Patent Application
20240275417
The present disclosure generally concerns electronic devices and, more particularly, the field of transmitarray antennas.
Among the different existing radio communication antenna technologies, so-called “transmitarray” radio antennas are particularly known. These antennas generally comprise a plurality of elementary cells, each comprising a first antenna element irradiated by an electromagnetic field emitted by one or a plurality of sources, a second antenna element transmitting a modified signal to the outside of the antenna, and a coupling element between the first and second antenna elements.
Existing transmitarray antennas however suffer from various disadvantages.
There exists a need to improve existing transmitarray antennas. It would in particular be desirable to have transmitarray antennas adapted to implementing a simultaneous bidirectional communication.
For this purpose, an embodiment provides a cell of a transmitarray adapted to implementing a full-duplex communication, the cell comprising:
According to an embodiment, the transmit channel is adapted to transmitting a first signal having a first polarization state, and the receive channel is adapted to receiving a second signal having a second polarization state, different from the first polarization state.
According to an embodiment, the first and second signals have orthogonal linear polarizations.
According to an embodiment, the first and second signals have circular and linear polarizations, respectively.
According to an embodiment, each of the first and second antenna elements comprises a substantially square-shaped conductive plane and first and second ports respectively located in the vicinity of first and second adjacent sides of the conductive plane.
According to an embodiment, the first and second ports of the first antenna element are respectively located vertically in line with the first and second ports of the second antenna element.
According to an embodiment, the first and second ports of the first antenna element are respectively coupled, by the first and second phase-shift and amplifier circuits, to the first and second ports of the second antenna element.
According to an embodiment, the first and second ports of the first antenna element are respectively coupled, by the first and second phase-shift and amplifier circuits, to the second and first ports of the second antenna element.
According to an embodiment, the cell further comprises first and second ground planes interposed between the first antenna element and the second antenna element.
According to an embodiment, the first and second phase-shift and amplifier circuits are interposed between the first and second ground planes.
According to an embodiment, the first and second antenna elements and the first and second ground planes are formed in conductive levels of a printed circuit board.
According to an embodiment, the transmit and receive channels each comprise a phase-shift circuit and an amplifier circuit series-connected between the first antenna element and the second antenna element.
An embodiment provides a transmitarray comprising a plurality of cells such as described.
According to an embodiment, the first antenna element of each cell is electrically isolated from the first antenna element of each of the other cells, and the second antenna element of each cell is electrically isolated from the second antenna element of each of the other cells.
An embodiment provides an antenna comprising a transmitarray such as described and at least one source configured to irradiate a surface of the array.
The foregoing features and advantages, as well as others, will be described in detail in the rest of the disclosure of specific embodiments given by way of illustration and not limitation with reference to the accompanying drawings, in which:
Like features have been designated by like references in the various figures. In particular, the structural and/or functional features that are common among the various embodiments may have the same references and may dispose identical structural, dimensional and material properties.
For the sake of clarity, only the steps and elements that are useful for the understanding of the described embodiments have been illustrated and described in detail. In particular, embodiments of an elementary cell for a transmitarray antenna are described hereafter. The structure and the operation of the primary source(s) of the antenna, intended to irradiate the transmitarray, will however not be detailed, the described embodiments being compatible with all or most known primary irradiation sources for transmitarray antennas. As an example, each primary source is adapted to generating a beam of generally conical shape irradiating all or part of the transmitarray. Each primary source comprises, for example, a horn antenna. As an example, the central axis of each primary source is substantially orthogonal to the mean plane of the array.
Further, the methods for manufacturing the described transmit arrays will not be detailed, the forming of the described structures being within the abilities of those skilled in the art based on the indications of the present disclosure, for example by implementing usual printed circuit manufacturing techniques.
Unless indicated otherwise, when reference is made to two elements connected together, this signifies a direct connection without any intermediate elements other than conductors, and when reference is made to two elements coupled together, this signifies that these two elements can be connected or they can be coupled via one or a plurality of other elements.
In the following description, when reference is made to terms qualifying absolute positions, such as terms “front”, “back”, “top”, “bottom”, “left”, “right”, etc., or relative positions, such as terms “above”, “under”, “upper”, “lower”, etc., or to terms qualifying directions, such as terms “horizontal”, “vertical”, etc., it is referred, unless specified otherwise, to the orientation of the drawings.
Unless specified otherwise, the expressions “about”, “approximately”, “substantially”, and “in the order of” signify plus or minus 10%, preferably of plus or minus 5%.
Antenna 100 typically comprises one or a plurality of primary sources 101 (a single source 101, in the shown example) irradiating a transmitarray 103. Source 101 may have any polarization, for example linear or circular. Array 103 comprises a plurality of elementary cells 105, for example arranged in an array of rows and columns. Each cell 105 typically comprises a first antenna element 105a, located on the side of a first surface of array 103 arranged in front of primary source 101, and a second antenna element 105b, located on the side of a second surface of the array opposite to the first surface. The second surface of array 103 for example faces a transmitting medium, or outside environment, of antenna 100.
Each cell 105 is capable, in transmit mode, of receiving an electromagnetic radiation on its first antenna element 105a and of transmitting back this radiation from its second antenna element 105b, for example by introducing a known phase shift ϕ. In receive mode, each cell 105 is capable of receiving an electromagnetic radiation on its second antenna element 105b and of transmitting back this radiation from its first antenna element 105a, towards source 101, with the same phase shift ϕ. The radiation transmitted back by the first antenna element 105a is, for example, focused on source 101.
The characteristics of the near-field or far-field radiation generated by antenna 100, in particular its shape (or gauge), its intensity and its maximum transmission direction (or pointing direction), depend on the values of the phase shifts respectively introduced by the various cells 105 of array 103.
Transmitarray antennas have the advantages, among others, of having a good power efficiency and of being relatively simple, inexpensive, and compact. This is in particular due to the fact that transmit arrays are implementable in planar technology, generally on a printed circuit.
The present disclosure more particularly concerns reconfigurable transmitarray antennas 103. Transmitarray 103 is said to be reconfigurable when elementary cells 105 are individually electronically controllable to modify their phase shift value ϕ and/or their amplitude, which enables to dynamically modify the characteristics of the radiation generated by the antenna, and in particular to modify its pointing direction without mechanically moving the antenna or a portion of the antenna by means of a motorized element.
In the shown example, each elementary cell 105 of transmitarray 103 comprises a transmit channel 201a and a receive channel 201b respectively intended to transmit and to receive signals, for example simultaneously. Within each cell 105, each channel 201a, 201b couples the first antenna element 105a to the second antenna element 105b of the cell. In the shown example, for each cell 105, the first antenna element 105a connects a first end of transmit channel 201a to a first end of receive channel 201b. Similarly, the second antenna element 105b of cell 105 connects a second end of transmit channel 201a, opposite to the first end of channel 201a, to a second end of receive channel 201b, opposite to the first end of channel 201b. Further, the first antenna element 105a of each elementary cell 105 is electrically isolated from the first antenna element 105a of each of the other cells 105, and the second antenna element 105b of each elementary cell 105 is electrically isolated from the second antenna element 105b of each of the other cells 105.
Each transmit channel 201a comprises a phase-shift and amplifier circuit 203a, and each receive channel 201b comprises a phase-shift and amplifier circuit 203b. In the shown example, each phase-shift and amplifier circuit 203a, 203b comprises, between the first and second antenna elements 105a and 105b, a phase-shift circuit 205a, 205b associated in series with an amplifier circuit 207a, 207b.
The phase-shift circuit 205a of transmit channel 201a comprises a terminal coupled, preferably connected, to the first antenna element 105a and another terminal coupled, preferably connected, to a terminal, for example an input terminal, of amplifier circuit 207a, amplifier circuit 207a further comprising another terminal, for example an output terminal, coupled, preferably connected, to the second antenna element 105b. Further, the amplification circuit 270b of receive channel 201b comprises a terminal, for example an input terminal, coupled, preferably connected, to the second antenna element 105b and another terminal, for example an output terminal, coupled, preferably connected, to a terminal of phase-shift circuit 205b, phase-shift circuit 205b further comprising another terminal coupled, preferably connected, to the first antenna element 105a.
As an example, each phase-shift circuit 205a, 205b comprises at least one element selected from among a diode, for example a PIN diode, a microelectromechanical system, a varicap or varactor diode, an integrated phase-shift circuit, etc. Each phase-shift circuit 205a, 205b, for example, receives a control signal originating from a control circuit (not shown in
The amplifier circuit 207a of transmit channel 201a is, for example, a power amplifier, for example a Class-A linear amplifier in CMOS (Complementary Metal-Oxide-Semiconductor) SOI (Silicon On Insulator) technology, for example of the type described in the article by A. Hamani, A. Siligaris, B. Blampey, and J. L. G. Jimenez entitled “167-GHz and 155-GHz High Gain D-band Power Amplifiers in CMOS SOI 45-nmos”, from the fifteenth European Microwave Integrated Circuits Conference (EuMIC) in Utrecht, Netherlands, 2021, pages 261-264.
The amplification circuit 207b of receive channel 201b is, for example, a low-noise amplifier (LNA). This enables to optimize the noise figure of receive channel 201b. As an example, each amplifier circuit 207b comprises a class-“AB” amplifier for example comprising one or two operating stages. Each amplifier circuit 207b for example has an electrical power in the range from 10 to 20 mW.
In the shown example, the source 101 of transmitarray antenna 200 is connected to an interference canceller circuit 211. More specifically, in this example, first and second links 213a and 213b, electrically isolated from each other, connect circuit 211 to source 101.
Antenna 200 also comprises a processing circuit 215 connected to circuit 211. In the shown example, circuit 215 is connected to circuit 211 by a transmit channel 217a comprising a digital-to-analog converter 219a associated in series with a mixer 221a (x). Circuit 211 is further coupled to circuit 215 by a receive channel 217b comprising a mixer 221b (x) associated in series with an analog-to-digital converter 219b. Each mixer 221a, 221b is connected to an oscillator 223a, 223b (˜), for example a voltage-controlled oscillator (VCO) or a phase-locked loop (PLL).
In the shown example, the digital-to-analog converter 219a of transmit channel 217a has input and output terminals respectively connected to circuit 215 and to a terminal of mixer 221a, mixer 221a further having another terminal connected to circuit 211. Further, in this example, the mixer 221b of receive channel 217b comprises a terminal connected to circuit 211 and another terminal connected to an input terminal of an analog-to-digital converter 219b, analog-to-digital converter 219b further comprising an output terminal connected to circuit 215.
As an example, circuit 215 is adapted to encoding and to modulating a signal to be transmitted by transmit channel 217a, and to demodulating and to decoding a signal received by receive channel 217b.
Antenna 200 is configured to implement a full-duplex communication, that is, antenna 200 can transmit and receive signals simultaneously in a same frequency band (“In-Band Full-Duplex”—IBFD). In particular, antenna 200 differs from frequency division multiple access (FDMA) antennas, which have transmit and receive channels with separated frequencies. A first signal to be transmitted is for example generated by circuit 215 and then transmitted, via transmit channel 217a and first link 213a, to source 101 irradiating array 103. The first signal then reaches the first antenna elements 105a of the cells 105 of array 103 and is then transmitted, via transmit channels 201a, to the second antenna elements 105b to be radiated towards the outside environment. At the same time, a second signal to be received from the outside environment is, for example, picked up by the second antenna elements 105b of the cells 105 of array 103 and then transmitted, via receive channels 201b, to the first antenna elements 105a. The second signal is then radiated towards source 101 and is then transmitted, via second link 213b and receive channel 217b, to circuit 215 in order to be processed.
In transmit mode, the first antenna element 105a receives the signal radiated by antenna 101. The signal is then phase-shifted and amplified by transmit channel 201a, more precisely by phase-shift circuit 205a and by amplification circuit 207a, respectively, and then transmitted back by the second antenna element 105b towards the outside environment. In receive mode, the second antenna element 105b receives the signal from the outside environment. The signal is then amplified and phase-shifted by receive channel 201b, more precisely by amplifier circuit 207b and by phase-shift circuit 205b, respectively, and then transmitted back by the first antenna element to source 101.
The signals transmitted and received by antenna 200 respectively have distinct first and second polarization states or directions. As an example, the transmitted and received signals have first and second linear polarizations orthogonal to each other, the first polarization for example being a linear polarization called “vertical” and the second polarization a linear polarization called “horizontal”.
As a variant, at least one of the first and second polarizations may be a circular polarization. In this case, the first and second polarizations may be circular polarizations in opposite directions, the first polarization being, for example, a “left-hand” circular polarization (counter-clockwise, from the point of view of source 101) and the second polarization being, for example, a “right-hand” circular polarization (clockwise, from the point of view of source 101), or the first polarization being a circular polarization and the second polarization being a linear polarization. The fact of providing for the signals transmitted and received by the antenna to respectively have circular and linear polarizations advantageously enables to obtain a better separation of these signals.
In
An advantage of the antenna 200 of
In the shown example, cell 105 comprises two separate ground planes M1 and M2 substantially parallel to each other and interposed between the first and second antenna elements 105b. The first and second antenna elements 105a and 105b are, in this example, substantially parallel to each other and to ground planes M1 and M2. In the shown example, circuits 203a and 203b are interposed between ground planes M1 and M2.
In the example shown in
As an example, the first and second antenna elements 105a and 105b and ground planes M1 and M2 are formed in conductive levels or metallization levels of a printed circuit board (PCB), the conductive levels being separated from one another by insulating levels, not shown in
In the shown example, the first antenna element 105a is a patch antenna comprising a substantially square conductive plane having vias V1a and V1b connected thereto via ports P1 and P2, respectively. This example is however not limiting, and the conductive plane of the first antenna element 105a may have any shape, for example rectangular. In the shown example, port P1 is located in the vicinity of a first side of the square formed by the conductive plane and port P2 is located in the vicinity of a second side of the square adjacent to the first side. In this example, ports P1 and P2 are substantially aligned with the middles of the first and second sides, respectively.
In the shown example, the first antenna element 105a is adapted to transmitting, via port P1, a first signal having a linear polarization (a horizontal polarization, in the orientation of
Although this has not been shown in the drawings, the second antenna element 105b is, for example, similar or identical to the first antenna element 105a. As an example, the ports P1 and P2 of the second antenna element 105b are located respectively vertically in line with the ports P1 and P2 of the first antenna element 105a. In this case, vias V2a and V2b are, for example, located respectively vertically in line with vias V1a and V1b.
In the shown example, vias V1a and V1b are electrically isolated from ground plane M1. Similarly, vias V2a and V2b are for example electrically isolated from ground plane M2, ground plane M2 being for example similar or identical to ground plane M1.
In the shown example, cell 105 more precisely comprises:
Although this has not been detailed in the drawings to avoid overloading the drawing, cell 105 may further comprise one or a plurality of layers (“Redistribution Layers”—RDL) of redistribution of the transmitted and received radio frequency signals, of a ground signal, and of a power supply signal.
Similarly, cell 105 further comprises:
In the shown example, tracks P1a and P1b are substantially parallel to each other, and tracks P2a and P2b are substantially parallel to each other and orthogonal to tracks P1a and P1b.
An advantage of the embodiment of cell 105 described above in relation with
Various embodiments and variants have been described. Those skilled in the art will understand that certain features of these various embodiments and variants may be combined, and other variants will occur to those skilled in the art. In particular, the embodiment of cell 105 detailed hereabove in relation with
Finally, the practical implementation of the described embodiments and variants is within the abilities of those skilled in the art based on the functional indications given hereabove. In particular, the practical forming of the amplifier and phase-shift circuits 203a and 203b of transmit and receive channels 201a and 201b is within the abilities of those skilled in the art based on the indications of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2301423 | Feb 2023 | FR | national |
