Planar antenna with two chamfered radiating elements

Abstract

The planar antenna (10) comprises: - a support (20); - at least one first radiating element (40) mounted on the support (20) and comprising a conductive body (42) that is substantially rectangular or square; and - at least one layer of dielectric material (50) arranged on the at least one first radiating element (40). The planar antenna (10) further comprises at least one second radiating element (60) arranged on the at least one layer of dielectric material (50) opposite the at least one first radiating element (40) and comprising a conductive body (62) that is substantially rectangular or square, each of the conductive body (42) of the at least one first radiating element (40) and the conductive body (62) of the at least one second radiating element (60) comprising at least one vertex (44A, 64A, 64C) having a chamfer (48, 68).

Description

[0001] The present invention relates to a planar antenna comprising: a support; at least one first radiating element mounted on the support and comprising a substantially rectangular or square planar conductive body; and at least one layer of dielectric material arranged on the at least one first radiating element.

[0002] Planar antennas are used, for example, for long-distance communication (typically 36,000 km for a geostationary satellite). To prevent the polarization of transmitted and received waves from impacting link quality, it is preferable to use circularly polarized telecommunication waves. Indeed, the use of linear polarization can lead to losses, particularly in the case of phase shifts.

[0003] Many antennas inherently transmit and receive with linear polarization. For the aforementioned applications, an external polarizer is therefore added.

[0004] Such an external polarizer results in additional weight and bulk, as well as increased manufacturing costs.

[0005] One aim of the invention is therefore to offer a planar antenna that allows for good quality reception / transmission even over long distances while having a reduced weight and size.

[0006] To this end, the invention relates to an antenna, of the aforementioned type, further comprising at least one second radiating element arranged on at least one layer of dielectric material opposite at least one first radiating element and comprising a substantially planar rectangular or square conducting body, each of the conducting body of at least one first radiating element and of the conducting body of at least one second radiating element comprising at least one vertex having a chamfer.

[0007] Thanks to the overlapping radiating elements, improved performance is achieved over a wide frequency band. The chamfers on the radiating elements transform linearly polarized waves into circularly polarized waves.

[0008] According to other advantageous aspects of the invention, the planar antenna comprises one or more of the following features, taken individually or in any technically possible combination: at least one chamfer is such that the corresponding radiating element is capable of transforming a circularly polarized wave received by said radiating element into a linearly polarized wave and of transforming a linearly polarized wave to be emitted by said radiating element into a circularly polarized wave; at least one chamfer has a defined chamfer angle with a side of the corresponding square or rectangle between 30° and 120°; each of the conducting body of at least one first radiating element and of the conducting body of at least one second radiating element includes at least one curved vertex; at least one curved vertex has a radius of curvature between 0% and 50% of the length of a side of the square or rectangle of the corresponding conducting body;for each of the conducting body of at least one first radiating element and of the conducting body of at least one second radiating element: the conducting body comprises at least one vertex with a chamfer; the vertices other than the at least one vertex with a chamfer are curved; each radiating element has a direction of orientation, the direction of orientation of the at least one first radiating element and the direction of orientation of the at least one second radiating element forming an angle between 0° and 360°; the planar antenna is such that: the conducting body of the at least one first radiating element comprises a single vertex with a chamfer; the conducting body of the at least one second radiating element comprises two opposite vertices, each with a chamfer;The chamfer of the conducting body of at least one first radiating element is arranged opposite one or the other of the two chamfers of the conducting body of at least one second radiating element; each conducting body is made of a metallic material, for example copper, the dielectric material layer being made of epoxy resin or a derivative of polytetrafluoroethylene.

[0009] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which: [ Fig. 1 ] there figure 1 is a schematic illustration of a planar antenna according to the invention.

[0010] With reference to the figure 1 , a planar antenna 10 according to the invention is disclosed.

[0011] The planar antenna 10 comprises a support 20, at least one first radiating element 40, at least one layer of dielectric material 50 arranged on the at least one first radiating element 40 and at least one second radiating element 60.

[0012] Advantageously, the planar antenna 10 further comprises at least one layer of dielectric material 30 arranged between the support 20 and at least one first radiating element 40.

[0013] In what follows, a single first radiating element 40 and a single second radiating element 60 are described. Of course, the invention also applies in the case where the planar antenna 10 comprises several first radiating elements 40 and / or several second radiating elements 60.

[0014] Also, in what follows, a single layer of dielectric material 30 between the support 20 and the first radiating element 40 (called the lower dielectric material layer) and a single layer of dielectric material 50 between the first radiating element 40 and the second radiating element 60 (called the upper dielectric material layer) are described. Of course, the invention also applies in the case where the planar antenna 10 comprises several layers of dielectric material 30 between the support 20 and the first radiating element 40 and / or several layers of dielectric material 50 between the first radiating element 40 and the second radiating element 60.

[0015] Advantageously, the support 20 is conductive and constitutes a ground plane for the planar antenna 10.

[0016] For example, support 20 is made of a metallic material, for example copper. For example, a metallic finish can be applied to the surface of the metallic material of support 20, in particular a gold metallic finish.

[0017] For example, as illustrated on the figure 1 , the support 20 is formed by a conductive plate 22 extending along a horizontal plane PH.

[0018] For example, as illustrated on the figure 1 , the lower dielectric material layer 30 extends over the support 20, between the support 20 and the first radiating element 40.

[0019] Advantageously, the lower dielectric material layer 30 is made of epoxy resin or a derivative of polytetrafluoroethylene.

[0020] The first radiating element 40 is mounted on the support 20, in particular on the lower layer of dielectric material 30 itself applied to the support 20.

[0021] The first radiating element 40 comprises a conducting body 42 substantially rectangular or square planar, extending in particular substantially parallel to the horizontal plane PH.

[0022] In particular, the conductive body 42 is thin. By "thin", we mean that the conductive body 42 extends in three dimensions, one of these three dimensions (perpendicular to the horizontal plane PH) being much smaller than the other two.

[0023] For example, the first radiating element 40 has an orientation direction D1. For example, the orientation direction D1 is parallel to at least one side of the conducting body 42 (specifically sides 46CD and 46AB in the example of the figure 1 ).

[0024] Advantageously, the first radiating element 40 further includes at least one power supply access (not shown), for example a power line, a power slot or a conductive orifice.

[0025] In particular, the conducting body 42 of the first radiating element 40 is formed by a substantially flat rectangular or square plate.

[0026] In the example of the figure 1 , the conducting body 42 of the first radiating element 40 is square.

[0027] Advantageously, the conducting body 42 of the first radiating element 40 is made of a metallic material, for example copper.

[0028] The conducting body 42 of the first radiating element 40 has four vertices 44A, 44B, 44C, 44D connected by sides 46AB, 46BC, 46CD, 46DA.

[0029] At least one vertex 44A of the conducting body 42 of the first radiating element 40 has a chamfer 48.

[0030] Advantageously, at least one chamfer 48 is such that the first radiating element 40 is able to transform a circularly polarized wave received by the first radiating element 40 into a linearly polarized wave and to transform a linearly polarized wave to be emitted by the first radiating element 40 into a circularly polarized wave.

[0031] Even more advantageously, at least one chamfer 48 of the first radiating element 40 has a chamfer angle α1 defined with a side 46 of the square or rectangle corresponding to the conducting body 42 between 30° and 120°.

[0032] Advantageously, the conducting body 42 of the first radiating element 40 further comprises at least one curved vertex 49.

[0033] For example, at least one curved vertex 49 of the conducting body 42 of the first radiating element 40 has a radius of curvature R1 between 0% and 50% of the length of a side 46 of the square or rectangle of the conducting body 42.

[0034] Advantageously, the conducting body 42 of the first radiating element 40 comprises at least one vertex 44A having a chamfer 48, the vertices 44B, 44C, 44D other than the at least one vertex 44A having a chamfer 48 being curved.

[0035] In the specific example of the figure 1 , the conducting body 42 of the first radiating element 40 comprises a single vertex 44A having a chamfer 48, the other vertices 44B, 44C, 44D being advantageously curved.

[0036] Advantageously, the upper layer of dielectric material 50 extends between the first radiating element 40 and the second radiating element 60.

[0037] Advantageously, the upper dielectric material layer 50 is made of epoxy resin.

[0038] The second radiating element 60 is arranged on the upper dielectric material layer 50 opposite the first radiating element 40. The arrangement of the second radiating element 60 and the first radiating element 40 results in a so-called "stacked" structure. This structure allows for satisfactory transmission / reception performance over wide frequency bands while maintaining separate and geometrically orthogonal transmission and reception.

[0039] The second radiating element 60 comprises a conducting body 62 substantially rectangular or square planar, extending in particular substantially parallel to the horizontal plane PH.

[0040] In particular, the conductive body 62 is thin. Here too, by "thin" we mean that the conductive body 62 extends in three dimensions, one of these three dimensions (perpendicular to the horizontal plane PH) being much smaller than the other two.

[0041] Advantageously, the second radiating element 60 further includes at least one power access (not shown), for example a power line or a power slot.

[0042] For example, the second radiating element 60 has an orientation direction D2. For example, the orientation direction D2 is parallel to at least one side of the conducting body 62, in particular substantially opposite at least one side of the conducting body 42 with respect to which the orientation direction D1 is defined (in particular sides 66CD and 66AB in the example of the figure 1 ).

[0043] Advantageously, the orientation direction D2 of the second radiating element 60 and the orientation direction D1 of the first radiating element 40 form an angle β between 0° and 360°. A person skilled in the art will be able to choose the angle B according to the requirements.

[0044] In particular, the conducting body 62 of the second radiating element 60 is formed by a substantially flat rectangular or square plate.

[0045] In the example of the figure 1 , the conducting body 62 of the second radiating element 60 is square.

[0046] Advantageously, the conducting body 62 of the second radiating element 60 is made of a metallic material, for example copper.

[0047] The conducting body 62 of the second radiating element 60 has four vertices 64A, 64B, 64C, 64D connected by sides 66AB, 66BC, 66CD, 66DA.

[0048] At least one vertex 64A, 64C of the conducting body 62 of the second radiating element 60 has a chamfer 68.

[0049] Advantageously, the conducting body 62 of the second radiating element 60 comprises at least one vertex 64A, 64C having a chamfer 68, the vertices 64B, 64D other than the at least one vertex 64A, 64C having a chamfer 68 being curved.

[0050] Advantageously, at least one chamfer 68 is such that the second radiating element 60 is able to transform a circularly polarized wave received by the second radiating element 60 into a linearly polarized wave and to transform a linearly polarized wave to be emitted by the second radiating element 60 into a circularly polarized wave.

[0051] Even more advantageously, at least one chamfer 68 of the second radiating element 60 has a chamfer angle α2 defined with a side of the square or rectangle corresponding to the conducting body 62 between 30° and 120°.

[0052] In the specific example of the figure 1 The conducting body 62 of the second radiating element 60 comprises two opposite vertices 64A, 64C, each with a chamfer 68, the other vertices 64B, 64D being advantageously curved. For example, the chamfer angles α2 of the two opposite chamfered vertices 64A, 64C are different, substantially identical, or exactly identical.

[0053] Even more advantageously, in the specific example of the figure 1 , the chamfer 48 of the conducting body 42 of the first radiating element 40 is arranged opposite one or the other of the two chamfers 68 of the conducting body 62 of the second radiating element 60.

[0054] In the example of the figure 1 : the conducting body 42 of at least a first radiating element 40 comprises a single vertex 44A having a chamfer 48; the conducting body 62 of at least a second radiating element 60 comprises two opposite vertices 64A, 64C each having a chamfer 68.

[0055] These features allow for optimization of the circular polarization ellipticity ratio in dissociated frequency bands, both in transmit and receive modes. Specifically, the 48 chain brake can be used to adjust the polarization over one frequency band, and the 68 chamfers can be used to adjust the polarization over another frequency band. Alternatively, the 48 and 68 chamfers can be used to adjust the polarization over the same frequency band to improve the performance of the planar antenna 10.

[0056] Advantageously, the conducting body 62 of the second radiating element 60 further comprises at least one curved vertex 69.

[0057] For example, at least one curved vertex 68 of the conducting body 62 of the second radiating element 60 has a radius of curvature R2 between 0% and 50% of the length of a side 66 of the square or rectangle of the conducting body 62.

[0058] Thanks to the invention, better performance is achieved over a wide frequency band and linearly polarized waves are transformed into circularly polarized waves and vice versa by the radiating elements directly, without the need for a dedicated polarizer.

[0059] Furthermore, the chamfer angles α1, α2 and / or the radii of curvature R1, R2 and / or the angle β between the orientation directions D1, D2 of the radiating elements 40, 60 are specifically chosen to optimize the transmission / reception performance of the planar antenna 10 according to the parameters of the waves to be transmitted / received and to optimize polarization purity in the chosen band. These variable parameters provide numerous degrees of freedom for optimizing the antenna 10.

Claims

1. Planar antenna (10) comprising: - a support (20); - at least one first radiating element (40) mounted on the support (20) and comprising a conductive body (42) substantially rectangular or square planar; and - at least one layer of dielectric material (50) arranged on the at least one first radiating element (40); characterized in that the planar antenna (10) further comprises at least one second radiating element (60) arranged on at least one layer of dielectric material (50) opposite at least one first radiating element (40) and comprising a substantially rectangular or square planar conducting body (62), each of the conducting body (42) of at least one first radiating element (40) and of the conducting body (62) of at least one second radiating element (60) comprising at least one vertex (44A, 64A, 64C) having a chamfer (48, 68).

2. Planar antenna (10) according to claim 1, wherein at least one chamfer (48, 68) is such that the corresponding radiating element (40, 60) is capable of transforming a circularly polarized wave received by said radiating element (40, 60) into a linearly polarized wave and of transforming a linearly polarized wave to be emitted by said radiating element (40, 60) into a circularly polarized wave.

3. Planar antenna (10) according to claim 1 or 2, wherein at least one chamfer (48, 68) has a chamfer angle (α1, α2) defined with a side (46, 66) of the corresponding square or rectangle between 30° and 120°.

4. Planar antenna (10) according to any one of the preceding claims, wherein each of the conducting body (42) of at least one first radiating element (40) and of the conducting body (62) of at least one second radiating element (60) comprises at least one curved vertex (49, 69).

5. Planar antenna (10) according to claim 4, wherein at least one curved vertex (49, 69) has a radius of curvature (R1, R2) between 0% and 50% of the length of a side (46, 66) of the square or rectangle of the corresponding conducting body (42, 62).

6. Planar antenna (10) according to claim 4 or 5, wherein for each of the conducting body (42) of at least one first radiating element (40) and of the conducting body (62) of at least one second radiating element (60): - the conducting body (42, 62) comprises at least one vertex (44A, 64A, 64C) having a chamfer (48, 68); - the vertices (44B, 44C, 44D, 64B, 64D) other than the at least one vertex (44A, 64A, 64C) having a chamfer (48, 68) are curved.

7. Planar antenna (10) according to any one of the preceding claims, wherein each radiating element (40, 60) has an orientation direction (D1, D2), the orientation direction (D1) of at least one first radiating element (40) and the orientation direction (D2) of at least one second radiating element (60) forming an angle (β) between 0° and 360°.

8. Planar antenna (10) according to any one of the preceding claims, in which: - the conducting body (42) of at least one first radiating element (40) comprises a single vertex (44A) having a chamfer (48); - the conducting body (62) of at least one second radiating element (60) comprises two opposite vertices (64A, 64C) each having a chamfer (68).

9. Planar antenna (10) according to claim 8, wherein the chamfer (48) of the conducting body (42) of at least one first radiating element (40) is arranged opposite one or the other of the two chamfers (68) of the conducting body (62) of at least one second radiating element (60).

10. Planar antenna (10) according to any one of the preceding claims, wherein each conductive body (42, 62) is made of a metallic material, for example copper, the dielectric material layer (50) being made of epoxy resin or a derivative of polytetrafluoroethylene.

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