FR3081619A1 - RADIANT ELEMENT, ANTENNA AND METHOD OF MANUFACTURING THE SAME - Google Patents

Abstract

The invention relates to a radiating element of an antenna (10) comprising: - at least one wired nanostructure (45), each wired nanostructure (45) extending in the same direction (D), called the common direction, between a first end (55) and a second end (60), and - an inductor (50) connected to each first end (55) of a nanostructure (45), the inductor (50) being made of a first conductive material, inductance (50) extending in a plane normal to the common direction (D).

Description

Radiating element, antenna and associated manufacturing method

The present invention relates to a radiating element. The present invention also relates to an antenna comprising such a radiating element and a method of manufacturing such a radiating element.

Many types of antennas exist, varying according to the intended applications, for example according to the wavelength and the power, or even the spectral characteristics of the desired emission. In particular, many types of antennas include a set of radiating elements, also called elementary antennas. The radiating elements make it possible, by controlling their arrangement, their conformation or the electrical signal which feeds each of them, to improve the gain of the antenna or to control its directivity or the shape of the beam emitted.

However, the existing antennas have relatively large dimensions, of the order of several centimeters to several tens of centimeters depending on the frequency and the power required by the intended application, and therefore a significant volume and weight. The large dimensions are inconvenient for certain applications, for example for mobile devices, since an increase in the volume and / or the weight of the devices results. In addition, devices containing large antennas are more difficult to transport. The integration of antennas into devices whose geometry is fixed for other functions than communication is also made difficult.

There is therefore a need for a radiating element having a smaller footprint than the radiating elements of the state of the art.

To this end, a radiating element of an antenna is proposed comprising:

• at least one wire nanostructure, each wire nanostructure extending in the same direction, called common direction, between a first end and a second end, and • an inductor connected to each first end of a nanostructure, the inductor being produced in a first conductive material, the inductance extending in a plane normal to the common direction.

According to particular embodiments, the radiating element comprises one or more of the following characteristics taken alone or in any technically possible combination:

- the radiating element has at least one of the following properties:

• the first conductive material is made of molybdenum, • each wire nanostructure is made of the same material, and • at least one wire nanostructure is a carbon nanotube.

- all of the wired nanostructures form a bundle of wired nanostructures having an aspect ratio of between 5 and 15.

the radiating element comprises at least ten wire nanostructures, each wire nanostructure having a dimension along the common direction, the dimensions varying between 50% and 150% of the median value of the dimensions, the median value being greater than or equal to 500 micrometers.

- the inductor (50) has a spiral shape.

An antenna is also proposed comprising:

• a first radiating element as defined above, and • for each radiating element, a transmission line comprising a zone made of a second conductive material and two ground planes, the transmission line extending in the same plane as the inductance and the zone being connected to the inductance, the first material being in particular the same material as the second material, each ground plane being made of a third conductive material, the zone being arranged between the two ground planes.

According to particular embodiments, the antenna comprises one or more of the following characteristics taken alone or in any technically possible combination:

- the inductance is, moreover, at least partially interposed between the two ground planes.

the antenna comprises at least a second radiating element as defined above, the first radiating element and the second radiating element having inductance values different from each other.

A method of manufacturing a radiating element of an antenna is also proposed, comprising steps of:

• supply of a planar substrate, • deposition, on the substrate, of a planar layer, the planar layer being made of a first conductive material, • etching of the planar layer to form an inductance, and • growth, on the inductance, of a set of wire nanostructures, each wire nanostructure extending in the same direction, called common direction, between a first end and a second end, the inductance extending in a plane normal to the common direction.

According to a particular embodiment, the deposition step is carried out by sputtering, the first material being molybdenum, the method comprising, prior to the growth step, a step of deposition on the inductance of a catalyst for the growth of wire nanostructures.

Characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of nonlimiting example, and made with reference to the appended drawings, in which:

FIG. 1 is a diagram of an antenna comprising a set of radiating elements and a set of transmission lines,

FIG. 2 is a sectional view of a radiating element and of a transmission line in FIG. 1, the radiating element comprising a bundle of nanostructures,

- Figure 3 is a top view of a bundle of nanostructures,

FIG. 4 is a top view of the radiating element and of the transmission line of FIG. 2, and

- Figure 5 is a flow chart of the steps in a method of manufacturing a radiating element.

An antenna 10 is shown in FIG. 1.

The antenna 10 is configured to transmit and / or receive a set of electromagnetic waves. For example, the antenna 10 is configured to transmit and receive a set of electromagnetic waves.

The electromagnetic wave has a frequency between 3 kilohertz (KHz) and 300 gigahertz (GHz). It should be noted that the frequency of the electromagnetic wave is likely to vary depending on the applications envisaged for the antenna 10.

The antenna 10 comprises a substrate 15, radiating elements 20 and transmission lines 25.

According to the example in FIG. 1, the antenna 10 includes a transmission line 25 for each radiating element 20.

As a variant, the antenna 10 comprises a single radiating element 20 and a single transmission line 25.

The antenna 10 further comprises an electrical ground such as a metal chassis. Alternatively, the electrical ground is an electrical circuit connected to earth.

The substrate 15 is provided to support the radiating elements 20 and the transmission lines 25.

The substrate 15 has a support face 30.

The support face 30 is flat.

A normal direction Z is defined as being the direction perpendicular to the support face 30.

The substrate 15 comprises a support plate 35 and a buffer layer 40.

The support plate 35 is configured to serve as a support for the buffer layer 40, the radiating elements 20 and the transmission lines 25.

The support plate 35 is, for example, made of silicon. According to a variant, the support plate 35 is made of alumina.

The support plate 35 has, for example, a thickness of between 200 micrometers (pm) and 500 pm.

The support plate 35 is made of a material having an electrical resistivity. The electrical resistivity is, for example, greater than or equal to 10,000 Ohm. Centimeter. Such electrical resistivity makes it possible to limit the radiofrequency losses in the support plate 35.

It should be noted that a material other than silicon may be used to make the support plate 35.

The buffer layer 40 is interposed between, on the one hand, the support plate 35 and, on the other hand, the radiating elements 20 and the transmission lines 25.

The buffer layer 40 is delimited in the normal direction Z by the support plate 35 and by the support face 30.

The buffer layer 40 is made of an electrically insulating material. The buffer layer 40 is, for example, made of silicon oxide.

The buffer layer 40 has a thickness, in the normal direction Z, of between 500 nanometers and 5 micrometers. For example, the thickness of the buffer layer 40 is equal to 2 micrometers.

A sectional view of a radiating element 20 in a plane parallel to the normal direction Z is shown in FIG. 2.

Each radiating element 20 is configured to transmit and / or receive an electromagnetic wave.

Each radiating element 20 comprises a beam F of nanostructures 45 and an inductance 50.

The beam F comprises at least ten nanostructures 45.

As a variant, the radiating element 20 comprises a single nanostructure 45.

The term “nanostructure” is understood to mean a structure having at least one nanometric dimension.

One dimension of an object, measured in one direction, is the distance between the two points of the object furthest from each other in said direction. A nanometric dimension is a dimension strictly less than 1 micrometer, preferably strictly less than 100 nanometers.

A direction D is defined for each nanostructure 45. This means that each nanostructure 45 extends in the direction D defined for the nanostructure 45 considered.

The direction D of each nanostructure 45 is parallel to the normal direction Z.

Each nanostructure 45 has a first end 55 and a second end 60. Each nanostructure 45 extends between the first end 55 and the second end 60.

The direction D is, for example, parallel to the normal direction Z.

Direction D is common to all the nanostructures 45 of the same radiating element 20.

A diameter measured in a plane perpendicular to the direction D is defined for each nanostructure 45,

The diameter of each nanostructure 45 is between 20 nanometers (nm) and 100 nm.

The length of each nanostructure 45 is between 300 μm and 1 millimeter (mm). In particular, the length of each nanostructure 45 is greater than or equal to 500 μm.

The length of each nanostructure 45 is measured in the common direction D.

Each nanostructure 45 is a wired nanostructure.

A wire structure is a structure having a length strictly greater than 10 times the diameter. The relationship between, in the numerator, the length and, in the denominator, the diameter, is called "aspect ratio".

Advantageously, each nanostructure 45 is such that the aspect ratio is strictly greater than 20.

Nanotubes are examples of wire nanostructures 45. Nanotubes are hollow wire structures having a diameter of less than 100 nanometers. In other words, a nanotube is a hollow wire nanostructure.

The term “beam” is understood to mean a set of nanostructures 45 in which the nanostructures 45 are distant from each other by a distance less than or equal to the length of the nanostructures 45. The distance between the nanostructures 45 is measured in a plane perpendicular to the common direction D.

According to special cases, the distance is less than or equal to half the length, for example less than or equal to one fifth of the length, in particular less than or equal to one tenth of the length.

According to one embodiment, a median value is defined for the length of the nanostructures 45 of the same beam F. The median value is a value such that half of the nanostructures 45 of the beam F considered have a length greater than or equal to the value median, the other half having a length less than or equal to the median value.

The lengths of the nanostructures 45 of the beam considered vary between 50 percent (%) and 150% of the median value.

The median value is, for example, greater than or equal to five hundred micrometers.

A total length is defined for the beam F. The total length is, for example, defined as being the length of the longest nanostructure 45 among the set of nanostructures 45 belonging to the beam F.

The total length is, for example, identical for each beam F.

According to one embodiment, the total lengths of at least two beams F are different from each other.

The beam has an envelope common to all nanostructures. The term “envelope” is understood to mean a surface enveloping the nanostructures 45 and tangent to the nanostructures 45 which delimit the beam F in a plane perpendicular to the common direction D.

A maximum lateral dimension is defined for the envelope. The maximum lateral dimension is the largest dimension of the envelope in a plane perpendicular to the common direction D. The maximum lateral dimension is between 20pm and 1mm.

An aspect ratio equal to the ratio between, in the numerator, the total length of the beam F and, in the denominator, the maximum lateral dimension, is defined for the beam F.

The aspect ratio of the beam F is, for example, between 5 and 15. According to one embodiment, the aspect ratio of the beam F is between 9 and 10.

The beam F is shown seen in the common direction D in FIG. 3.

The envelope has a cross section to the common direction D of circular shape.

It should be noted that forms other than the circular shape can be envisaged for the section of the beam F. For example, the section of the beam F has a circular shape, or even a polygonal shape such as a rectangular or cross shape.

The nanostructures 45 are all made of the same material.

In particular, each nanostructure 45 is a carbon nanotube.

In Figure 3, each nanostructure 45 is a double-sheet carbon nanotube. It should be noted that the carbon nanotubes are likely to be single-sheet carbon nanotubes, multi-sheet carbon nanotubes or even a mixture of single-sheet carbon nanotubes and multi-sheet carbon nanotubes.

It should be noted that other types of wired nanostructures 45 are capable of being used in place of carbon nanotubes.

For example, the nanostructures 45 are nanowires, for example nanowires of silicon or another semiconductor material.

According to another variant, the nanostructures 45 are made of an electrically conductive material such as a metallic material.

The inductor 50 of each radiating element 20 extends in a plane normal to the common direction D. Each inductor 50 is, for example, produced in the form of a conductive layer carried by the substrate 15. For example, each inductor 50 is perpendicular to the normal direction Z and the common direction D.

In particular, the inductor 50 is carried by the buffer layer 40.

The inductor 50 is made of a first conductive material. The first conductive material is, for example, a metallic material.

According to one embodiment, the first conductive material is molybdenum.

It should be noted that other conductive materials are likely to be envisaged for the inductor 50.

Each inductor 50 has a thickness measured in the normal direction Z. The thickness of the inductor 50 is between 100 nanometers and 1 micrometer. For example, the thickness of the inductor 50 is equal to 600 nanometers.

Each inductor 50 has an inductance value of, for example, between 1 nanoHenry and 10 nanoHenrys. According to one embodiment, the inductance value is equal to 5 nanoHenrys.

The inductance value is, for example, identical for the inductance 50 of each radiating element 20.

According to one embodiment, at least two inductors 50 among the set of inductors 50 grouping together the inductors 50 of each radiating element 45 have inductance values different from each other.

According to the example of FIG. 4, each inductor 50 has a first portion 65 and a second portion 70.

The first portion 65 extends in a plane perpendicular to the normal direction Z.

The first portion 65 is interposed between the beam F of nanostructures 45 and the substrate 15. The first portion 65 is connected to the first end 55 of each nanostructure 45.

The first portion 65 has a triangular shape in a plane normal to the common direction D.

It should be noted that other shapes than the triangular shapes can be envisaged for the first portion 65. For example, the first portion 65 has a circular or square shape.

The second portion 70 extends in a plane perpendicular to the normal direction Z.

A maximum dimension is defined for the second portion 70. The maximum dimension is measured in a plane perpendicular to the normal direction Z between the two points of the second portion 70 which are the most distant from each other.

The maximum dimension 70 is between 100 μm and 1 mm. For example, the maximum dimension 70 is between 200 μm and 500 μm.

It should be noted that the maximum dimension 70 is likely to vary.

The second portion 70 has a spiral shape in a plane perpendicular to the normal direction Z.

The second portion 70 surrounds the first portion 65 in a plane perpendicular to the normal direction Z.

According to one embodiment, the second portion 70 is formed by a succession of straight segments. For example, each line segment is perpendicular to the line segments to which it is contiguous.

As a variant, a curved part of the second portion 70 is interposed between two contiguous straight line segments.

According to another variant, the second portion 70 is formed by a single curve wound on itself.

It should be noted that a second portion 70 having a different shape from a spiral is also possible.

The second portion 70 has a third end 75 and a fourth end 80. The second portion 70 extends in a spiral from the third end 75 to the fourth end 80.

The third end 75 is the end of the second portion 70 which is located on the periphery of the second portion 70 in a plane perpendicular to the normal direction Z.

The fourth end 80 is the end of the second portion 70 which is located on the periphery of the first portion 65 in a plane perpendicular to the normal direction Z. The fourth end 80 is therefore surrounded by the rest of the second portion 70 in a plane perpendicular to the normal direction Z.

The fourth end 80 is connected to the first portion 65.

The transmission line 25 extends in the same plane as the inductor 50. In particular, the transmission line 25 is produced in the form of a layer carried by the substrate 15.

The transmission line 25 comprises a conductive zone 85 and at least one ground plane 90. In particular, the transmission line 25 shown in FIG. 4 comprises two ground planes 90.

The conductive area 85 is connected to the inductor 50. For example, the conductive area 85 is connected to the third end 75 of the inductor 50.

The conductive zone 85 is configured to receive an electric current from the inductor 50. Such a current is notably generated by the inductor 50 following the reception of an electromagnetic wave.

The conductive zone 85 is further configured to receive an electric current from an electric source external to the antenna 10 and to supply the inductor 50 with said electric current.

The conductive area 85 has, for example, a rectangular shape.

The conductive area 85 has a thickness measured in the normal direction Z. The thickness of the conductive area 85 is between 100 nanometers and 1 micrometer. For example, the thickness of the conductive area 85 is equal to 600 nanometers.

The conductive area 85 is made of a second conductive material.

The second conductive material is, for example, a metallic material.

According to one embodiment, the second conductive material is the same material as the first conductive material. For example, the second conductive material is molybdenum.

It should be noted that other conductive materials can be envisaged for the conductive zone 85.

Each ground plane 90 is connected to the ground of the antenna 10.

¹⁰

Each ground plane 90 has a thickness measured in the normal direction Z. The thickness of each ground plane 90 is between 100 nanometers and 1 micrometer.

For example, the thickness of each ground plane 90 is equal to 600 nanometers.

Each ground plane 90 is made of a third conductive material.

The third conductive material is, for example, a metallic material.

According to one embodiment, the third conductive material is the same material as the first conductive material. For example, the third conductive material is molybdenum.

It should be noted that other conductive materials can be envisaged for each ground plane 90.

According to one embodiment, the conductive area 85 is arranged between the two ground planes 90.

A distance, in a plane perpendicular to the normal direction Z, between the conductive area 85 and the ground plane 90 closest to the conductive area 85 is between 50 μm and 250 μm.

According to the example proposed, the conductive area 85 is equidistant from the two ground planes 90.

In the example shown in FIG. 4, the inductor 50 is at least partially interposed between the two ground planes 90.

A distance between the inductor 50 and the ground plane (s) 90 is between 20 pm and 300 pm.

According to one embodiment, each ground plane 90 has an "L" shape. Each ground plane 90 then has a first branch and a second branch, the two branches being perpendicular to each other.

The first branch of each ground plane 90 extends in the direction of the other ground plane 90 belonging to the same transmission line 25. For example, the first two branches of the same transmission line 25 are aligned the one with the other.

The conductive area 85 of each transmission line 25 is, for example, interposed between the first two branches to the transmission line 25 considered.

The first two branches of the same transmission line 25 are, for example, interposed between the two corresponding second branches.

Each inductor 50 is, for example, interposed between the two second branches of the ground planes 90 between which the inductor 50 is interposed. For example, the inductor 50 is housed in a rectangular area delimited on a first side of the rectangular area by the first two branches, on a second side of the rectangular area by one of the second branches and on a third side of the rectangular area by the other second branch, the first side being perpendicular to the second side and to the third side.

The operation of the antenna 10 will now be described.

In transmission, at least one transmission line 25 receives a first electric current. In particular, the first electric current is transmitted, from a device external to the antenna 10, to the conductive zone 85.

The conductive zone 85 transmits the first electric current to the inductance 50 of the radiating element 20 connected to the transmission line 25 considered.

In response to reception of the first electric current by the inductor 50, a first electromagnetic wave is emitted by the radiating element 20.

On reception, a second electromagnetic wave is received by at least one radiating element 20.

Following the reception of the second electromagnetic wave, a second electric current appears in the inductance 50 of the radiating element 20 considered. The second electric current is transmitted by the inductor 50 to the conductive area 85 connected to the inductor 50.

The second electric current is then transmitted, by the transmission line 25 considered, to a device external to the antenna 10.

The radiating element 20 has very small dimensions. In particular, the dimensions of the radiating element 20 are smaller than the dimensions of the radiating elements of the state of the art. The antenna 10 therefore has a lower volume and weight than the antennas of the prior art.

In particular, the combination of the nanostructure (s) 45 and the inductance 50 makes it possible to minimize the length of the nanostructures 45 relative to a radiating element 20 not comprising an inductance 50.

An aspect ratio, for the beam F, of between 5 and 15 typically has good mechanical strength while allowing good efficiency of conversion of the electric current into the electromagnetic wave and vice versa. An aspect ratio of between 9 and 10 is an example of an aspect ratio which is particularly advantageous for obtaining good mechanical strength and good conversion efficiency.

In addition, the length of the nanostructures 45 and the inductance value, which varies as a function of the dimensions of the inductance 50, make it possible to easily adapt the radiating element 20 to different frequency values. In particular, antennas 10 having a wide transmit eVou receive band are obtained when different total lengths or inductance values are used for certain radiating elements 20.

Nanostructures 45 having a median length greater than or equal to 500 nanometers make it possible to obtain good conversion efficiency.

The spiral shape is a shape making it possible to obtain a particularly compact inductor 50, and therefore a radiating element 20 of particularly reduced dimensions.

The use of a buffer layer 40 made of an electrically insulating material makes it possible to limit the radiofrequency losses during the use of the radiating element 20.

An antenna 10 in which each inductor 50 is interposed at least partially between the two corresponding ground planes 90 is also particularly compact.

Such an antenna 10 is also easy to manufacture, as illustrated with reference to FIG. 5 which is a flow chart of a method for manufacturing a radiating element 20.

The manufacturing method comprises a step 100 of supply, a step 110 of deposition, a step 120 of etching, a step 130 of placement and a step 140 of growth.

During the supply step 100, the substrate 15 is supplied.

During the deposition step 110, a layer of the first conductive material is deposited on the substrate 15.

For example, when the first conductive material is molybdenum, the deposition step 110 comprises the deposition of the molybdenum layer by sputtering.

Sputtering (also known as sputtering) is a thin film deposition technique in which a target of material to be deposited is supplied, generally as a solid material, into a deposition chamber and a plasma is formed in a low pressure gas occupying the deposition chamber. The application of a potential difference between the target and the walls of the deposition chamber causes the target to be bombarded by electrically positively charged plasma species. The bombardment causes the target to be sprayed and thus the material to be deposited in the atom deposition chamber. The condensation of the atoms thus released on a substrate then forms a layer of the material to be deposited.

It should be noted that other deposition techniques can be envisaged, in particular if the first conductive material is not molybdenum.

During the etching step 120, the layer of the first conductive material is etched to form the inductor 50.

The etching step 120 includes, for example, a photolithography step and / or an ion beam etching step. Ion beam etching consists in projecting onto the layer to be etched a beam of ions, in particular of Argon ions, with high energy to machine the layer to be etched.

It should be noted that other techniques for etching the layer of first conductive material are possible.

During the placement step 130, a catalyst C for the growth of nanostructures 45 is deposited on the inductor 50.

Catalyst C is a metallic material. The most common C catalysts to grow nanotubes or nanowires are nickel, cobalt, iron and gold. For example, catalyst C is iron. Alternatively, catalyst C is made of an alloy of at least two metals.

Catalyst C is, for example, in the form of a set of nanoparticles.

The particles of catalyst C are nanoparticles. Preferably, each particle has three nanometric dimensions. For example, each dimension of each particle is strictly between 1 nanometer and 100 nanometers.

The particles of catalyst C are, for example, obtained by lithography. Lithography makes it possible to obtain a perfectly periodic network of particles of catalyst C.

As a variant, the particles are obtained by fragmentation and controlled dewetting of a layer of catalyst C deposited on the inductor 50.

According to another variant, the particles of catalyst C are obtained by spraying, on the inductor 50, a solution comprising these particles. As a variant, the particles are deposited by electrostatic grafting on the inductor 50.

The previous methods, different from lithography, make it possible to obtain a random network for which the average distance between particles is controlled.

The particles are, for example, liquid when the catalyst C is at the set temperature Te. This is for example the case of silicon nanowires whose growth is catalyzed using gold particles. As a variant, the particles are solid when the catalyst C is at the set temperature Te. This is the case, for example, with the growth of carbon nanotubes.

Alternatively, catalyst C forms a homogeneous layer.

During the placement step 130, the catalyst C is deposited so as to form a layer having, in a plane perpendicular to the normal direction Z, a shape identical to the shape of the section of the beam F.

It should be noted that, in certain cases, it is possible to use no catalyst.

This is for example the case for certain types of nanostructures. It is therefore possible to replace step 130 of placing a catalyst C with a step of depositing a layer preventing the growth of nanostructures elsewhere than on the inductor 50.

For example, this step of depositing a layer preventing growth includes an etching step during which an opening is formed at the level of the inductance 50 in the layer preventing growth in order to allow the growth of a beam F of nanostructures 45.

During the growth step 140, at least one nanostructure 45 is obtained. In particular, the nanostructures 45 grow on the inductance 50 to form a beam F.

According to one embodiment, a nanostructure 45 is obtained for each particle of catalyst C.

The nanostructures 45 are, for example, obtained by chemical vapor deposition. Chemical vapor deposition (commonly known by the acronym CVD from the Chemical Vapor Deposition) is a technique frequently used to deposit material on a substrate. Chemical vapor deposition takes place in a closed enclosure, delimiting a chamber isolated from the outside atmosphere and containing at least one substrate, generally maintained at a high temperature. A gas called "precursor" is injected into the enclosure and decomposes on contact with the heated substrate, releasing atoms of one or more predetermined elements on the substrate. The released atoms form chemical bonds between them leading to the formation, on the substrate, of the desired material.

The thermal chemical vapor deposition process, also known by the name "Thermal Chemical Vapor Deposition", is a technique in which the substrate 15 is heated to an elevated temperature of the order of 600 degrees Celsius or more is a type of CVD particularly suitable for the growth of carbon nanotubes.

According to one embodiment, during growth by chemical vapor deposition, a plasma is generated in the growth chamber.

Several radiating elements 20 are produced simultaneously. For example, during the etching step 120, the inductors 50 of several radiating elements are formed. During the placement step 130, a catalyst C is deposited on each inductance 50. During the growth step 140, at least one nanostructure 45 is formed on each inductance 50.

It should be noted that the manufacturing method is also capable of comprising the manufacture of each transmission line 25. For example, each transmission line 25 is formed, in the layer of first conductive material, during the etching step 120.

According to a variant, when the second conductive material is not identical to the first conductive material, the manufacturing process comprises a step of depositing a layer of second conductive material and a step of etching the layer of second conductive material to form transmission lines 25.

The method of manufacturing the radiating elements 10 is simple.

Molybdenum is a material that resists well the conditions prevailing in a growth frame of nanostructures 45, in particular a CVD frame. The inductance 50 and the transmission lines 25 are therefore not degraded during the growth of the nanostructures 45, in particular when the nanostructures 45 are carbon nanotubes.

Sputtering is a deposition method for obtaining good quality layers of molybdenum.

Claims (10)

16 CLAIMS 1Radiating element (20) of an antenna (10) comprising. - at least one wire nanostructure (45), each wire nanostructure (45) extending in the same direction (D), called common direction, between a first end (55) and a second end (60), and - an inductor (50) connected to each first end (55) of a nanostructure (45), the inductor (50) being made of a first conductive material, the inductor (50) extending in a plane normal to the common management (D). 2, - A radiating element according to claim 1, in which the radiating element (20) has at least one of the following properties: - the first conductive material is made of molybdenum, each wire nanostructure (45) is made of the same material, and - at least one wire nanostructure (45) is a carbon nanotube. 3, - A radiating element according to claim 1 or 2, wherein I together of the wired nanostructures (45) form a beam (F) of wired nanostructures (45) having an aspect ratio of between 5 and 15. 4, - A radiating element according to any one of claims 1 to 3, in which the radiating element (20) comprises at least ten wire nanostructures (45), each wire nanostructure (45) having a dimension along the common direction (D), the dimensions varying between 50% and 150% of the median value of the dimensions, the median value being greater than or equal to 500 micrometers. 5, - A radiating element according to any one of claims 1 to 4, wherein the inductor (50) has a spiral shape. 6, - Antenna (10) comprising: - a first radiating element (20) according to any one of claims 1 to 5, and - for each radiating element (20), a transmission line (25) comprising a zone (85) made of a second conductive material and two ground planes (90), the transmission line (25) extending in the same plane that the inductor (50) and the area (85) being connected to the inductor (50), the first material being in particular the same material as the second material, each ground plane (90) being made of a third material conductor, the area (85) being arranged between the two ground planes (90). 7. - Antenna according to claim 6, in which the inductor (50) is, moreover, interposed at least partially between the two ground planes (90). 8. - Antenna according to claim 6 or 7, comprising at least a second radiating element (20) according to any one of claims 1 to 5, the first radiating element (20) and the second radiating element (20) having values of inductances different from each other. 9. - Method for manufacturing a radiating element (20) of an antenna (10) comprising steps of: - supply of a flat substrate (15), - depositing, on the substrate (15), a planar layer, the planar layer being made of a first conductive material, - etching of the planar layer to form an inductance (50), and - Growth, on the inductance (50), of a set of wire nanostructures (45), each wire nanostructure (45) extending in the same direction, called common direction (D), between a first end (55) and a second end (60), the inductor (50) extending in a plane normal to the common direction (D). 10. - The manufacturing method according to claim 9, wherein the deposition step is carried out by sputtering, the first material being molybdenum, the method comprising, prior to the growth step, a deposition step on the inductance (50) of a catalyst for the growth of wire nanostructures (45).