Dual-function amplification device for an active antenna

Abstract

The present invention relates to a dual-function amplification device (18) for an active antenna (10), the amplification device (18) comprising: - an amplifier (20) able to be controlled in three operating modes from among an inactive mode, an active transmission mode and an active reception mode, the amplifier (20) being configured with a balanced architecture, - a switch (22) able to be controlled between two switching modes, such that: when the amplifier (20) is in active transmission mode, the switch (22), in the first switching mode, connects an input transmission channel to an output transmission channel of the amplifier (20), and when the amplifier (20) is in active reception mode, the switch (22), in the second switching mode, connects an input reception channel to an output reception channel of the amplifier (20).

Description

[0001] DESCRIPTION

[0002] TITLE: Dual-function amplification device for an active antenna

[0003] The present invention relates to a dual-function amplification device for an active antenna. The present invention also relates to an associated amplification assembly and an associated active antenna.

[0004] The invention concerns the way of producing the "front-end" of active antennas (Transmission-Reception) used in particular in the fields of radar and telecommunications (5G, etc.).

[0005] The need is to produce highly integrated active antennas (AESA for "Active Electronically Scanned Array"), particularly from the X band and beyond, or at lower bands (S, C, etc.). To achieve this, it is necessary to simplify the architecture of the transceiver modules so as to integrate the transceiver function into a reduced space that can more easily fit into the network mesh.

[0006] State-of-the-art solutions use circulator-isolator based transmit-receive architectures, or solutions based on switches integrating transistors.

[0007] However, these solutions are often multi-chip, i.e. grouped in a packaging (SIP for "System in Package"), and therefore expensive. They are, moreover, most often not compliant with a two-dimensional mesh, from the X band, Ku and beyond.

[0008] In particular, when ferrite duplexers are used, these duplexers generate a penalizing footprint (surface-volume) and are also expensive.

[0009] When switches are used, the footprint is reduced. However, these switches generate losses and limit the transmission-reception budget (radar in particular). Switching times and power handling are also limiting depending on the technology used.

[0010] There is therefore a need for an alternative transmit / receive amplification device for an active antenna that is compact.

[0011] For this purpose, the present description relates to a dual-function amplification device for an active antenna, the amplification device comprising:

[0012] - an amplifier capable of being controlled according to three operating modes among:

[0013] • an inactive mode, • an active transmission mode in which the amplifier operates as a high-power amplifier,

[0014] • an active reception mode in which the amplifier operates as a low noise amplifier, the amplifier being configured according to a balanced architecture with two input channels and two output channels among:

[0015] • a transmission input channel intended to be connected to a transmitter of a transmission signal,

[0016] • a reception input channel intended to be connected to a radiating element of an active antenna,

[0017] • a transmission output channel intended to be connected to the same radiating element of the active antenna,

[0018] • a reception output channel intended to be connected to a receiver of a reception signal,

[0019] - a switch capable of being controlled between two switching modes so that:

[0020] • when the amplifier is in the active transmit mode, the switch in the first switch mode connects the transmit input channel to the transmit output channel of the amplifier, and

[0021] • when the amplifier is in active receive mode, the switch in the second switch mode connects the receive input channel to the receive output channel of the amplifier.

[0022] According to particular embodiments, the amplification device comprises one or more of the following characteristics, taken in isolation or in all technically possible combinations:

[0023] - the switch is also capable of being controlled so that when the amplifier is in the inactive mode, the switch in the first switch mode connects the output channel in transmission to the output channel in reception;

[0024] - the amplifier and the switch are capable of being controlled according to the useful signal so that:

[0025] - when the useful signal is a transmission signal from the transmitter, the amplifier is controlled in the active transmission mode and the switch is in the first switch mode,

[0026] - when the useful signal is a reception signal and the amplitude of the useful signal is less than a predetermined threshold, the amplifier is controlled in the active reception mode and the switch is in the second switch mode; - the amplifier and the switch are capable of being controlled as a function of the useful signal so that when the useful signal is a reception signal and the amplitude of the useful signal is greater than or equal to the predetermined threshold, the amplifier is controlled in the inactive mode and the switch is in the first switch mode;

[0027] - the amplifier is made on a single active cell;

[0028] - the switch is without transistor switches;

[0029] - the switch includes diodes whose activation and deactivation allow the transition from the first switch mode to the second switch mode, and vice versa;

[0030] - the switch includes:

[0031] - a first diode connected in parallel to the reception input channel, and

[0032] - a second diode connected in parallel to the output channel in transmission;

[0033] - the useful signal has a useful wavelength, each of the first diode and the second diode being positioned at a distance substantially equal to a quarter of the wavelength of the useful signal relative to the common point of the switch intended to be connected to the radiating element;

[0034] - the first switching mode corresponds to the activation of the first diode and the deactivation of the second diode, and

[0035] - the second switching mode corresponds to the deactivation of the first diode and the activation of the second diode;

[0036] - the amplifier is voltage driven, the amplifier comprising transistors polarized differently between the active mode in transmission and the active mode in reception depending on the driving voltage.

[0037] The present description also relates to an amplification assembly comprising two amplification devices as described previously, the transmission input channels of the amplifiers of the two amplification devices being intended to be connected to the same transmitter of a transmission signal.

[0038] According to particular embodiments, the amplification assembly comprises a phase shifter on the transmission input channel of one of the amplifiers so as to phase shift the transmission signal arriving on said transmission input channel relative to the transmission input channel of the other amplifier.

[0039] The present description also relates to an active antenna, for example for a radar, comprising:

[0040] - a transmitter of a transmission signal,

[0041] - a receiver of a reception signal,

[0042] - a radiating element, and - at least one amplification device as described previously, the transmission input channel(s) of the amplifier(s) being connected to the transmitter, the reception output channel(s) of the amplifier(s) being connected to the receiver, the transmission output channel(s) and the reception input channel(s) being connected to the radiating element.

[0043] Other characteristics and advantages of the invention will appear on reading the following description of embodiments of the invention, given by way of example only and with reference to the drawings which are:

[0044] [Fig 1], Figure 1, a schematic representation of an example of an active antenna comprising a transmitter, a receiver, a radiating element and at least one amplification device,

[0045] [Fig 2], Figure 2, a schematic representation of an example of an amplification device,

[0046] [Fig 3], Figure 3, a schematic representation of an exemplary embodiment of the amplification device of Figure 2, the amplification device being in a transmission mode,

[0047] [Fig 4], Figure 4, a schematic representation of the amplification device of Figure 3, the amplification device being in a standard reception mode,

[0048] [Fig 5], Figure 5, a schematic representation of the amplification device of Figures 3 and 4, the amplification device being in a gain-free receive mode, and [Fig 6], Figure 6, a schematic representation of an example of an amplification assembly comprising two amplification devices such as those of Figures 3 to 5.

[0049] An example of an active antenna 10 is illustrated in FIG. 1. An active antenna is an antenna amplifying the useful signal over an operating frequency band of the antenna. Such an active antenna performs two types of amplification, namely amplification of the signal to be transmitted (power amplification, in English HPA “High power Amplifier”), and low noise amplification of the received signal (in English LNA “Low Noise Amplifier”).

[0050] The active antenna 10 (front-end, i.e. front part) comprises a transmitter 12, a receiver 14, at least one radiating element 16 and an amplification device 18.

[0051] The transmitter 12 is capable of transmitting a transmission signal Tx. The transmission signal Tx is intended to be sent to the radiating element 16.

[0052] The receiver 14 is capable of receiving a reception signal Rx. The reception signal Rx comes from the radiating element 16. The radiating element 16 is capable of transmitting the transmission signal Tx to the outside and of receiving the reception signal Rx from the outside.

[0053] The amplification device 18 is a dual-function device, i.e. capable of performing both a high-power amplification function and a low-noise amplification function, depending on the operating conditions.

[0054] The amplification device 18 comprises an amplifier 20 (single) and a switch 22.

[0055] The amplifier 20 is produced according to a balanced architecture (topology) based on the use of LANGE couplers. A balanced architecture is a type of architecture having two input channels, one of which is isolated, and two output channels, one of which is isolated. The principle is that a signal entering a non-isolated input channel exits via a non-isolated output channel. In practice, in the present case, the LANGE couplers of the amplifier 20 are devoid of resistance on all the channels (therefore also on the isolated channels), and each channel is connected either to the transmitter 12, or to the receiver 14, or to the radiating element 16.

[0056] Preferably, the amplifier 20 is produced on a single active cell, for example the same monolithic integrated circuit.

[0057] Preferably, the amplifier 20 is capable of operating for at least one of the following frequency bands: the S band (2 GHz-4 GHz), the C band (4 GHz - 8 GHz), the X band (8 GHz-12 GHz), the Ku band (12 GHz-18 GHz), the K band (18 GHz - 27 GHz) and the Ka band (27 GHz-40 GHz).

[0058] The amplifier 20 is capable of being controlled according to three operating modes among:

[0059] - an active transmission mode in which the amplifier 20 operates as a high power amplifier (HPA). In this case, the amplifier 20 is, for example, suitable for amplifying signals whose output power can reach a few tens of mW up to a few Watts.

[0060] - an active reception mode in which the amplifier 20 operates as a low noise amplifier (LNA). In this case, the amplifier 20 is, for example, capable of amplifying signals with an amplitude extending, for example, from -150 to 0 dBm.

[0061] - an inactive mode corresponding to a deactivation of the amplifier 20. In this case, the signal does not pass through the amplifier 20.

[0062] Preferably, the amplifier 20 is voltage driven. Alternatively, the amplifier 20 is current driven. In one example, the amplifier 20 comprises transistors biased differently between the active mode in transmission and the active mode in reception depending on the driving voltage (or the driving current).

[0063] Thus, in the example of Figure 3, the amplifier 20 is driven in active mode in transmission with a driving voltage V_HPA and operates in HPA. In the example of Figure 4, the amplifier 20 is driven in active mode in reception with a driving voltage V_LNA and operates in LNA. In the example of Figure 5, the amplifier 20 is in an inactive mode and its driving voltage is deactivated (OFF mode: V OFF).

[0064] Amplifier 20 has two input channels and two output channels among:

[0065] • a transmission input channel 30 intended to be connected to a transmitter 12 of a transmission signal Tx,

[0066] • a reception input channel 32 intended to be connected to the radiating element 16 of the active antenna 10,

[0067] • a transmission output channel 34 intended to be connected to the radiating element 16 of the active antenna 10,

[0068] • a reception output channel 36 intended to be connected to a receiver 14 of a reception signal Rx.

[0069] According to the balanced architecture, the input channels in transmission 30 and reception 32 are independently split, amplified and then recombined by the amplifier 20. In transmission, the recombination is carried out on channel 34 and in reception on channel 36.

[0070] Switch 22 is suitable for being controlled between two switching modes so that:

[0071] - when the amplifier 20 is in the active transmission mode, the switch 22 in the first switching mode, connects the transmission input channel 30 to the transmission output channel 34 of the amplifier 20 (figure 3).

[0072] - when the amplifier 20 is in the active reception mode, the switch 22 in the second switch mode, connects the reception input channel 32 to the reception output channel 36 of the amplifier 20 (figure 4).

[0073] Preferably, the switch 22 is also capable of being controlled so that when the amplifier 20 is in the inactive mode, the switch 22 in the first switch mode connects the transmit output channel 34 to the receive output channel 36 (figure 5).

[0074] More precisely in an exemplary implementation, the amplifier 20 and the switch 22 are capable of being controlled as a function of the useful signal (i.e. the transmission signal Tx or the reception signal Rx) so that: - when the useful signal is a transmission signal Tx coming from the transmitter 12, the amplifier 20 is controlled in the active transmission mode and the switch 22 is controlled in the first switching mode. The amplification device 18 then operates in a transmission mode.

[0075] - when the useful signal is an Rx reception signal and the amplitude of the useful signal is less than a predetermined threshold, the amplifier 20 is controlled in the active reception mode and the switch 22 is controlled in the second switch mode. The amplification device 18 then operates in a standard reception mode (with minimum reception gain and noise factor).

[0076] - when the useful signal is an Rx reception signal and the amplitude of the useful signal is greater than or equal to the predetermined threshold, the amplifier 20 is controlled in the inactive mode and the switch 22 is in the first switch mode. The amplification device 18 then operates in a reception mode without gain (no reception gain).

[0077] The predetermined threshold is linked to the saturation threshold of the complete reception chain. It can be, for example, equal to -20dBm.

[0078] In an exemplary implementation as illustrated in Figures 3 to 5, the switch 22 comprises diodes whose activation and deactivation allow the transition from the first switch mode to the second switch mode, and vice versa.

[0079] Diodes are, for example, PIN diodes (from the English "Positive Intrinsic Negative diode").

[0080] Preferably, the switch 22 is devoid of transistor switches.

[0081] Preferably, the switch 22 comprises only diodes.

[0082] In an exemplary implementation, switch 22 includes:

[0083] - a first diode 40 is connected in parallel to the reception input channel 32, and

[0084] - a second diode 42 is connected in parallel to the emission output channel 34.

[0085] In this example, each of the diodes 40 and 42 is positioned at a determined distance from the common point of the switch 22 intended to be connected to the radiating element 16, the distance being substantially equal to a quarter of the wavelength of the useful signal.

[0086] The first switching mode corresponds to the activation of the first diode 40 and the deactivation of the second diode 42. The activated first diode 40 then acts as a short circuit, bringing a high impedance to the common point of the switching 22, thus directing the signal towards the reception input 32. The second switching mode corresponds to the deactivation of the first diode 40 and the activation of the second diode 42. The activated second diode 42 then acts as a short circuit bringing a high impedance to the common point of the switching 22, thus directing the signal from the transmission output channel 34 towards the radiating element 16.

[0087] In an alternative implementation, the diodes 40, 42 of the switch 22 are positioned in series with the reception input 32 and transmission output 34 channels. In another alternative, the diodes are positioned in a mixed series-parallel architecture.

[0088] In an optional embodiment illustrated in Figure 6, an amplification assembly 50 comprising two amplification devices 18 is provided.

[0089] In this example, the transmission input channels 30 of the amplifiers 20 of the two amplification devices 18 are intended to be connected to the same transmitter 12 of a transmission signal Tx. The reception output channels 36 are intended to be connected to separate receivers 14. The other channels are connected to the same radiating element 16.

[0090] Preferably, a phase shifter is added to at least one transmission input channel 30 of one of the amplifiers 20 so as to phase shift the transmission signal Tx arriving on said transmission input channel 30 relative to the transmission input channel 30 of the other amplifier.

[0091] An example of operation of the amplification device 18 will now be described with reference to the examples of FIGS. 3 to 6.

[0092] With reference to Figure 3, when the useful signal is a Tx transmission signal, the amplification device 18 is put into transmission mode, that is to say:

[0093] - the amplifier 20 is voltage-driven with a voltage V HPA so as to operate in active transmission mode (HPA), and

[0094] - the first diode 40 of the switch 22 is activated and the second diode 42 is deactivated, so as to direct the transmission signal 34 towards the radiating element 16. Due to the balanced configuration, the reception output channel 36 is an isolated channel.

[0095] With reference to Figure 4, when the useful signal is a reception signal Rx with an amplitude lower than a predetermined threshold, the amplification device 18 is put into standard reception mode, that is to say:

[0096] - the amplifier 20 is voltage-driven with a voltage V LNA so as to operate in active reception mode (LNA), and

[0097] - the first diode 40 of the switch 22 is deactivated and the diode 42 is activated so as to direct the reception signal coming from the radiating element 16 towards the reception input channel 32. Due to the balanced configuration, the transmission input channel 30 and the output channel 34 are two isolated channels. The reception signal therefore comes out on reception channel 36.

[0098] - In addition, the first diode 40 can constitute the first stage of a limiter function, that is to say it makes it possible to limit the amplitude of the signal (power) when the latter is too high.

[0099] With reference to Figure 5, when the useful signal is a reception signal Rx with an amplitude greater than or equal to a predetermined threshold, the amplification device 18 is put into reception mode without gain, that is to say that:

[0100] - the control voltage of the amplifier 20 is deactivated (OFF mode) so that the amplifier 20 is in inactive mode. In this case, the amplifier 20 acts as a short circuit (mirror) returning the useful signal arriving on its output channel in transmission 34 to its output channel in reception 36. This is for example achieved by changing the polarizations of the transistors of the amplification device 18 so that their outputs appear from an electrical point of view as a short circuit or open circuit at the frequency considered. The useful signal is therefore in this case not amplified by the amplifier 20, and

[0101] - the first diode 40 of the switch 22 is activated and the second diode 42 is deactivated so as to direct the signal coming from the radiating element 16 towards the transmission output 34 and emerging by reflection, and due to the balanced configuration, via the reception output channel 36.

[0102] The operation of the embodiment of figure 6 (two amplification devices 18 connected to the same transmitter 12) is identical to those described in the embodiments of figures 3 to 5. The possible difference resulting in a phase shift and / or a polarization difference applied to the transmission signal Tx for at least one of the channels.

[0103] Thus, the amplification device 18 described is capable of carrying out two types of amplification, high power amplification and low noise amplification, depending on the useful signal to be transmitted / received. The amplifier 20 in balanced architecture associated with a switch 22 makes it a particularly compact device 18 since the amplifier 20 (HPA and LNA) can be integrated on the same active cell. Such an amplification device 18 is, thus, particularly suitable for being integrated into an active antenna, in particular an antenna operating in high frequency bands (Ku for example).

[0104] In addition, the 20 amplifier (HPA and LNA) in balanced architecture allows the improvement of the management of the TOS (abbreviation of Standing Wave Ratio) active in transmission and the improvement of the admissibility in reception. The use for example of a cell in GaN technology for the 20 amplifier allows to have a cell presenting a very strong integration with good electrical performances in HPA and LNA operation (Noise factor, Power, PAE...)

[0105] In the embodiments of Figures 3 to 6, the use of diodes to form the switch 22 makes it possible to reduce losses, compared to a transistor switch. The diode 40 of the switch also makes it possible to carry out the first stage of a limiting function in the standard reception mode (Figure 4).

[0106] As described with the example of Figure 6, it is also easy to adapt this amplification device 18 in a two-channel configuration. Indeed, the minimalist configuration of the amplification device 18 makes it possible to supply the radiating element by two identical channels that can be cut or not, thus making it possible to make vertical (V) or horizontal (H) polarization but also circular by introducing a phase shift between channels. The architecture also makes it possible, for an emission on one or the other polarization (H or V), to receive on the two reception channels at the same time and thus to measure the cross-polarization. The two channels are for example grouped on the same chip in GaN or Silicon type technology.

[0107] Those skilled in the art will understand that the embodiments and variants previously described can be combined with each other provided that they are technically compatible.

Claims

CLAIMS 1. Dual-function amplification device (18) for an active antenna (10), the amplification device (18) comprising: - an amplifier (20) capable of being controlled according to three operating modes among: • an inactive mode, • an active transmission mode in which the amplifier (20) operates as a high-power amplifier, • an active reception mode in which the amplifier (20) operates as a low noise amplifier, the amplifier (20) being configured according to a balanced architecture with two input channels and two output channels among: • a transmission input channel (30) intended to be connected to a transmitter (12) of a transmission signal (Tx), • a reception input channel (32) intended to be connected to a radiating element (16) of an active antenna (10), • a transmission output channel (34) intended to be connected to the same radiating element (16) of the active antenna (10), • a reception output channel (36) intended to be connected to a receiver (14) of a reception signal (Rx), - a switch (22) capable of being controlled between two switching modes so that: • when the amplifier (20) is in the active transmission mode, the switch (22) in the first switch mode, connects the transmission input channel (30) to the transmission output channel (34) of the amplifier (20), and • when the amplifier (20) is in the active reception mode, the switch (22) in the second switch mode, connects the reception input channel (32) to the reception output channel (36) of the amplifier (20).

2. Device (18) according to claim 1, in which the switch (22) is also capable of being controlled so that when the amplifier (20) is in the inactive mode, the switch (22) in the first switch mode, connects the transmit output channel (34) to the receive output channel (36).

3. Device (18) according to claim 1 or 2, in which the amplifier (20) and the switching (22) are capable of being controlled as a function of the useful signal so that: - when the useful signal is a transmission signal (Tx) coming from the transmitter (12), the amplifier (20) is controlled in the active transmission mode and the switch (22) is in the first switch mode, - when the useful signal is a reception signal (Rx) and the amplitude of the useful signal is less than a predetermined threshold, the amplifier (20) is controlled in the active reception mode and the switching (22) is in the second switching mode.

4. Device (18) according to claims 2 and 3, in which the amplifier (20) and the switch (22) are capable of being controlled as a function of the useful signal so that when the useful signal is a reception signal (Rx) and the amplitude of the useful signal is greater than or equal to the predetermined threshold, the amplifier (20) is controlled in the inactive mode and the switch (22) is in the first switch mode.

5. Device (18) according to any one of claims 1 to 4, in which the amplifier (20) is produced on a single active cell.

6. Device (18) according to any one of claims 1 to 5, in which the switch (22) is devoid of transistor switches.

7. Device (18) according to any one of claims 1 to 6, in which the switching (22) comprises diodes whose activation and deactivation allow the transition from the first switching mode to the second switching mode, and vice versa.

8. Device (18) according to claim 7, in which the switch (22) comprises: - a first diode (40) connected in parallel to the reception input channel (32), and - a second diode (42) connected in parallel to the emission output channel (34).

9. Device (18) according to claim 8, in which the useful signal has a useful wavelength, each of the first diode (40) and the second diode (42) being positioned at a distance substantially equal to a quarter of the wavelength of the useful signal relative to the common point of the switch (22) intended to be connected to the radiating element (16).

10. Device (18) according to claim 8 or 9, in which: - the first switching mode corresponds to the activation of the first diode (40) and the deactivation of the second diode (42), and - the second switching mode corresponds to the deactivation of the first diode (40) and the activation of the second diode (42).

11. Device (18) according to any one of claims 1 to 10, in which the amplifier (20) is voltage driven, the amplifier (20) comprising transistors polarized differently between the active mode in transmission and the active mode in reception depending on the driving voltage.

12. Amplification assembly (50) comprising two amplification devices (18) according to any one of claims 1 to 11, the transmission input channels (30) of the amplifiers (20) of the two amplification devices (18) being intended to be connected to the same transmitter (12) of a transmission signal (Tx).

13. Assembly (50) according to claim 12, in which the assembly (50) comprises a phase shifter on the transmission input path (30) of one of the amplifiers (20) so as to phase shift the transmission signal (Tx) arriving on said transmission input path (30) relative to the transmission input path (30) of the other amplifier (20).

14. Active antenna (10), for example for a radar, comprising: - a transmitter (12) of a transmission signal (Tx), - a receiver (14) of a reception signal (Rx), - a radiating element (EM), and - at least one amplification device (18) according to any one of claims 1 to 11 or an assembly (50) according to claim 12 or 13, the transmission input channel(s) (30) of the amplifier(s) (20) being connected to the transmitter (12), the reception output channel(s) (36) of the amplifier(s) (20) being connected to the receiver (14), the transmission output channel(s) (34) and the reception input channel(s) (32) being connected to the radiating element (EM).

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