, some teeth 15 can be physically removed to the point that the frequency operation fits into the required frequency bands. By arranging the tuning teeth 15 along the same side of each of the patches 11, 12, when multiple radiating assembly plates are arranged to form an antenna, tuning is possible by modifying and / or eliminating the teeth 15 without negative effect. in the quality of circular polarization. Preferably, the dielectric plates 13 do not extend over the teeth 15 of the internal patch 12, which allows them to be adjusted to the set of the antennas.

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Typically, 10-20 teeth are regularly distributed over the entire length of the single radiant edges of both of the upper and lower patches. With typical tooth lengths of the order of 5 mm it is possible to fine tune the antenna within a fraction of MHz. The regularity of the distribution of the teeth allows us to easily apply the same tuning modification to all the corresponding patches of the formation of grouping thus maintaining the symmetry that is essential for a good performance of circular polarization. Of course, different numbers of teeth and tooth lengths are possible depending on the required configuration.

Figure 4 is a cross-sectional view of Figure 3, showing each element 10 having a power structure comprising an individual power plug 16 that passes through it. In this example, the power plug 16 originates in the external patch 11, passes through a hole 17 provided in the internal patch 12 and then out through the base of the radiating element plate 2. The power pins 16 connect by therefore each individual element 10 to the circuit board 3.

A series of other feeding structures are possible, as illustrated in Figures 5 (a) - (d). For example, as shown in Figure 5 (a), a feed signal can be fed into the element through a cylinder 18 provided at the bottom of an element 10, with a feed pin 16 running through the cylinder to connect it to the bottom of the element and therefore to the internal patch 12, to the extent that the power plug 16 passes through the hole 17 provided in the internal patch 12 to connect with the external patch 11. In this example, the cylinder Inserted metallic coaxial 18 that loads the feed wire serves to offer an incremental transmission line in series that allows a degree of freedom in terms of a conventional impedance transformation with cascaded lines of different characteristic impedance. It can also be used as a charge of capacitive element of derivation mainly additional from the feeding point.

Alternatively, as shown in Figure 5 (b), one or two discs 19 can be provided in the upper and lower parts, respectively, of the element 10 that passes through the power plug 16, thereby connecting the external patch 11 and the internal patch 12 to the circuit board 3. The feeder 16 loaded with disc 19 mainly allows a distributed load of the line that can resemble a low-pass section of capacitor inductor-LC loaded.

Another option, shown in Figure 5 (c), is to feed a signal through a power plug 16 in the vicinity of one or more tuning posts 20 parasitically driven at the base of an element 10, on the side of the hole 8 that passes through the power plug 16 to enter the element 10. Also referred to as the load of the parasitic terminal 20 of the power point 16, this arrangement, mainly through the capacitive nature, can also be generally provided as a load of series LC capacitor inductor section in parallel with the impedance of the drive point.

Still another option is to provide a groove 21 at the base of an element 10, as shown in Figure 5 (d). The groove 21 is substantially perpendicular to a metal strip 22 provided in the circuit board 3 on which the element is mounted. In this example, when a feed signal is fed to the metal strip 22 on the circuit board 3, an electromagnetic radiation 23 excites the element 10 for internal and external patches 12, 11. The coupling through a groove 21 is useful on the average that such an arrangement does not require a feeding or welding wire, although it adds another layer. The use of this structure of feeds can show a better performance of the axial relationship over wider angular intervals of elevation and improved bandwidth performance. Essentially, the combination of the slot 21 and the feed line 22 (at one of its ends after the slot) open circuit provides a higher order circuit load equivalent to the feed line 22. The slot acts as a Serial transformer and the open circuit termination of power line 22 acts as a series inductor and parallel capacitor load. All these degrees of extra freedom allow for improved flexibility in adapting the structure.

An advantage of the alternative feed arrangements is that they offer additional degrees of freedom and act to effectively build higher order adaptive network features that can help compensate for the resonance equivalent feed reactance deactivated over an increased bandwidth in comparison with the single unique feed characteristic described. Additional adaptation features are determined precisely as part of the same design methodology of mathematical electromagnetic optimization described previously.

The particular arrangement of the radiating elements 10 in the plate 3, according to the present invention, creates the effect of circular polarization. Accordingly, an antenna 1 incorporating the radiating element plate 2 of the present invention will operate through circular polarization. The example shown in the attached figures provides a right circular polarization, although an expert will recognize that a simple reorganization of the elements 10 will provide a left polarization.

When the radiating element plate 2 is in use on a GNSS antenna 1, the individual power plugs 16 connect each of the elements 10 to a circuit board 3, which is part of a circular polarization formation network such as the shown in Figure 6. The network combines the input of each of the

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elements 10 that are rotated 90 degrees from its neighbor, to provide a common output of antenna 1, preferably through a TNC connector 9 provided in antenna base 5, as shown in Figure 1. Antenna 1 It can be connected to an external preamp box (not shown) by means of a short RF quality cable that is ideally, but not essentially, less than 300 mm in length. Alternatively, the preamplifier can be integrated directly with the structure, preferably with the polarization formation network plate.

Many physical implementations are possible but any compatible network with that shown in Figure 6 will suffice, provided it can cover the necessary frequency bands.

Low dispersion implementations are always important to ensure that the antenna group delay is not compromised 1. The minimum connection of a suitable network with the radiating element plate 2 is important for proper function.

The advantages of forming the radiant element plate 2 as described above are twofold. First, it allows a single feed per element 10 to still produce a good quality RHCP when the elements 10 are fed with signals with a progressive phase sequence, and, secondly, a radiation pattern with significant coverage for directions near the horizon, as shown in Tables 7 (a) and 7 (b). The good coverage in directions close to the horizon is also the result of the precise sequential grouping arrangement of the elements 10 and the fact that the effective points where the radiation is emanating are confined only in the space between adjacent elements 10 and not through of both opposite edges for each of the elements 10 as in conventional GNSS patch antennas.

Figure 8 (a), and also Figure 8 (b) showing the area of the circle of Figure 8 (a) in more detail, show the performance of the radiation patterns measured in relation to the EUROCAE template for GNSS antennas of multiple future standards. These templates on the one hand ensure that the antenna is sensitive over a wide angular range in the hemisphere of higher radiation and on the other hand the radiation is not stronger than that required in order to minimize the susceptibility of the GNSS system to unwanted strong emissions of external interference sources. As you can see, this provision works well in both aspects. However, antenna 1 is expected to fit other pattern templates of the GNSS system in present or evolved forms.

The radiating elements 10 of the present invention are required to have a thickness that depends on the desired frequency and the bandwidth requirements for an antenna. However, for many applications, the elements 10 are required to be of a thickness that cannot be manufactured as a single block by conventional methods. Therefore, two separate blocks are manufactured to provide an upper layer with a patch 11 provided therein and a lower layer with a patch 12 provided therein. These layers can then be preferably fixed using conductive adhesive, although other suitable conductive joining means may be used, to form a radiant element 10 having the necessary thickness.

When conductive adhesive is used it is important that it has substantially the same thermal expansion properties as the material of the radiating element 10. The top layer, although substantially the same width as the bottom layer, is shorter in length than the bottom layer, providing therefore a step on which a part of the internal patch 12 can be exposed when the two layers are connected to form the radiant element 10. In addition, in addition to having the external patch 11 printed on its upper surface, the upper layer also has a dummy lower patch printed on its lower face, which is used to match the upper layer with the internal patch 12 provided on the lower layer when the two layers are fixed together. In this way the short circuit path forms a continuous low resistance path that conductively connects the upper patch 11, the lower patch 12 and the base plate 2. Similar effects are ensured for the path or feed wires.

As explained above, the elements 10 are arranged on the circuit board 3 with each element 10 that is rotated 90 degrees from its neighbor, with all the elements 10 that are rotated in the same direction. In addition, there is a gap between each element 10, which allows the teeth 15 in the external and internal patches 11, 12 to be easily removed to fine tune the apparatus. An additional benefit of these gaps is that they allow radiation to escape between the elements 10, rather than just around the outer edges, and this results in the formation of good radiation patterns.

The antenna 1 is manufactured using several multi-layer PCB elements. Since the bandwidth requirement is very large, the PCB, in this case, is created from three PCBs that are joined together using a stamped conductive joint film. The PCB is made as a complete block, but with mechanized grooves to separate the four radiating elements and to expose the tuning teeth 15 over the lower patch.

An alternative construction approach will be to make the entire element plate 2 of a single multilayer PCB with through holes plated through the entire element plate 2. This depends on the capacity of the PCB manufacturer and is dependent on factors such as the specific thickness of the PCB and the aspect ratio of the plated through holes.

The antenna described herein is designed to operate in the GPS L1 band and Galileo E5a and E5b bands. However, one skilled in the art understands that simple tuning of the antenna design allowed it to operate in alternative GNSS bands, for example L1 / L2 or L1 / L3.

Claims (18)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 1. A radiating element plate (2) for use in a passive antenna, the radiating element plate comprising a plurality of multi-layer radiating elements (10), each of which comprises: a first patch (11) provided in a first layer to receive signals within a first frequency band; Y a second patch (12) provided in a second layer to receive signals within a second frequency band, wherein the plurality of radiating elements is arranged on the radiating elements plate so that each radiating element is rotated sequentially at a predetermined angle from its neighboring element, all elements that are rotated in the same direction and in the same plane, wherein each patch is shorted to ground along one edge of the patch so that multi-band radiation can escape only from a virtual slot provided substantially along the opposite edge of the corresponding patches; characterized in that each patch (11, 12) has serrated teeth (15) provided along a first edge opposite the shorted to ground edge for broadband and tuning purposes. 2. The radiating element plate (2) according to claim 1, wherein the first and second patches (11, 12) on each radiating element are separated by dielectric material (13). 3. The radiating element plate (2) according to claim 1 or 2, wherein the dielectric material (13) is in stratified form. 4. The radiating element plate (2) according to any preceding claim, wherein the predetermined angle that each element is rotated from its neighboring element is 90 degrees. 5. The radiating element plate (2) according to any preceding claim, wherein each patch (11, 12) is shorted to ground by a plurality of plated through holes provided along the edge of the patch. 6. The radiating element plate (2) according to claim 5, wherein the short circuits are aligned in each of the patches (11, 12) comprising a radiating element (10). 7. The radiating element plate (2) according to any preceding claim, wherein each radiating element further comprises a power structure that connects it, in use, to a polarization formation network circuit board. 8. The radiating element plate (2) according to claim 7, wherein the feed structure comprises a substantially coaxial cylinder which can pass through a feed pin, or comprises one or more discs that a feed pin can pass through, or It comprises one or more posts provided at the base of the element, or comprises a groove at the base of the element through which electromagnetic radiation is propagated. 9. The radiating element plate (2) according to any preceding claim, wherein the first patch (11) receives GPS signals from NAVSTAR, and / or the second patch (12) receives GPS signals from Galileo. 10. The radiating element plate (2) according to any preceding claim, wherein the first frequency band is L1 (1,565-1,585 MHz), L2 (1,227 MHz), L3 (1,381 MHz) or L5 (1,176 MHz). 11. The radiating element plate (2) according to any preceding claim, wherein the second frequency band is 1,166-1,211 MHz (E5). 12. The radiating element plate (2) according to any preceding claim, which further comprises a preamplifier connected to the polarization formation network. 13. The radiating element plate (2) according to any preceding claim, which is sealed within a radome (4). 14. A plate of radiant elements (2) according to claim 13, wherein the radome (4) is filled with foam around the elements (10). 15. A plate of radiator elements (2) according to any preceding claim, wherein each radiator element (10) is constructed of an upper layer with an external patch (11) provided thereon and a lower layer with an internal patch (12) provided on it, the two layers that are provided separately before being joined together to form the radiant element using a suitable conduction means. 16. A plate of radiator elements (2) according to claim 15, wherein a dummy metallization surface is formed on the lower face of the upper layer and this joins an upper surface of the lower layer to join the two layers between its 17. A plate of radiator elements (2) according to claim 15 or 16, wherein the upper layer and the lower layer 5 of each radiator element are joined together using a conductive adhesive. 18. A radiator comprising a plate of radiant elements (2) according to any preceding claim.