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    • 专利摘要:
    A device radiating in two distinct frequency bands, a high frequency band and at least one subband of a low frequency band, said device being characterized in that it comprises: • at least one patch element (101 ) adapted to the high frequency band and connected to a first port (109), • at least one slot-like element (601) adapted to the low frequency band and connected to a second port (105), • a filter ( 110) positioned between said patch element and said first port, configured to filter the subband of the low frequency band and be on the high frequency band, and in that its size is smaller than that of a edge square λ / 2, where λ is the wavelength corresponding to the maximum operating frequency of the device.
    公开号:FR3045219A1
    申请号:FR1502559
    申请日:2015-12-09
    公开日:2017-06-16
    发明作者:Olivier Maas
    申请人:Thales SA；
    IPC主号:
    专利说明:

    MULTI-BAND ELEMENTARY RADIANT CELL
    The present invention is in the field of radiant devices designed to operate in two distinct frequency bands. It applies in particular to the two-band radiating cells made in printed technology, and used by radar with electronic scans for the surveillance of the airspace. These radars operate in S-band, and in the band dedicated to IFF applications (acronym for "Identification, Friend or Foe", or friendly or enemy identification).
    The electronic scanning radars of the state of the art consist of directional antennas made from radiating elements, or radiating cells, assembled within a network. The modification of the amplitude and the phase of each of the radiating elements of the network makes it possible to orient the direction of the radar beam.
    The frequencies of interest for aerial surveillance applications are the S band, used for primary radar, and in particular the 2.9GHz sub-band at 3.3GHz, as well as frequency bands of a few MHz or tens of MHz around it 1.03GHz and 1.09GHz frequencies, and used for IFF applications. Current radar equipment, whether ground-based radars or on-board radars such as a vehicle, a ship or an aircraft, generally comprise two independent systems: a rotary directive antenna dedicated to IFF applications and a Radar cell network for the S-band radar. The rotating antenna is positioned above or beside the S-band radar antenna. The two volumes are therefore added, which can be a problem during transport or installation of antennas. The invention seeks to solve the general problem of the multiplication of systems by proposing a radiating cell operating simultaneously and without interference, in two distinct frequency bands, in particular the band S and the frequency band dedicated to IFF applications. Such a cell makes it possible to achieve a dual-band radiating network, thereby reducing the overall size of the radar system, as well as the complexity of installation and the associated use constraints. The invention proposes a radiating cell for which the accesses to the different frequency bands are independent, which makes it possible to integrate the invention into the radar devices that exist in a transparent manner. The use of bi-band or broadband radiating elements within radiating networks is a frequently encountered problem.
    It is all the more complex that, when radiating elements are close, strong coupling phenomena appear. These coupling phenomena are all the more marked when the ratio of the frequencies between the high band and the low band approaches an odd integer. Indeed, the radiating elements are dimensioned with respect to the wavelength at which they operate. An element sized to radiate in the low frequency band will generally have a size close to Xb / 2, with Xb the maximum wavelength of the low frequency band. From the ratio of the frequency bands, its size will also be N.Xh / 2, with N the ratio of the frequency bands and Xh the maximum wavelength of the high frequency band in the dielectric. As a result, when N approaches an odd integer, the device also radiates for the high frequency band, thereby amplifying the coupling phenomena.
    The use, within the same radiating cell elements specific to each of the operating bands, separated by a gap to minimize problems of coupling between elements, is not a solution to the problem when the radiating cell is implemented in a radiating network. Indeed, the size of the cell is constrained by the pitch of the mesh of the network, which is generally X / 2, with λ the wavelength in the air corresponding to the maximum frequency. Thus, when the frequency ratio between the high frequency band and the low frequency band increases, the radiating elements required by the low frequency band become incompatible with the size of this networking step. For example, the networking pitch of a radiating mesh S band at 3.3GHz is about 5cm. A patch adapted to the band S, when made in the context of a substrate having a relative dielectric constant of 3.55, has dimensions of the order of 25mm x 25mm, compatible with the networking step. A patch for IFF applications, because of the ratio of frequency 3 between the two bands, will be 3 times larger (and 9 times greater surface area). It will then have a size of 75mm x 75mm. A device comprising an S band patch and a patch for IFF applications will therefore not be compatible with the pitch of the radiating mesh.
    A first known solution to the problem of producing a dual-band cell of reduced size is to use a single broadband radiating element. Once networked, the result is then a single broadband network, covering all bands of interest. However, the realization of such a radiating element proves complex when the band gap increases, and does not meet the need for independent access to each of the frequency bands.
    In order to answer the problem of the size of the network, a known solution consists in using, for the low frequency band, elements of the folded monopole or dipole type, or folded slots so as to be able to accommodate them in a reduced area. The simultaneous use of a patch for the high frequency band, and a slot for the low frequency band is of practical interest, because the slot can be housed in the metallization of the patch, or in that of its plane. mass. Various solutions of this type have been explored, but they come up against the fact that, under these conditions, the radiating slots have a very narrow bandwidth, which limits their interest. The article "A Dual Band Quasi-Magneto-Electric Antenna Patch for X-band Phased Array", S.E. Valavan, Proceedings of the 44th European Microwave Conference 2014, has gone beyond this limitation using the coupling phenomena between the two elements. It proposes to disturb a radiating patch in the high frequency band using a slot housed inside the radiating surface of the patch. The response of the device, resulting from the coupling between the two elements, has an operation in two distinct frequency bands whose central frequencies are distant from a ratio 1.5, but having significant bandwidths (greater than 5%).
    However, such a device has two major defects: • the band ratio is 1.5, which does not meet the radar band S and IFF applications, for which the frequency band ratio is 3, • it does not respond to need to have two separate antennas each connected to a separate access, because it offers a coupled system having two resonance bands. The amplitudes and phases of the radiating elements associated with the frequency band can not then be controlled independently. In addition, the integration of such a cell in existing equipment requires the separation between these two bands, to separately drive the high and low frequency band signal. This separation requires the realization of additional equipment at the interface between the radiating network and the radio equipment. It can be tricky, the quality of the resulting signals depending on the cleanliness of the filtering implemented. The invention addresses the problem by associating a radiating element in the patch-type high frequency band with at least one radiating element in the folded-slot low frequency band. This approach makes it possible to house the two radiating elements in a small, compatible cell of a network of unit elements operating at the high frequency.
    The elements of the high frequency band (patch) and the low frequency band (slot) are each connected to a separate access, which allows them to be controlled independently in amplitude and phase. Filters adapted to each of the frequency bands are implemented on each of the accesses, so as to eliminate the undesirable contributions related to the coupling resulting from the proximity between the radiating elements. The invention therefore consists of a device radiating in two distinct frequency bands, a high frequency band and at least one subband of a low frequency band. It is characterized in that it comprises: at least one patch element adapted to the high frequency band and connected to a first access, at least one slot element adapted to the low frequency band and connected to a second access, • a filter positioned between said patch element and said first port, configured to filter the low frequency band and be on for the high frequency band, and in that its size is smaller than that of a edge square λ / 2, where λ is the wavelength corresponding to the maximum operating frequency of the device.
    Advantageously, the slot-type element is housed in a ground plane of the device.
    Advantageously, said one or more slot-like elements are U-shaped folded slots and positioned at the periphery of the device.
    According to one embodiment of the device, the number of slot-like elements is equal to the number of sub-bands of the low frequency band, said slot-like elements being fed by the same second access.
    According to another embodiment of the device, the number of slot-like elements is equal to the number of sub-bands of the low frequency band, said slot-type elements being fed by different accesses.
    According to another embodiment, the device comprises a single slot-type element powered by said second access to which it is connected by a resonator circuit, the coupling between said slot and said resonator circuit being adjusted to radiate in two distinct sub-bands of the low frequency band.
    Advantageously, in this embodiment, the resonator circuit is a parallel resonator circuit comprising an inductor and a capacitor. The resonator is connected to the slot-like element by a waveguide of length λ / 4, where λ is the wavelength associated with the center frequency of the low frequency band.
    Advantageously, in all of the embodiments, the filter positioned between the patch-type element and the first port comprises a plurality of microstrip line sections of different widths.
    This property allows it to radiate only for one of the frequency bands when they are multiples of one another.
    Advantageously, the device further comprises a low-pass filter positioned between said one or more slot-like elements and said second port, and configured to filter the high frequency band.
    Advantageously, the device further comprises a second patch-type element adapted to the high frequency band, said second patch-type element being disposed above said first patch-type element.
    The device according to the invention can be implemented in a multilayer printed circuit for which said patch-type element, said slot-type element or elements, and said filter positioned between the patch-type element and the first access are in different layers of the printed circuit.
    This layer distribution makes it possible to limit as much as possible the surface area of the printed circuit. It is possible because the radiating elements do not hide, the slot-type element or elements being positioned at the periphery of the printed circuit, and therefore of the patch-type element.
    Thanks to the filtering element of the high frequency band, the device according to the invention is adapted to operate when at least one frequency of the high frequency band is an odd integer multiple of a frequency of the frequency band low.
    The device according to the invention is adapted to operate when the high frequency band comprises the 2.9 GHz - 3.3 GHz band.
    It is also adapted to operate when at least one subband of the low frequency band is centered around a frequency selected from the 1030 MHz frequency and the 1090 MHz frequency.
    The device according to the invention can easily be realized in printed technology.
    Finally, the invention relates to a radiating network configured to radiate in two distinct frequency bands, and characterized in that it comprises radiating cells conforming to the radiating device in two distinct frequency bands according to the invention.
    It also addresses a scanning radar configured to operate simultaneously in two different frequency bands, and characterized in that it comprises a radiating network as described by the invention. The invention will be better understood and other features and advantages will appear better on reading the description which follows, given in a non-limiting manner, and thanks to the appended figures in which: • Figure 1 represents a radiating cell in a first mode Embodiment of the Invention, FIG. 2 represents the exploded view of a radiating cell according to the first embodiment of the invention, FIGS. 3a and 3b show an example of reflection coefficient of the inputs and decoupling. respectively in the low and high frequency bands associated with each input of a radiant cell according to the first embodiment of the invention, • Figures 4a and 4b show an example of diagrams of the input associated with the low frequency band of a radiating cell according to the first embodiment of the invention, FIGS. 5a and 5b show an example of radiation diagrams of the input associated with the high frequency band of a radiating cell according to the first embodiment of the invention, FIG. 6 represents a radiating cell according to a second embodiment embodiment of the invention, • Figures 7a and 7b show an example of input reflection coefficient and decoupling, respectively in the low frequency band and in the high frequency band, associated with each input of a radiating cell According to the second embodiment of the invention, FIGS. 8a and 8b show an example of radiation diagrams of the input associated with the high frequency band of a radiating cell according to the second embodiment of the invention. • Figures 9a and 9b show an example of radiation diagrams of the input associated with the high frequency band. a radiating cell according to the second embodiment of the invention, • Figure 10 shows a radiating cell according to a third embodiment.
    The descriptions of the embodiments set out below are dedicated to a particular mode of operation of the invention. This mode of operation meets the needs of radar applications for the surveillance of airspace. The radiating cell presented below seeks to operate in a dissociated manner in the band 2.9 GHz - 3.3 GHz (subband of the band S dedicated to radar applications), as well as in two sub-bands of a few MHz in the frequency band. dedicated to IFF applications, a first centered around the 1030MHz frequency and a second centered around the 1090MHz frequency. These two sub-bands correspond to the IFF applications' return and return channels.
    However, the invention is not limited to this operation or to this type of applications, and can be extended mutatis mutandis to other frequency bands, or to other embodiments in which the number of subbands chosen within the low frequency band varies.
    In the examples presented, the ratio of the frequency bands, that is to say the ratio between the frequencies of the high frequency band and the frequencies of the low frequency band, is about three. As a result, the coupling phenomena between the various radiating elements, introduced by their physical proximity, are reinforced. This is because, when the frequency ratio between the bands is an odd integer, all the line-based resonant structures function naturally identical to the frequency fo and all its odd multiples. As a result, radiating elements sized for IFF applications also radiate for the S-band.
    FIG. 1 represents a radiating cell according to a first embodiment of the invention. This radiating cell 100, or antenna with printed radiating elements, is a printed circuit comprising multiple layers separated by a dielectric substrate, using distributed elements, that is to say microstrip lines (also referred to as "microstrip"). "). This technology is widespread in microwave because, for high frequencies, the manipulation of waves from waveguides is simpler than handling currents and voltages. One of the layers of the printed circuit forms a ground plane.
    The radiating cell comprises a radiating element 101 of the patch type. In distributed elements, a patch is a metallized layer of square or rectangular fed form. The dimensions of the patch are chosen so that it radiates in the high frequency band (band S). It is positioned in one of the layers of the circuit.
    The radiating cell also comprises two radiating slots 102 folded. These slots have the behavior of dipoles, while being less sensitive to coupling phenomena. They are tuned to operate around subbands of interest in the low frequency band (in the example, 1030MHz and 1090MHz). This agreement is made by sizing them with respect to the desired wavelength, the slot then having a length of 7J2. The number of slots is adapted to the number of low frequency bands desired. The use of two folded U-shaped slots and a patch antenna makes it possible to house the three radiating elements in a very small environment.
    The slots are made by partial de-metallization of the ground plane of the cell. The excitation of the slots is performed by a radiating ribbon 103 positioned between the two slots in one of the planes of the printed circuit, preferably the plane adjacent to the ground plane, and connected to the power supply of the slots. The relative positioning of the two slots 102 and the exciter 103 creates coupling phenomena, both between the elements of the low frequency band, but also with the patch 101. Their positioning must therefore be adjusted in order to repel the artifacts. generated by this coupling outside the useful bands. The adjustment of the gap between the slots makes it possible to adjust the resonance frequency of each slot and to postpone their operation on the triple frequency outside the high frequency band. The exciter 103 is powered by the low frequency band access 105, to which it is connected by a coaxial line 104 and a low pass filter 106.
    This low-pass filter comprises, for example, two capacitors 107, which in printed technology take the form of open line sections.
    The filter serves to filter the components of the high frequency band due to the strong coupling between the slots and the patch. The patch-type radiating element 101 is powered by the high frequency band access 109 to which it is connected by a coaxial line 108 and a filter 110.
    The filter 110 serves to filter the components of the low frequency band due to the strong coupling between the slots and the patch.
    Achieving a high-pass or bandpass filter requires a series of series capacitances and parallel inductances difficult to achieve in distributed technology, and the size of the components, related to the low frequency band, presents the problem of the footprint. An alternative way to achieve a band pass filter is then to insert one or more short-circuited parallel waveguides, better known as the English stub.
    A parallel waveguide acts as a series resonator circuit, and has a very small footprint. Its length is proportional to the wavelength in the dielectric of the frequency that it is short-circuiting. Thus, a stub made from a section of microstrip line of length λβ / 4, with λβ the wavelength of the low frequency band, will play the role of short circuit in its resonance band. In the example, this is the low frequency band. However, the line-based resonant structures naturally function in the same way at the frequency f0 and for all the odd multiples of this frequency. This is the case in the example, where the ratio of the frequency bands is 3. Thus, such a stub will also play the role of short circuit for the high frequency band.
    This problem is solved by implementing a stub whose total length is divided into several different impedance sections (known in English as "stepped impedance") variable. Such a stub is dispersive. It is sized to have a short circuit on its fundamental frequency, and an open circuit on its triple frequency. The filter 110 of Figure 1 has such a stub, consisting of several sections of microstrip line of different widths, and thus having several distinct impedances. In the example, it presents three different impedances, but the number of sections is a parameter specific to each implementation. Because of the variable impedances, the system is not homogeneous, its electrical length no longer linearly depends on the frequency. Its size being λβ / 4, it is tuned to block the components in the low frequency band, but is no longer adapted to the electrical length 3.λπ / 4. It then realizes the desired functions of filtering the components of the low frequency band while letting the components of the high frequency band pass.
    The various elements constituting it are arranged in different layers of the printed circuit. FIG. 2 represents the exploded view of a radiating cell according to the first embodiment of the invention, in which the arrangement of the elements is intended to limit the size of the radiating cell.
    In this non-limiting example, the printed circuit comprises four layers. Each of the layers comprises a dielectric substrate on which is deposited an etched metal layer. The upper layer 201 comprises the patch element 101 tuned to operate in the high frequency band.
    The immediately lower layer 202 comprises the ground plane of the radiating cell, wherein two slot-like elements 102, tuned for the low frequency bands, are made by demetallizing the ground plane. The slots are arranged so as not to be obstructed by the patch 101. An advantageous positioning then consists of placing them at the periphery of the radiating cell, opposite the patch.
    The lower layer 203 comprises the exciter of the slots 103. Finally, the lowest layer 204 comprises the low-pass filtering element 106 connected on the one hand to the access 105 and on the other hand to the exciter 103 by the through a coaxial line, described under the reference 104 in Figure 1, allowing it to pass through the different layers of the printed circuit, and the band pass filter elements 110 connected on the one hand to the access 109 and other part of patch 101 through a coaxial line 108.
    The resulting radiating cell has a slightly larger format than the S-band patch format. For example, in the specific case of operation for the S-band and IFF applications, the size of the S-band patch is 25mm x 25mm. . The resulting radiating cell of the first embodiment holds in a footprint of 45mm x 45mm, that is to say h / 2 x h / 2.
    This cell radiates simultaneously in the upper frequency band and in the lower frequency band, but has separate access to each of these bands. The different filtering elements make it possible to ensure a strong decoupling between the two accesses.
    Advantageously, it is possible to complete the radiating cell with an additional layer 205, comprising a second patch antenna 206 adapted to the high frequency band. This additional layer is positioned on the highest layer 201, the second patch being superimposed on the first patch 101. This addition makes it possible to increase the bandwidth in the high frequency band, by playing on the coupling effects between the two patches. without changing the size of the cell.
    FIGS. 3a and 3b show an example of input reflection coefficient and decoupling coefficient, respectively in the low frequency band and in the high frequency band associated with each input of a radiating cell according to the first embodiment of the invention. 'invention.
    The results are obtained by simulations using electromagnetic simulation software using the finite element method.
    The reflection coefficient of the inputs is representative of the power of the signal reflected as a function of frequency. When this coefficient tends to 1 (or OdB), then the whole power of the signal at the frequency concerned is rejected. The lower the coefficient, the better the antenna.
    Decoupling measures the power of leakage in a first antenna when the second antenna operates and vice versa. It is therefore representative of the cohabitation performance of the two types of radiating elements within the same cell.
    In FIG. 3a, the curve 301 represents the reflection coefficient of the access dedicated to the low frequency band, for the low frequency band (the frequency subbands envisaged in this embodiment are bands of a few MHz or tens of MHz around 1.03GHz and 1.09GHz frequencies). This coefficient is less than -10dB around the 1.03GHz and 1.09GHz frequencies. Dedicated access to the low frequency band is therefore suitable for IFF applications.
    The curve 302 represents the reflection coefficient of the access dedicated to the high frequency band, for the low frequency band. In the band 1.02GHz - 1.12GHz, this coefficient is constant, and is equal to 1 (or OdB). Dedicated access to the high frequency band therefore rejects all the components of the low frequency band. It is not affected by the coupling with the radiating elements in the low frequency band. This analysis is confirmed by the measurement of the decoupling 303 between the two inputs, which is greater than 24 dB throughout the band.
    In FIG. 3b, the curve 311 represents the reflection coefficient of the access dedicated to the low frequency band, for the high frequency band (the frequency band envisaged in this embodiment is the band 2.9 GHz - 3.3 GHz ). This coefficient is constant, and is equal to 1 (that is to say OdB). Dedicated access to the low frequency band therefore rejects all the components of the high frequency band. It is then not affected by the coupling with the radiating elements in the high frequency band.
    The curve 312 represents the reflection coefficient of the access dedicated to the high frequency band, for the high frequency band. In the band 2.9GHz - 3.3GHz, this coefficient is less than -12.5dB. Dedicated access to the high frequency band is therefore adapted to this frequency band. The decoupling 313 between the 2 antennas is greater than 25 dB in the band.
    FIGS. 4a and 4b show an example of radiation diagrams of the input associated with the low frequency band of a radiating cell according to the first embodiment of the invention.
    FIG. 4a shows the radiation pattern in the horizontal plane of the access to the low frequency band, for a frequency of 1.03GHz in main polarization (401) and crossed (403), as well as for a frequency of 1.09GHz in main (402) and cross polarization (404). The cross polarization response in this plane is almost zero (-30dB).
    The main polarization of a radiating element is the axis on which the radiated electric field is maximum. Cross polarization is the axis perpendicular to the axis of the main polarization. These two axes lie in the plane perpendicular to the direction of propagation.
    In the case of the device according to the invention, the main polarization is in the vertical plane (represented by the y axis in the figures), while the crossed polarization is in the horizontal plane (represented by the x axis on the figures).
    Figure 4b shows the vertical low-frequency radiation pattern for a frequency of 1.03GHz (411) and 1.09GHz (412). In this plane, the level of cross polarization is almost zero.
    The radiation patterns observed on the access to the low frequency band in the horizontal and vertical plane vary in cosine Θ for the main polarization, where Θ is the direction of observation. This characteristic is necessary for the realization of an electronic scanning antenna.
    FIGS. 5a and 5b show an example of radiation diagrams of the input associated with the high frequency band of a radiating cell according to the first embodiment of the invention.
    Figure 5a shows the radiation pattern in the horizontal plane of access to the high frequency band, for a frequency of 2.9GHz in main (501) and cross (502) polarization. The cross polarization response is small compared to the main polarization response (typically 15dB at 30dB difference).
    Figure 5b shows the radiation pattern in the vertical plane of access to the high frequency band, for a frequency of 2.9GHz in main polarization (511). The cross polarization response in this plane is negligible.
    The radiation patterns observed in the high frequency band are characteristic of the radiation pattern of a patch. Indeed, this diagram has a variation close to a cosine function Θ, necessary for the realization of an electronic scanning antenna.
    FIG. 6 represents a radiating cell according to a second embodiment of the invention. This mode of operation limits the number of sub-bands in the low frequency band to two.
    Similarly to the first embodiment, the radiating cell 600 designed according to the second embodiment of the invention comprises a patch-type radiating element 101 tuned to the upper frequency band. This radiating element is fed by the high band output 109 to which it is connected via a coaxial line 108 allowing it to pass through the different layers of the printed circuit, and a filter 110 made in the form of a stub having a plurality of variable impedance sections for filtering the low frequency band while passing for the high frequency band. Advantageously, a second patch-like element, identical to the first, may be superimposed on the first patch-type element 101, to widen the bandwidth in the high frequency band.
    The main difference between this embodiment and the first consists in that it contains only a single element of slot type 601, folded in U, and positioned to be disengaged with respect to the masking represented by the patch or patches 101 The operating band of this element is then widened to the whole of the low frequency band, in order to understand the two subbands required by the IFF applications, by the association of a resonator 602. The radiating slot, which forms a parallel resonator, can be completed by a series resonator placed in the output plane, or by a parallel resonator placed a quarter of a wavelength further. The resonator 602 is then placed at a distance Li from the connector 104 connecting it to the exciter 103 of the slot, Li equaling λ / 4, where λ is the central wavelength of the low frequency band.
    Slot 601 is not given to one of the sub-bands of the low frequency band, but to the central frequency, that is, in the case of the example chosen, the frequency 1.06GHz. Resonator 602 is also designed to resonate at this center frequency. The action on the coupling between these two elements, ie the mismatch created between these two elements, will make them resonate around the desired frequencies. The coupling between the two elements is adjusted by varying the position of the exciter 103 of the slot. The slot 601, the resonator circuit 602 and the exciter 103 are therefore dimensioned and positioned so that the assembly resonates around the 1030 MHz and 1090 MHz frequencies, while allowing a strong mismatch in the intermediate frequency zone. The radiating element thus obtained is bi-frequency. This approach offers the advantage of only introducing a single radiating slot in the cell, and reducing the interference between the slot and the patch, and thus the coupling phenomena in the low frequency band and the high frequency band. . The positioning of the slot 601 and the exciter 103 is thus simplified with respect to the first embodiment.
    In FIG. 6, the resonator circuit 602 is of parallel capacitance and inductance type. The inductor 603 is of low value. It is in the form of a microstrip line of length L2 connected to ground. The capacitor 604 is made in the form of a short-circuited microstrip line of length L3, L3 being much greater than L2.
    Advantageously, a low pass filter similar to the filter 106 of the first embodiment of the invention can be added to filter the components of the high bands linked to the coupling between the slot and the patch. Such a filter is however not essential in the second embodiment, the resonator circuit naturally performing the role of low pass filter.
    In the second embodiment, the reduction in the number of radiating elements (slots) is compensated by an additional effort on the microwave circuit for adapting the slot.
    FIGS. 7a and 7b show an example of reflection and decoupling coefficient associated with each input of a radiating cell according to the second embodiment of the invention. The results are obtained by simulations using electromagnetic simulation software using the finite element method.
    In FIG. 7a, the curve 701 represents the reflection coefficient of the access dedicated to the low frequency band for the low frequency band (the frequency bands envisaged in this embodiment are bands of a few MHz or tens of MHz around 1.03GHz and 1.09GHz frequencies). This coefficient is near or below -10dB around 1.03GHz and 1.09GHz. Dedicated access to the low frequency band is therefore suitable for IFF applications.
    Curve 702 represents the reflection coefficient of the access dedicated to the high frequency band, for the low frequency band. In the band 1GHz - 1.15GHz, this coefficient is constant, and is equal to 1 (or OdB). Dedicated access to the high frequency band therefore rejects all the components of the low frequency band. It is not affected by the coupling with the radiating elements in the low frequency band. The decoupling 703 between the slots of the slot and the patch is of the order of 30 dB.
    In FIG. 7b, the curve 711 represents the reflection coefficient of the access dedicated to the low frequency band, for the high frequency band (the frequency band envisaged in this embodiment is the band 2.9 GHz - 3.3 GHz ). This coefficient is almost constant, and is equal to 1 (or OdB) over almost the entire band. The dedicated access to the low frequency band therefore rejects all the components of the high frequency band, it is not affected by the coupling with the radiating elements in the high frequency band.
    Curve 712 represents the reflection coefficient of the dedicated access to the high frequency band. In the band 2.9GHz - 3.3GHz, this coefficient is well below -12.5dB. Dedicated access to the high frequency band is therefore adapted to this frequency band.
    Decoupling 713 between the 2 antennas is greater than 12.5 dB in the band.
    FIGS. 8a and 8b show an example of radiation diagrams of the input associated with the low frequency band of a radiating cell according to the second embodiment of the invention.
    FIG. 8a shows the horizontal plane radiation pattern of the access to the low frequency band, for a frequency of 1.03GHz in main polarization (801) and crossed (803), as well as for a frequency of 1.09GHz in main (802) and cross polarization (804). The response according to the main polarization in this plane is almost zero (-30dB).
    Figure 8b shows the vertical low frequency access plane radiation pattern for a main polarization frequency of 1.03GHz (811) and a main polarization frequency of 1.09GHz (812) . In this plane, the cross polarization is negligible.
    The radiation patterns observed on the access to the low frequency band in the first and second plane vary in cosine Θ for the main polarization, Θ being the direction of observation. This characteristic is necessary for the realization of an electronic scanning antenna.
    FIGS. 9a and 9b show an example of radiation diagrams of the input associated with the high frequency band of a radiating cell according to the first embodiment of the invention,
    Fig. 9a shows the radiation pattern in the horizontal plane of access to the high frequency band, for a frequency of 2.9GHz in main (901) and cross (902) polarization. The cross polarization response is small compared to the main polarization response (typically 30dB difference).
    Figure 9b shows the radiation pattern in a vertical plane of access to the high frequency band, for a frequency of 2.9GHz in main polarization (911). There is no cross polarization response in this plane of the cell.
    The radiation patterns observed in the high frequency band are characteristic of the radiation pattern of a patch. Indeed, this radiation pattern in the foreground has a cosine variation Θ characteristic of a patch antenna, and necessary for the realization of an electronic scanning antenna.
    FIG. 10 represents a radiating cell according to a third embodiment of the invention. This is a variant of the first embodiment, which comprises a slot-type radiating element for each of the subbands envisaged in the low frequency band.
    This embodiment differs from the first in that the two slot-like elements 1001 and 1011 are dissociated and placed on each side of the patch-like element, always at the periphery of the radiating cell so as not to be masked by the patch. This distance between the two slots makes it possible to reduce the coupling phenomena between them. Each of the slots is tuned to the center frequency of one of the sub-bands of the low frequency band, and is connected to a separate access. The radiating cell then has three accesses: a first access to the high frequency band, and access for each of the sub-bands of the low frequency band.
    In this embodiment, the first slot 1001 is powered by the access 1003 to which it is connected via an exciter 1002, a coaxial line 1004, and a low pass filter 1005.
    In a completely identical manner, the second slot 1011 is fed by the access 1013 to which it is connected by means of an exciter 1012, a coaxial line 1014, and a low-pass filter 1015. The invention also comprises a radiating network made from two-band radiating cells as defined above. Each of the cells can then be driven in amplitude and / or in phase in each of the bands of interest, ie in the specific example, in the S band (and more particularly in the 2.9 GHz-3.3 GHz subband) and in the band dedicated to IFF applications (1.03GHz and 1.09GHz).
    Finally, it consists of a dual-band radar comprising a single electronic scanning antenna, the antenna being made from the radiating network described above, and operating independently in the two frequency bands.
    权利要求:
    Claims (17)
    [1" id="c-fr-0001]
    1. Apparatus radiating in two distinct frequency bands, a high frequency band and at least one subband of a low frequency band, said device being characterized in that it comprises: at least one patch element (101) adapted to the high frequency band and connected to a first port (109); • at least one slot-like element (102) adapted to the low frequency band and connected to a second port (105); a filter (110) positioned between said patch element and said first port, configured to filter the low frequency band and pass for the high frequency band, and in that its size is smaller than that of an edge square 7J2, where λ is the wavelength corresponding to the maximum operating frequency of the device.
    [2" id="c-fr-0002]
    2. radiating device according to the preceding claim, wherein said slot-like element (102) is housed in a ground plane of the device.
    [3" id="c-fr-0003]
    3. radiating device according to one of the preceding claims, wherein said one or more slot-like elements (102) are U-shaped folded slots and positioned at the periphery of the device.
    [4" id="c-fr-0004]
    4. radiating device according to one of the preceding claims, wherein the number of slot-type elements is equal to the number of sub-bands of the low frequency band, said slot-type elements being fed by the same second access.
    [5" id="c-fr-0005]
    5. radiating device according to one of claims 1 to 3, wherein the number of slot-type elements is equal to the number of sub-bands of the low frequency band, said slot-type elements being fed by different accesses .
    [6" id="c-fr-0006]
    6. radiating device according to one of claims 1 to 3, comprising a single slot-type element (601) supplied by said second port (109) to which it is connected by a resonator circuit (602), the coupling between said slot and said resonator circuit being adjusted to radiate in two distinct subbands of the low frequency band.
    [7" id="c-fr-0007]
    The radiating device according to claim 6, wherein said resonator circuit (602) is a parallel resonator circuit comprising an inductor (603) and a capacitor (604), said resonator being connected to the slot-like member (601) by a waveguide of length λ / 4, where λ is the wavelength associated with the center frequency of the low frequency band.
    [8" id="c-fr-0008]
    8. radiating device according to one of the preceding claims, wherein said filter (110) positioned between the patch element (101) and the first port (109) comprises a plurality of microstrip line sections of different widths.
    [9" id="c-fr-0009]
    The radiating device according to one of the preceding claims, further comprising a low-pass filter (106) positioned between said one or more slot-like elements (102) and said second port (105), and configured to filter the band of high frequencies.
    [10" id="c-fr-0010]
    The radiating device according to one of the preceding claims, further comprising a second patch-type element (206) adapted to the high frequency band, said second patch-like element being disposed above said first patch-type element.
    [11" id="c-fr-0011]
    11. radiating device according to one of the preceding claims, implemented in a multilayer printed circuit for which said patch-type element (101), said slot-type element (s) (102), and said filter (110) positioned. between the patch element and the first port are in different layers (201, 202, 203, 204) of the printed circuit.
    [12" id="c-fr-0012]
    12. radiating device according to the preceding claim, wherein at least one frequency of the high frequency band is an odd integer multiple of a frequency of the low frequency band.
    [13" id="c-fr-0013]
    13. The radiating device according to the preceding claim, wherein the high frequency band comprises the band 2.9 GHz - 3.3 GHz.
    [14" id="c-fr-0014]
    14. radiating device according to one of the preceding claims, wherein a subband of the low frequency band is centered around a frequency selected from the frequency 1030 MHz and the frequency 1090 MHz.
    [15" id="c-fr-0015]
    15. radiating device according to one of the preceding claims, made in printed technology.
    [16" id="c-fr-0016]
    16. A radiating network configured to radiate in two distinct frequency bands, characterized in that it comprises radiating devices according to one of the preceding claims.
    [17" id="c-fr-0017]
    17. Electronic scanning radar configured to operate simultaneously in two different frequency bands, and characterized in that it comprises a radiating network according to claim 16.
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    同族专利:
    公开号 | 公开日
    FR3045219B1|2017-12-15|
    ES2815698T3|2021-03-30|
    US20170170553A1|2017-06-15|
    EP3179557A1|2017-06-14|
    US10122076B2|2018-11-06|
    IL249390D0|2017-03-30|
    EP3179557B1|2020-06-17|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US20030164800A1|2002-03-04|2003-09-04|Jordan David Frederick|Multi-band antenna using an electrically short cavity reflector|
    WO2004102744A1|2003-05-14|2004-11-25|Koninklijke Philips Electronics N.V.|Improvements in or relating to wireless terminals|
    US20060208901A1|2004-02-27|2006-09-21|Manabu Kai|Radio tag|
    AU2015101429A4|2014-10-09|2015-11-12|Apple Inc.|Electronic device cavity antennas with slots and monopoles|
    CN106486775A|2016-11-25|2017-03-08|华南理工大学|A kind of low section double frequency-band filtering paster antenna and its composition mimo antenna|
    CN108493590B|2018-01-15|2020-02-11|深圳市信维通信股份有限公司|Antenna unit, MIMO antenna and handheld device|
    CN109378579A|2018-10-15|2019-02-22|钟祥博谦信息科技有限公司|A kind of filtering type slot antenna|
    CN110336130B|2019-04-29|2021-08-31|中天宽带技术有限公司|Dipole filtering antenna and electronic equipment|
    CN110401026B|2019-06-10|2021-03-23|西安电子科技大学|Magnetoelectric dipole filtering antenna with approximate elliptical filtering response|
    法律状态:
    2016-11-28| PLFP| Fee payment|Year of fee payment: 2 |
    2017-06-16| PLSC| Publication of the preliminary search report|Effective date: 20170616 |
    2017-11-27| PLFP| Fee payment|Year of fee payment: 3 |
    2019-11-28| PLFP| Fee payment|Year of fee payment: 5 |
    2020-11-25| PLFP| Fee payment|Year of fee payment: 6 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1502559A|FR3045219B1|2015-12-09|2015-12-09|MULTI-BAND ELEMENTARY RADIANT CELL|FR1502559A| FR3045219B1|2015-12-09|2015-12-09|MULTI-BAND ELEMENTARY RADIANT CELL|
    US15/365,580| US10122076B2|2015-12-09|2016-11-30|Multi-band elementary radiating cell|
    EP16201682.8A| EP3179557B1|2015-12-09|2016-12-01|Multi-band elementary radiating cell|
    ES16201682T| ES2815698T3|2015-12-09|2016-12-01|Elemental multiband radiant cell|
    IL249390A| IL249390D0|2015-12-09|2016-12-05|Multi-band elementary radiating cell|
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