Transmitting array antenna cell

Abstract

Transmitter network antenna cell The present description relates to a transmitter network antenna cell (105) comprising: – a semiconductor substrate (201); – a first polarizer (207a), located on the side of a first face (201a) of the semiconductor substrate; – a second polarizer (207b), located on the side of a second face (201b) of the semiconductor substrate opposite the first face; and – at least one radiating element (203-1, 203-2) interposed between the second face (201b) of the semiconductor substrate and the second polarizer (207b), said at least one radiating element being adapted to switch between at least two phase states. Abbreviation figure: Fig. 2

Description

Title of the invention: Antenna cell with transmitting array Technical field

[0001] The present description relates generally to electronic devices. The present description relates in particular to radio antennas, more precisely to transmit array antennas. Prior art

[0002] In various applications, such as satellite communication systems and communication devices on 5G and 6G mobile networks, it would be desirable to have electronically steerable radio antennas. For example, a scanning range of at least 120° is often required for an antenna integrated in a mobile satellite communication terminal to ensure efficient communication between the terminal and the satellite. Similar specifications will be required for antennas in a 6G type access point at sub-THz frequencies, i.e. frequencies from 100 to 500 GHz.

[0003] Among the various radio antenna technologies capable of meeting the needs of applications using sub-THz frequencies, phased array antennas and reconfigurable liquid crystal-based metasurfaces have been proposed in particular. Phased array antennas have the advantage of allowing precise control of the orientation of the beam emitted by the antenna and of providing access to a wide angular range. Reconfigurable liquid crystal-based metasurfaces have a greater compactness than phased array antennas, while offering similar advantages. However, phased array antennas have power consumption and production costs that are too high for integration into consumer devices, and reconfigurable metasurfaces suffer from excessive losses and a relatively low bandwidth.

[0004] Transmitting array antennas and reflecting array antennas have also been proposed. Transmitting array antennas typically comprise several elementary cells each comprising a first antenna element irradiated by an electromagnetic field emitted by one or more focal sources, a second antenna element transmitting a modified signal to the outside of the antenna, and a coupling element interposed between the first and second antenna elements. Reflecting array antennas typically comprise several elementary cells each comprising an antenna element irradiated by an electromagnetic field emitted by one or more sources, a reflecting element, for example a plane of ground, reflecting a modified signal towards the outside of the antenna and a coupling element between the antenna element and the reflector element. Transmitting array or reflector array antennas are for example made on a CMOS (Complementary Metal-Oxide-Semiconductor) type substrate. Furthermore, each elementary cell of a reconfigurable transmitting or reflector array antenna comprises for example at least one switch, for example a switch based on a phase change material. Transmitting or reflector array antennas have the advantage of having, compared to phased array antennas and reconfigurable metasurfaces, better efficiency and lower production costs.However, existing transmitting or reflecting array antennas suffer from various drawbacks, such as high transmission losses, too narrow transmission and / or reception bands, significant production complexity, etc. Summary of the invention

[0005] There is a need to overcome all or part of the disadvantages of existing transmitting array antennas. In particular, it would be desirable to have transmitting array antennas having high gain, high energy efficiency and reduced complexity.

[0006] For this, one embodiment provides a transmitter array antenna cell comprising: - a semiconductor substrate; - a first polarizer, located on the side of a first face of the semiconductor substrate; - a second polarizer, located on the side of a second face of the semiconductor substrate opposite the first face; and - at least one radiating element interposed between the second face of the semiconductor substrate and the second polarizer, said at least one radiating element being adapted to switch between at least two phase states.

[0007] According to one embodiment, each radiating element comprises at least two parts connected by a switch formed in the semiconductor substrate.

[0008] According to one embodiment, said at least one radiating element comprises exactly first and second parts each having, in top view, a T shape.

[0009] According to one embodiment, the cell comprises exactly first and second radiating elements forming, in top view, a cross of which a first branch comprises the first and second parts of the first radiating element, and of which a second branch, substantially orthogonal to the first branch, comprises the first and second parts of the second radiating element.

[0010] According to one embodiment, the upper bar of the T formed by each part of each radiating element has an adjustable length.

[0011] According to one embodiment, each radiating element is located on and in contact with the second face of the semiconductor substrate.

[0012] According to one embodiment: - the first polarizer comprises a plurality of first conductive strips substantially parallel to each other; and - the second polarizer comprises a plurality of second conductive strips substantially parallel to each other and substantially orthogonal to the first conductive strips.

[0013] According to one embodiment, the cell further comprises: - a first insulating region interposed between the first face of the semiconductor substrate and the first polarizer; and - a second insulating region interposed between the second face of the semiconductor substrate and the second polarizer.

[0014] According to one embodiment, the first and second insulating regions are part of insulating layers of a printed circuit board, each radiating element and the first and second polarizers being formed in metallization levels of the printed circuit board.

[0015] According to one embodiment, the radiating element(s) are formed in at least one metallization level of an interconnection stack interposed between the semiconductor substrate and the second polarizer.

[0016] One embodiment provides a transmitter network comprising a plurality of cells as described.

[0017] According to one embodiment, the semiconductor substrate is common to several cells of the network.

[0018] One embodiment provides an antenna comprising a transmitting array as described and at least one source configured to irradiate one face of the array. Brief description of the drawings

[0019] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0020] [Fig.l] is a schematic and partial side view of an example of a transmitting array antenna of the type to which, by way of example, the described embodiments apply;

[0021] [Fig.2] is a schematic and partial side and sectional view of a cell of transmitting array antenna according to one embodiment;

[0022] [Fig.3A], [Fig.3B] and [Fig.3C] are schematic and partial top views of the cell of [Fig.2];

[0023] [Fig.4] is a schematic and partial top view of a variant of a radiating element of the cell of [Fig.2]; and

[0024] [Fig. 5] is a schematic and partial side and sectional view of a transmitting network of a radio antenna according to one embodiment. Description of the embodiments

[0025] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0026] For the sake of clarity, only the steps and elements useful for understanding the embodiments described have been shown and are detailed. In particular, embodiments of a transmitting array antenna cell are described below. The structure and operation of the primary source(s) of the antenna, intended to irradiate the transmitting array, will however not be detailed, the embodiments described being compatible with all or most of the known primary irradiation sources for transmitting array antennas. By way of example, each primary source is adapted to produce a beam of generally conical shape irradiating all or part of the transmitting array. Each primary source comprises for example a horn antenna. By way of example, the central axis of each primary source is substantially orthogonal to the mean plane of the array.

[0027] Furthermore, the manufacturing methods of the described transmitter networks will not be detailed, the production of the described structures being within the reach of the person skilled in the art from the indications of the present description, for example by implementing standard techniques for manufacturing printed circuits.

[0028] Unless otherwise specified, when referring to two elements connected to each other, this means directly connected without intermediate elements other than conductors, and when referring to two elements connected (in English "coupled") to each other, this means that these two elements can be connected or be connected by means of one or more other elements.

[0029] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made, unless otherwise specified, to the orientation of the figures.

[0030] Unless otherwise specified, the expressions “about”, “approximately”, “substantially”, and “of the order of” mean to within 10%, preferably to within 5%.

[0031] In the following description, the terms “insulator” and “conductor” mean respectively, unless otherwise specified, electrically insulating and electrically conductive.

[0032] [Fig.l] is a schematic and partial side view of an example of a transmitting array antenna 100 of the type to which, by way of example, described embodiments apply.

[0033] The antenna 100 typically comprises one or more primary sources 101 (a single source 101, in the example shown) irradiating a transmitting network 103. The source 101 may have any polarization, for example linear or circular. The network 103 comprises a plurality of elementary cells 105, for example arranged in a matrix according to rows and columns. Each cell 105 typically comprises a first antenna element 105a, located on the side of a first face of the network 103 arranged opposite the primary source 101, and a second antenna element 105b, located on the side of a second face of the network opposite the first face. The second face of the network 103 is for example turned towards an emission medium of the antenna 100.

[0034] Each cell 105 is capable, in transmission, of receiving electromagnetic radiation on its first antenna element 105a and of re-emitting this radiation from its second antenna element 105b, for example by introducing a known phase shift ¢). In reception, each cell 105 is capable of receiving electromagnetic radiation on its second antenna element 105b and of re-emitting this radiation from its first antenna element 105a with the same phase shift ¢.

[0035] The characteristics of the beam produced by the antenna 100, in particular its shape (or template) and its maximum emission direction (or pointing direction), depend on the values ​​of the phase shifts respectively introduced by the different cells 105 of the network 103. An amplitude control can also be exercised, by each elementary cell, on the incident electromagnetic wave.

[0036] Transmitting array antennas have the advantage, among other things, of being energy efficient and relatively simple, inexpensive and compact. This is due in particular to the fact that the transmitting arrays can be produced using planar technology, generally on a printed circuit.

[0037] The present description relates more particularly to antennas with a reconfigurable transmitter network 103. The transmitter network 103 is said to be reconfigurable when the elementary cells 105 are electronically controllable, individually, to modify their phase shift value ¢. This makes it possible to dynamically modify the characteristics of the beam generated by the antenna, and in particular to modify its pointing direction without mechanically moving the antenna or part of the antenna by means of a motorized element.

[0038] [Fig. 2] is a schematic and partial side and sectional view of an antenna cell with a transmitter array according to one embodiment, for example one of the elementary cells 105 of the transmitter array 103 of the antenna 100 described above in relation to [Fig. 1].

[0039] In the example shown, the elementary cell 105 comprises a semiconductor substrate 201. The substrate 201 is for example a wafer or a piece of wafer made of a semiconductor material, for example silicon. The semiconductor substrate 201 is for example of the CMOS (Complementary Metal-Oxide-Semiconductor) type. In this case, the substrate 201 comprises for example one or more electronic components produced in CMOS technology, for example at least one MOS (Metal-Oxide-Semiconductor) transistor. As a variant, the substrate 201 may be made of a semiconductor material other than silicon, for example an IILV semiconductor material such as gallium nitride (GaN) or gallium arsenide (GaAs).

[0040] In the example illustrated, the elementary cell 105 further comprises radiating elements 203-1 and 203-2 located on the semiconductor substrate 201. In this example, the radiating elements 203-1 and 203-2 are more precisely formed in an interconnection stack or network 204 located on and in contact with a face 201b of the substrate 201 (the upper face of the substrate 201, in the orientation of [Fig. 2]). In the example shown, the interconnection stack 204 comprises a stack of alternating conductive layers and insulating layers. By way of example, the insulating layers are made of silicon oxide (SiO2), and have for example a thickness of the order of 4 μm. The conductive layers of the interconnect stack 204, symbolized by hatched rectangles in [Fig.2], are for example metallic layers, also called metallization levels.Although not detailed in the drawings, the interconnect stack 204 comprises, for example, in addition to the radiating elements 203-1 and 203-2, conductive tracks formed in the conductive layers and conductive vias, for example metal vias, interconnecting conductive tracks located in different conductive layers.

[0041] The radiating elements 203-1 and 203-2 are formed in at least one of the conductive layers of the interconnect stack 204. In the illustrated example, the radiating elements 203-1 and 203-2 are formed in a single metallization level, for example in the upper metallization level, also called last metallization level, that is to say the metallization level furthest from the semiconductor substrate 201. This example is however not limiting and the radiating elements 203-1 and 203-2 may, as a variant, be formed in a metallization level other than the last metallization level and / or in several metallization levels of the stack 204. Furthermore, in the example shown, the upper metallization level is coated with an insulating layer of the stack 204. This example is however not limiting, the upper metallization level may, as a variant, be flush with the upper face of the stack 204.

[0042] The radiating elements 203-1 and 203-2 are for example of the “on-chip antenna” type. The geometry of the radiating elements 203-1 and 203-2 will be described in more detail below.

[0043] In the example illustrated, the elementary cell 105 further comprises insulating regions 205a and 205b located on either side of the semiconductor substrate 201. In this example, the insulating region 205a covers a face 201a of the semiconductor substrate 201 (the lower face of the substrate 201, in the orientation of [Fig. 2]) opposite the face 201b. The insulating region 205a is for example more precisely located on and in contact with the face 201a of the substrate 201.

[0044] In the example shown, the insulating region 205b is located on the substrate 201 and the radiating elements 203-1 and 203-2. In this example, the insulating region 205b is more precisely located on and in contact with the upper face of the interconnection stack 204. In the example illustrated where the last metallization level is coated with an insulating layer, the insulating region 205b is located on and in contact with this insulating layer. In the case where the last metallization level is flush with the upper face of the interconnection stack 204, the insulating region 205b is located on and in contact with the last metallization level of the stack 204.

[0045] By way of example, the substrate 201 and the interconnect stack 204 form an integrated circuit chip, for example more precisely a CMOS type integrated circuit chip.

[0046] The insulating regions 205a and 205b are for example each made of a material having a relative dielectric permittivity er, also called “dielectric constant”, of between 2 and 4. The insulating regions 205a and 205b are for example formed in one or more insulating layers of a printed circuit board. As a variant, each insulating region 205a, 205b may be made of quartz, fused silica, etc. For example, each insulating region 205a, 205b has a thickness of between 100 and 300 μm.

[0047] In the example illustrated, the elementary cell 105 further comprises polarizer type structures 207a and 207b located on either side of the semiconductor substrate 201. In this example, the polarizer 207a is located on the side of the face 201a of the substrate. semiconductor 201. In the example shown, the polarizer 207a covers a face of the insulating region 205a opposite the semiconductor substrate 201 (the lower face of the insulating region 205a, in the orientation of [Fig.2]).

[0048] In the example shown, the polarizer 207b is located on the side of the face 201b of the semiconductor substrate 201. In this example, the polarizer 207b covers a face of the insulating region 205b opposite the semiconductor substrate 201 (the upper face of the insulating region 205b, in the orientation of [Fig.2]).

[0049] By way of example, the polarizers 207a and 207b are respectively part of the first and second antenna elements 105a and 105b of the elementary cell 105. This corresponds for example to a case where the polarizer 207a is arranged opposite the primary source 101 and where the polarizer 207b is turned towards the external medium, or emission medium, of the antenna 100. As a variant, the polarizers 207a and 207b may respectively be part of the second and first antenna elements 105b and 105a of the elementary cell 105. This corresponds for example to a case where the polarizer 207a is turned towards the external medium, or emission medium, of the antenna 100 and where the polarizer 207b is arranged opposite the primary source 101. In any event, the polarizer located on the source side is polarized in the same direction as the source.In practice, we fix the polarization of the wave to be transmitted or received and we turn the polarizers so as to respect this constraint.

[0050] In the case where the insulating regions 205a and 205b are formed in one or more insulating layers of a printed circuit board, the radiating elements 203-1 and 203-2 and the polarizers 205a and 205b are for example formed in metallic conductive layers, also called metallization levels, of the printed circuit board.

[0051] As will be explained in more detail later, the elementary cell 105 is for example a reconfigurable cell adapted to switch between at least two phase states. In this case, each radiating element 203-1, 203-2 is for example connected to at least one switch formed in the semiconductor substrate 201, for example in a region 209 of the substrate 201 symbolized, in [Fig.2], by a dotted rectangle. The switch(es) formed in the region 209 are for example connected to the radiating elements 203-1 and 203-2 by conductive vias and / or conductive tracks of the interconnection stack 204. These connections have not been detailed in [Fig.2] so as not to overload the drawing.

[0052] [Fig.3A], [Fig.3B] and [Fig.3C] are schematic and partial top views of the elementary cell 105. [Fig.2] corresponds to a sectional view of the elementary cell 105 along the plane BB of FIGS. 3A to 3C.

[0053] [Fig.3A] illustrates more precisely an example of the structure of the polarizer 207a arranged on the side of the face 201a of the semiconductor substrate 201.

[0054] In the example shown, the polarizer 207a comprises a plurality of disjointed strips 301 located under and in contact with the insulating region 205a symbolized, in [Fig.3A], by a dotted square. In this example, the strips 301 are substantially parallel to each other. In the example illustrated, the strips 301 are spaced in a substantially regular manner, at a constant pitch. The strips 301 are for example made of a conductive material, for example a metal such as copper, or a metal alloy.

[0055] When the antenna 100 operates in transmission, the polarizer 207a is, in this example, adapted to control the transmission, towards the radiating elements 203-1 and 203-2, of waves coming from the primary source 101. The polarizer 207a makes it possible more precisely to transmit, towards the radiating elements 203-1 and 203-2, incident waves having a polarization substantially identical to that of the polarizer 207a, that is to say a rectilinear polarization substantially orthogonal to the bands 301, and to reflect incident waves having a polarization different from that of the polarizer 207a, that is to say a rectilinear polarization parallel to the bands 301.

[0056] [Fig.3B] illustrates more precisely an example of the structure of the radiating elements 203-1 and 203-2 interposed between the face 201b of the semiconductor substrate 201 and the polarizer 207b.

[0057] In the example shown, the radiating elements 203-1 and 203-2 form a cross, a first branch of which comprises two parts 305-1 and 305-2 of the radiating element 203-1 and a second branch of which, substantially orthogonal to the first branch, comprises two parts 305-3 and 305-4 of the radiating element 203-2. In this example, the parts 305-1, 305-2, 305-3 and 305-4 of the radiating elements 203-1 and 203-2 are disjointed and each have a T shape. In the example shown, the parts 305-1, 305-2, 305-3 and 305-4 of the radiating elements 203-1 and 203-2 have substantially identical dimensions, apart from manufacturing variations.

[0058] In the example shown, the upper bars, or horizontal bars, of the Ts formed by the parts 305-1, 305-2, 305-3 and 305-4 of the radiating elements 203-1 and 203-2 each have a curved shape. The upper bars of the Ts are, in the example illustrated in [Fig.3B], arcs of a circle extending laterally, in top view, along the periphery of the same circle 307. In the example shown, the upper bars of the Ts are regularly distributed around the periphery of the circle 307, and each vertical bar of the T intersects the corresponding upper bar substantially in its middle. In the example shown, the cross and the circle 307 are concentric. In this example, the upper bars of the Ts are located on the outer side of the cross, and the lower ends of the vertical bars of the Ts are located on the side of the center of the circle 307.

[0059] The radiating elements 203-1 and 203-2 are for example made of a conductive material. For example, the radiating elements 203-1 and 203-2 are formed in a metal layer located on and in contact with the face 201b of the semiconductor substrate 201. The parts 305-1, 305-2, 305-3 and 305-4 of the radiating elements 203-1 and 203-2 are for example each made of a metal, for example copper, or a metal alloy.

[0060] In the example shown, the vertical bars of the Ts formed by the parts 305-1 and 305-2 of the radiating element 203-1 extend laterally, in top view, along a first diameter of the circle 307 forming an angle equal to approximately 45° relative to the strips 301 of the polarizer 207a. Similarly, the vertical bars of the Ts formed by the parts 305-3 and 305-4 of the radiating element 203-2 extend laterally, in top view, along a second diameter of the circle 307 substantially orthogonal to the first diameter and forming an angle equal to approximately 45° relative to the strips 301 of the polarizer 207a.

[0061] The parts 305-1, 305-2, 305-3 and 305-4 of the radiating elements 203-1 and 203-2 are for example connected, in pairs of opposite parts, by switches. In order not to overload the drawing, a single switch 309 connecting the parts 305-1 and 305-2 of the radiating element 203-1 has been symbolized in [Fig.3B]. In the example illustrated, the switch 309 connects the lower ends of the vertical bars of the Ts formed by the parts 305-1 and 305-2 of the radiating element 203-1. Similarly, another switch, for example similar or identical to the switch 309, connects the lower ends of the other parts 305-3 and 305-4 of the radiating element 203-2. The switches are for example formed in the semiconductor substrate 201, for example in the region 209 previously described in relation to [Fig. 2]. For example, the switch 309 is a MOS transistor, a varactor, a PIN diode (from the English “Positive Intrinsic Negative”), etc.Although this has not been detailed in [Fig.3B], the switch 309 has for example conduction electrodes connected respectively to the parts 305-1 and 305-2 of the radiating element 203-1 by conductive tracks formed in the metallization levels of the interconnection stack 204 and / or conductive vias extending vertically in the thickness of the interconnection stack 204.

[0062] The switch 309 connecting the parts 305-1 and 305-2 of the radiating element 203-1 and the switch connecting the parts 305-3 and 305-4 of the radiating element 203-2 are for example controlled in opposition, one of the switches being controlled to the closed state when the other switch is controlled to the open state. Thus, the radiating element 203-1 is activated when the radiating element 203-2 is deactivated, and vice versa. This allows for example the elementary cell 105 to switch between two phase states, for example the 0° and 180° states in the case of the structure described in relation to figures 3A to 3C. The elementary cell 105 behaves, in this case, like a polarization converter.

[0063] Although [Fig.3B] illustrates an example in which the elementary cell 105 comprises two radiating elements 203-1 and 203-2, this example is not limiting and the elementary cell may, as a variant, comprise a number of radiating elements other than two, for example a single radiating element of generally circular shape comprising several portions of an arc of a circle connected to each other by one or more switches. Generally, each radiating element of the elementary cell 105 comprises for example at least one pair of diametrically opposed parts connected by a switch.

[0064] Furthermore, although [Fig.3B] illustrates a case in which the radiating elements 203-1 and 203-2 are produced in the same metallization level of the interconnection stack 204, this example is not limiting, one of the radiating elements 203-1, 203-2 being able, as a variant, to be formed in a metallization level different from that in which the other radiating element is formed. By way of example, the parts 305-1 and 305-2 of the radiating element 203-1 are produced in a first metallization level of the stack 204, for example the upper metallization level, and the parts 305-3 and 305-4 of the radiating element 203-2 are produced in a second metallization level separated from the first metallization level by one of the insulating layers of the stack 204, for example a lower metallization level interposed between the substrate 201 and the last metallization level.

[0065] [Fig.3C] illustrates in particular an example of the structure of the polarizer 207b arranged on the side of the face 201b of the semiconductor substrate 201.

[0066] In the example shown, the polarizer 207b comprises a plurality of strips 311 located on and in contact with the insulating region 205b. In this example, the strips 311 are substantially parallel to each other. The strips 311 are for example substantially orthogonal to the strips 301 of the polarizer 207a. In the example illustrated, the strips 311 are spaced in a substantially regular manner, at a constant pitch. The strips 311 are for example made of a conductive material, for example a metal such as copper, or a metal alloy. For the purpose of simplifying the manufacture of the elementary cell 105, the strips 311 of the polarizer 207b are for example made of the same material as the strips 301 of the polarizer 207a.

[0067] When the antenna 100 operates in transmission, the polarizer 207b is for example adapted to control the transmission, towards the external medium, of waves coming from the radiating elements 203-1 and 203-2. The polarizer 207b makes it possible more precisely to transmit, towards the external medium, incident waves having a polarization substantially identical to that of the polarizer 207b, that is to say a rectilinear polarization substantially orthogonal to the bands 311, and to reflect waves in incident having a polarization different from that of the polarizer 207b, that is to say a rectilinear polarization parallel to the bands 311.

[0068] [Fig. 4] is a top view, schematic and partial, of a variant of the radiating element 203-1 of the elementary cell 105 of [Fig. 2]. [Fig. 4] illustrates more precisely a radiating element 403 capable of being integrated into the elementary cell 105, for example as a replacement for the radiating element 203-1 described above in relation to [Fig. 3B]. In this case, the elementary cell 105 comprises for example another radiating element similar to the radiating element 403, but produced for example in another metallization level of the interconnection stack 204 and rotated by approximately 90° relative to the radiating element 403.

[0069] In the example shown, the radiating element 403 comprises two parts 405-1 and 405-2, for example similar to the parts 305-1 and 305-2 of the radiating element 203-1. In this example, each part 405-1, 405-2 of the radiating element 403 more precisely comprises a vertical bar extending laterally above the face 201b of the semiconductor substrate 201 along a diameter of a circle 407. In [Fig.4], the parts 405-1 and 405-2 of the radiating element 403 are connected by a switch 409, for example similar or identical to the switch 309 connecting the parts 305-1 and 305-2 of the radiating element 203-1. In the illustrated example, each portion 405-1, 405-2 of the radiating element 403 further comprises a horizontal bar, or upper bar, in the shape of an arc of a circle and curved along the periphery of the circle 407.

[0070] In the orientation of [Fig. 4], the left and right ends of the upper bar of the T formed by the portion 405-1 of the radiating element 403 are connected respectively, by switches 411-1 and 411-2, to regions 413-1 and 413-2. In the example shown, the regions 413-1 and 413-2 each have the shape of an arc of a circle extending laterally along the periphery of the circle 407, in the extension of the upper bar of the T formed by the portion 405-1 of the radiating element 403. Similarly, the left and right ends of the upper bar of the T formed by the portion 405-2 of the radiating element 403 are connected respectively, by switches 411-3 and 411-4, to regions 413-3 and 413-4. In the example shown, the regions 413-3 and 413-4 each have the shape of an arc of a circle extending laterally along the periphery of the circle 407, in the extension of the upper bar of the T formed by the part 405-2 of the radiating element 403.

[0071] In the example shown, the upper bars of the Ts formed by the parts 405-1 and 405-2 of the radiating element 403 have an adjustable length. In this example, the control of the switches 411-1, 411-2, 411-3 and 411-4 makes it possible to vary the length of the upper bars of the Ts formed by the parts 405-1 and 405-2 of the radiating element 403. In the example shown, the length of the upper bar of the T of the portion 405-1 of the radiating element 403 is increased by closing the switches 411-1 and 411-2, and decreased by opening the switches 411-1 and 411-2. The switches 411-2 and 411-2 are preferably controlled substantially simultaneously in opening or closing. Similarly, the length of the upper bar of the T of the portion 405-2 of the radiating element 403 is increased by closing the switches 411-3 and 411-4, and decreased by opening the switches 411-3 and 411-4. The switches 411-3 and 411-4 are preferably controlled substantially simultaneously in opening or closing.

[0072] An advantage of the radiating element 403 lies in the fact that it advantageously makes it possible to obtain more phase states, and therefore more precise control of the orientation of the beam emitted by the antenna 100, compared to the case where the elementary cell 105 comprises the radiating element 203.

[0073] Generally speaking, providing an integer number N greater than or equal to two of switches in the elementary cell 105 gives access to a number Nl of phase quantization bits.

[0074] Although [Fig. 4] illustrates an example in which each part 405-1, 405-2 of the radiating element 403 comprises two regions connected respectively, by two switches, to the upper bar of the T formed by said part, this example is not limiting. As a variant, each part 405-1, 405-2 may comprise an even number and greater than two of regions in the shape of an arc of a circle connected to each other and to the upper bar of the T formed by said part by an even number and greater than two of switches. This makes it possible to access even more phase states.

[0075] [Fig. 5] is a schematic and partial side and sectional view of a transmitter network of a radio antenna, for example the transmitter network 103 of the antenna 100 previously described in relation to [Fig. 1], according to one embodiment.

[0076] In the example shown, the semiconductor substrate 201 and the interconnection stack 204 are common to several elementary cells 105 of the transmitter network 103 (two elementary cells 105, in the example shown). In a case where the insulating regions 205a and 205b and the polarizers 207a and 207b are formed respectively in insulating layers and in metallization levels of a printed circuit board, the semiconductor substrate 201 and the interconnection stack 204 are for example located in a cavity formed in the thickness of the printed circuit board.

[0077] In the example illustrated, the transmitter network 103 comprises contact recovery elements 501a and 501b making it possible to provide supply and control voltages for the switches associated with the radiating elements 203-1 and 203-2. the example shown, the contact recovery elements 501a comprise conductive tracks located on and in contact with the face 201a of the semiconductor substrate 201, conductive vias passing through the thickness of the insulating region 205a and conductive vias extending in the thickness of the substrate 201 from its face 201a to the regions 209 in which the switches are formed. Similarly, the contact recovery elements 501b comprise conductive tracks extending on and in contact with the upper face of the interconnection stack 204 to the radiating elements 203-1 and 203-2, and conductive vias passing through the thickness of the insulating region 205b. Alternatively, the switches of the regions 209 may be connected to the contact recovery elements 501b by conductive traces and conductive vias located in the interconnect stack 204.

[0078] For example, the semiconductor substrate 201 is part of an integrated circuit chip mechanically bonded to the printed circuit board comprising the insulating regions 205a and 205b and the polarizers 207a and 207b by techniques implemented in the surface mounting of electronic components, for example by soldering or by means of solder balls, for example on the side of the region 205a.

[0079] Although [Fig. 5] illustrates an example in which two elementary cells are formed in and on the same substrate, this example is not limiting. More generally, all or part of the elementary cells 105 of the transmitter network 103 can be formed in and on the same substrate. Furthermore, although this has not been shown in [Fig. 5], control and power supply circuits can be provided in the printed circuit board. These circuits can for example comprise shift registers, flip-flops, buffer circuits, etc. adapted to control the switches of the elementary cells 105 to the open state or to the closed state depending on the desired orientation of the beam emitted or received by the antenna 100.

[0080] By way of example, the transmitter network 103 may further comprise control and bias circuits (not illustrated in [Fig.5]) for the switches of the elementary cells 105. Generally, the transmitter network 103 may comprise any number of control and bias circuits associated with any number of sets of elementary cells, each comprising several elementary cells formed on the same semiconductor substrate.

[0081] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will occur to those skilled in the art. In particular, those skilled in the art are able to adapt the number of regions 413-1, 413-2, 413-3 and 413-4 as well as the number of switches 411-1, 411-2, 411-3 and 411-4 of the radiating element 403 depending on the intended application. The person skilled in the art is further able to choose the length of each region 413-1, 413-2, 413-3 and 413-4 depending on the desired phase states.

[0082] Finally, the practical implementation of the embodiments and variants described is within the reach of the person skilled in the art from the functional indications given above. In particular, the person skilled in the art is capable of providing for the integration into the semiconductor substrate 201 of electronic components such as power amplifiers, control circuits, a memory or a processing unit making it possible to control the open or closed states of the different switches of the radiating elements, etc.

Claims

Claims

1. A transmitting array antenna cell (105) comprising: - a semiconductor substrate (201); - a first polarizer (207a), located on the side of a first face (201a) of the semiconductor substrate; - a second polarizer (207b), located on the side of a second face (201b) of the semiconductor substrate opposite the first face; and - at least one radiating element (203-1, 203-2; 403) interposed between the second face (201b) of the semiconductor substrate and the second polarizer (207b), said at least one radiating element being adapted to switch between at least two phase states.

2. Cell (105) according to claim 1, wherein each radiating element (203-1, 203-2; 403) comprises at least two parts (305-1, 305-2, 305-3, 305-4; 405-1, 405-2) connected by a switch (309; 409) formed in the semiconductor substrate (201).

3. Cell (105) according to claim 2, wherein said at least one radiating element (203-1, 203-2; 403) comprises exactly first (305-1, 305-3; 405-1) and second (305-2, 305-4; 405-2) parts each having, in top view, a T shape.

4. Cell (105) according to claim 3, comprising exactly first (203-1; 403) and second (203-2) radiating elements forming, in top view, a cross of which a first branch comprises the first (305-1; 405-1) and second (305-2; 405-2) parts of the first radiating element, and of which a second branch, substantially orthogonal to the first branch, comprises the first (305-3) and second (305-4) parts of the second radiating element.

5. Cell (105) according to claim 3 or 4, in which the upper bar of the T formed by each part (305-1, 305-2, 305-3, 305-4; 405-1, 405-2) of each radiating element (203-1, 203-2; 403) has an adjustable length.

6. Cell (105) according to any one of claims 1 to 5, wherein each radiating element (203-1, 203-2; 403) is located on and in contact with the second face (201b) of the semiconductor substrate (201).

7. Cell (105) according to any one of claims 1 to 6, wherein: - the first polarizer (207a) comprises a plurality of first conductive strips (301) substantially parallel to each other; and - the second polarizer (207b) comprises a plurality of second conductive strips (311) substantially parallel to each other and substantially orthogonal to the first conductive strips.

8. Cell (105) according to any one of claims 1 to 7, further comprising: - a first insulating region (205a) interposed between the first face (201a) of the semiconductor substrate (201) and the first polarizer (207a); and - a second insulating region (205b) interposed between the second face (201b) of the semiconductor substrate and the second polarizer (207b).

9. The cell (105) of claim 8, wherein the first (205a) and second (205b) insulating regions are part of insulating layers of a printed circuit board, each radiating element (203-1, 203-2; 403) and the first (207a) and second (207b) polarizers being formed in metallization levels of the printed circuit board.

10. Cell according to any one of claims 1 to 9, in which the radiating element(s) (203-1, 203-2; 403) are formed in at least one metallization level of an interconnection stack (204) interposed between the semiconductor substrate (201) and the second polarizer (207b).

11. A transmitter network (103) comprising a plurality of cells (105) according to any one of claims 1 to 10.

12. The array (103) of claim 11, wherein the semiconductor substrate (201) is common to multiple cells (105) of the array.

13. An antenna (100) comprising a transmitter array (103) according to claim 11 or 12 and at least one source (101) configured to irradiate one face of the array.

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