EP3329550B1 - Transceiver device and associated antenna - Google Patents

Description

The present invention relates to that of transmission / reception devices for antennas, in particular transmission / reception devices suitable for operating in the microwave domain and with power levels compatible with radar or electronic warfare applications.

In a manner known per se, a radar antenna consists of a matrix of transmission / reception means (or elementary antennas) comprising substantially planar radiating elements. Each radiating element is associated with a transmission / reception module (or T / R module for "transmission / reception module" in English). The transmission / reception module is arranged in the volume located just behind the transmission / reception means. In transmission, the transmission / reception module amplifies an excitation signal, preferably microwave, received from a remote signal generation electronics and applies the amplified excitation signal to the transmission / reception means. On reception, the transmission / reception module amplifies a reception signal received from the transmission / reception means and transmits the amplified reception signal to a remote acquisition electronics.

In the present document, the association of a transmission / reception means and a transmission / reception module is referred to as a transmission / reception device.

In radar or electronic warfare applications, there is a need to work with high powers, both in transmission and in reception.

However, the accessible powers are limited by the properties of the technologies implemented for the realization of the transmission / reception module. The MMIC technologies (for "Monolithic Microwave Integrated Circuit" in English, or monolithic microwave integrated circuit) conventionally implemented are characterized by maximum acceptable powers, beyond which it would be desirable to be able to work for the applications mentioned above.

Moreover, the document US 2012/188917 A1 discloses a transmission / reception device comprising an antenna 411 having the shape of a disc. The device comprises several transmit / receive modules respectively coupled to the antenna via baluns, each balun being coupled to the antenna by a pair of lines, the ends of which are connected to excitation points diametrically. opposed to each other. The document US 6009314 A discloses an antenna switch for selectively connecting a pair of differential output signals from an output power amplifier to an unbalanced signal from an antenna when transmitting and selectively connecting an input differential pair of signals from a low noise input amplifier to the unbalanced antenna signal when receiving.

The document US 2014/292595 A1 discloses an antenna device comprising a radiation patch in the form of a flat plate, a first feed point configured in a side region of the radiation patch, and a second feed point configured in another lateral region of the radiation patch. The first feed point and the second feed point are the same distance from a virtual ground plane formed on the radiation patch, out-of-phase feed is provided to the first feed point and the second feed point to form a side radiation pattern, and phase power is supplied to the first feed point and the second feed point to form an end light radiation pattern.

The object of the invention is therefore to remedy this problem.

The subject of the invention is a transmission / reception device and an antenna comprising a plurality of such transmission / reception devices according to the appended claims.

To operate with high powers, the invention uses two transmit / receive modules coupled to two polarization ports, in quadrature with one another, of the same flat radiating element, each of the modules operating at a power nominal compatible with the maximum power acceptable by the technology used to manufacture it.

In transmission, the recombination in space of the pair of elementary waves emitted by the radiating element, each elementary wave being excited independently of one another by each of the transmission / reception modules, leads to a wave total whose power is twice as important (+3 dB) as the power of each elementary wave.

On reception, the incident total wave is broken down into two elementary waves, transmitted to each of the transmission / reception modules. An elementary wave has a power twice lower (-3 dB) than the power of the incident total wave.

The invention and its advantages will be better understood on reading the detailed description which follows of a particular embodiment, given solely by way of non-limiting example, this description being given with reference to the appended drawing, which represents schematically a transmission / reception device according to the invention.

The attached figure schematically represents a transmission / reception device 10, which comprises a transmission / reception means 12 and an electronic circuit 13, integrating a first transmission / reception module 14 and a second transmission / reception module 16 The first and second modules 14 and 16 are respectively connected to the transmission / reception means 12 by a pair of supply lines, 31, 32 and 33, 34 respectively.

The transmission / reception means 12, shown schematically in top view in the figure, is known by the term “patch” antenna. It comprises a radiating element 22, substantially planar, disposed above a layer forming a ground plane, a gap being formed between the radiating element and the layer forming a ground plane. This gap is for example made up of an insulating material or of a dielectric material. Preferably, the radiating element 22 is a plate made of a conductive material. It has for example a square shape. As a variant, the radiating element 22 comprises, in addition to an excitation plate, other metal plates which are superimposed on the excitation plate. Whatever the geometry of the radiating element 22 (square, disc, etc.), it is possible to define a central point C.

The plane of the radiating element 22 is defined by two directions D1 and D2, mutually orthogonal: the first direction D1 connects the midpoints of two opposite sides of the square formed by the radiating element 22; the second direction D2 connects the midpoints of the two other opposite sides of the square formed by the radiating element 22.

In general, the excitation of the radiating element is carried out by coupling with the end of a supply line.

This coupling is for example carried out by electrically connecting the end of the supply line to an excitation point of the radiating element. For example, at the end of the supply line, the excitation current flows to the radiating element, through the insulating material placed between the radiating element and the layer forming the ground plane, for example by means of 'a metallized via making it possible to connect the end of the conductive supply line to a pin located at the rear of the radiating element, to the right of the point to be excited.

As a variant, this coupling is produced by a slot made in the layer forming the ground plane. The end of the feed line is arranged so as to overlap this slot from below, the radiating element being located above the layer forming the ground plane. The point of excitation of the radiating element is then located substantially opposite the center of the slot. In the attached figure, it is such a coupling which is implemented, the slots in the layer forming the ground plane being represented schematically by dotted lines.

Other variants of coupling allowing the excitation of a planar antenna are known: thus the excitation can be carried out on the same plane of the flat radiating element, or "patch", by attacking it directly by a printed line. microstrip or “microstrip”, connected to the edge of the “patch”; Thus again, the excitation can be carried out by coupling by proximity to a “microstrip” line printed at a level situated between the “patch” and the layer forming the ground plane.

The first and second transmission / reception modules 14 and 16 are identical to each other. They are arranged between, on the one hand, an electronic microwave signal generation and a remote acquisition electronics (not shown in the figure), and, on the other hand, the transmission / reception means 12.

Downstream side, that is to say on the side of the transmission / reception means, each module is connected directly to the transmission / reception means 12 by a pair of supply lines and is therefore specific, in transmission, to applying a differential excitation signal and, on reception, acquiring a differential reception signal. A module transmission / reception already operating on differential signals, the fact of connecting it to a load in a differential way avoids having to interpose a component, such as a balun (for "balanced unbalanced transformer") to switch from a differential signal to a common mode signal. However, such an intermediate component degrades the power efficiency. The power efficiency of the device 10 is therefore improved.

The first module 14 is therefore coupled to the transmission / reception means 12 by the supply lines 31 and 32, the free ends of which are respectively coupled to two excitation points P1 and P2 of the radiating element 22. The points P1 and P2 are arranged along the first direction D1, symmetrically on either side of the central point C of the radiating element 22.

Similarly, the second transmission / reception module 16 is coupled to the transmission / reception means 12 by the supply lines 33 and 34, the free ends of which are respectively coupled to two excitation points P3 and P4 of the radiating element 22. The points P3 and P4 are arranged along the second direction D2, symmetrically on either side of the central point C.

The distance between two excitation points P1 and P2 or P3 and P4 is chosen so as to adjust the impedance of the load that constitutes the transmission / reception means 12 connected to the terminals of the corresponding transmission / reception module, 14 or 16. Advantageously, the distance between the excitation points P1 and P2 and that between the points P3 and P4 is identical so that the two modules are connected to a load of the same impedance. This distance is preferably chosen so that the impedance of the transmission / reception means 12 is equal to 50 Ohms. The possibility of choosing the impedance implies that it is not necessary to add to the device 10 a component to adapt, by impedance transformation, the impedance between the transmission / reception modules 14 and 16, of on the one hand, and the transmission / reception means 12, on the other hand. This contributes to improving the power efficiency of the device 10, all of the power at the output of a transmission / reception module being applied to the transmission / reception means.

A transmission / reception module 14, and 16, comprises various conventional functionalities, known to those skilled in the art.

A transmission / reception module thus comprises a transmission channel 110 and a reception channel 120.

In transmission, an excitation signal S _E applied by the electronics for generating a microwave signal at the input of circuit 13 is divided, by a distributor 210, into a first excitation signal applied at the input of the channel. transmission 110 of the first module 14 and a second excitation signal applied to the input of the transmission channel 110 of the second module 16. The first and second excitation signals are identical to each other, possibly except for a relative phase θ.

The transmission channel 110 comprises means for amplifying the excitation signal S _E , in particular a preamplifier 114 and a high power amplifier 116 in radar and electronic warfare applications.

The first and second excitation signals are respectively transmitted to the transmission / reception means 12.

In reception, first and second reception signals, identical to each other, possibly up to a relative phase θ, are applied by the transmission / reception means 12 at the input of the reception channel 120 of the first and second transmission modules 14 and 16, respectively.

The reception channel 120 comprises protection means, such as a limiter 118, and an amplifier means, such as a low noise amplifier 119.

The first and second amplified reception signals are summed by an adder 220 of circuit 13, before the resulting reception signal is transmitted to the remote acquisition electronics.

The first module 14 comprises a switch controlled 124 by a control signal S _C so as to switch the first module 14 either into a transmission operating mode, by connecting the transmission channel 110 to the supply lines 31 and 32, or in receive mode, by connecting the receive channel 120 to the supply lines 31 and 32.

The second module 16 comprises a switch 126 controlled by a control signal S _C so as to switch the second module 16 either into a transmission operating mode, by connecting the transmission channel 110 to the supply lines 33 and 34, or in receive mode, by connecting the receive channel 120 to the supply lines 33 and 34.

The control signal S _C applied to the controlled switch 124 of the first module 14 is also the control signal S _C applied to the controlled switch 126 of the second module 16, so that the first and second modules are synchronized in their mode of operation.

If the device 10 is intended to be integrated into an active antenna, in which the wave emitted by a radiating element is out of phase with the waves emitted by neighboring radiating elements, this in order to orient the wave plane and to offset the antenna, each transmission / reception module integrates a phase shifting means controlled by a phase shift signal S _ϕ . Thus, the first module 14 comprises a first phase shifting means 134 and the second module 16 comprises a second phase shifting means. phase shift 136. Each phase shift means comprises for example an attenuator 131 and a phase shifter 132.

In the device according to the invention, the phase shift means 134 and 136 of the first and second modules 12 and 16 are controlled by the same phase shift signal S _ϕ , so that the first and second modules 14 and 16 operate each time instant by introducing the same phase shift either on the excitation signals S _E of the radiating element 22, or on the reception signals S _R coming from the radiating element 22.

Advantageously, the transmission / reception device 10 comprises an adjustment means 140 making it possible to introduce a relative phase θ between the first and second excitation signals respectively applied at the input of the transmission path 110 of each of the modules d. 'transmission / reception 14 and 16. Consequently, the elementary waves respectively excited by the first and second modules 14 and 16 will be out of phase with one another. By recombination in air of this pair of elementary waves, it is then possible to generate a total wave polarized either in a vertical direction V, when a relative phase of 0 ° is applied between the first and second excitation signals ; in a horizontal direction H, when a relative phase of 180 ° is applied; a left circular polarization, when a relative phase of + 90 ° is applied; and a right circular polarization, when the relative phase is -90 °. The adjustment means 140 adjusts the value of the relative phase θ to be introduced as a function of an adjustment signal S _θ received from the remote electronics.

The control signals S _C , phase shift S _ϕ and adjustment _{signals S θ} are emitted by the remote electronics and applied to input terminals of circuit 13.

The first and second transmission / reception modules 14 and 16 are produced in MMIC technology. Preferably, SiGe technology is used, but GaAn technology could equally well be used. Advantageously, as illustrated in the figure, the first and second transmission / reception modules 14 and 16 are produced on the same substrate so as to constitute a single circuit 13. This variant has a reduced size facilitating the integration of the circuit 13 at the rear of the transmission / reception means 12.

Those skilled in the art will find that the present transmission / reception device has many advantages.

The fact of exciting the radiating element by two excitation signals applied to pairs of excitation points located in quadrature with one another makes it possible to symmetrize the transmission / reception pattern of the antenna.

As indicated above, the power of the emitted or received electromagnetic waves may be greater than the nominal operating power of each module, both in transmission and in reception. The power emitted is twice the nominal power. This is particularly advantageous when the nominal power is close to the maximum power authorized by the technology implemented for the production of the transmission / reception modules. Although at the level of each transmission / reception module, the power remains below the maximum power, the device makes it possible to transmit waves at a higher power.

In reception, the fact of distributing the power of the incident wave between the two transmission / reception modules allows the device to be more robust vis-à-vis external attacks, such as illumination of the antenna by a device carrying out an intentional or unintentional interference.

With the antennas of the state of the art, it is also possible to emit a polarized total wave. Only this total wave is produced by the combination of two elementary waves in linear polarization emitted in orthogonal directions by two neighboring radiating elements. A polarization selection switch is interposed between the transmission / reception module and the radiating element to choose the direction in which the element considered must be excited. The polarization selection switches of two neighboring transmission / reception means are controlled in a suitable manner so that the two elementary waves combine to obtain a total wave having the desired polarization. On the contrary, in the present invention, each radiating element is able to individually generate a polarized total wave. The place of emission of the polarized total wave coincides with the central point C of the radiating element. In addition, the fact of avoiding the use of an additional component such as a polarization selection switch further improves the efficiency of the device according to the invention.

As indicated above, the power efficiency of the device according to the invention is optimized, in particular by the possibility of directly connecting the transmission / reception modules to the transmission / reception means. The losses are therefore reduced.

• possibilité d'émettre deux fois plus de puissance, comme vu précédemment
• meilleur rendement à l'émission et à la réception.

Consequently, for a Radar, its range is improved for the following two reasons:

• possibility of emitting twice as much power, as seen previously
• better output and reception.

In addition, due to the reduced losses, the heating of the antenna is reduced.

Such a device can be used alone or in combination with other identical devices in an antenna.

The device being particularly compact, it can be integrated into an array antenna, preferably with electronic scanning, for example used for on-board radar applications or for electronic warfare applications on the ground. It is then suitable for operating in the microwave range, between 3 and 30 GHz, and with high power.

Claims (11)

1. Transceiver device (10), associating first and second transceiver modules (14, 16) with a transceiver means (12) comprising a radiating element (22) substantially planar and having a central point (C), the transceiver means (12) being a patch antenna,
   each transceiver module being a transceiver module coupled to the transceiver means so as to excite a pair of excitation points (P1, P2; P3, P4) of the radiating element, the excitation points of one pair being arranged symmetrically with respect to the central point of the radiating element,
   the first and second transceiver modules being configured to excite respectively a first pair of excitation points arranged in a first direction (D1) of the radiating element, while a second pair of excitation points is arranged in a second direction (D2) of the radiating element, the first and second directions being mutually orthogonal,
   characterized in that the first and second transceiver modules (14, 16) are realized in a MMIC technology, on the same substrate so as to constitute a unique circuit (13), said circuit (13) being integrated at the rear of the transceiver means (12) of said transceiver device,
   and in that the first and second transceiver modules (14, 16) respectively comprise a controlled switch (124, 126) allowing alternation of the mode of operation of the module in transmission and reception, a common control signal (Sc) being applied to the controlled switches of the first and second transceiver modules (14, 16),
   and in that each of the first and second transceiver modules (14, 16) is coupled directly to the transceiver means by a pair of power supply lines (31, 32; 33, 34), a free end of each line is coupled to an excitation point of the radiating element.
2. Transceiver device according to claim 1, wherein the first and second transceiver modules (14, 16) are coupled to the transceiver means (12) so that the transceiver means constitutes, for each of the first and second transceiver modules, a load of the same impedance.
3. Transceiver device according to any one of the claims 1 to 2, wherein the coupling between the free end of one power supply line and one excitation point of the radiating element is realized by a slot provided in a ground plane layer of the transceiver means, the end of the power supply line being arranged to overlap said slot from below, the radiating element being located above the ground plane layer, the excitation point of the radiating element being located above the ground plane layer, the excitation point of the radiating element being then located substantially opposite a center of said slot.
4. Transceiver device according to any one of the claims 1 to 3, wherein a distance between two excitation points of a pair of excitation points of the radiating element (22) is adapted according to the impedance sought for the load constituted by the transceiver means (12) for the first and second transceiver modules (14, 16).
5. Transceiver device according to any one of the claims 1 to 4, wherein each transceiver module has a transmission channel (110) and a reception channel (120), the transmission channel (110) of each of the first and second transceiver modules (14, 16) comprising means for amplifying an excitation signal (S_E), the reception channel (120) of each of the first and second transceiver modules (14, 16) comprising protection means and an amplification means.
6. Transceiver device according to claim 5, wherein the means for amplifying are constituted by a preamplifier (114) and a high power amplifier (116), the protection means are constituted by a limiter (118), and the amplification means are constituted by a low noise amplifier (119).
7. Transceiver device according to any one of the claims 1 to 6, further comprising means (140) for adjusting a relative phase (θ) between the first and second energizing signals applied by the first and second modules to the transceiver means (12).
8. Transceiver device according to any one of the claims 1 to 7, wherein each of the first and second modules (14, 16) comprises a phase shift means (134, 136), and wherein a phase shift signal (S_ϕ) is applied to the phase shift means of the first and second transceiver modules (14, 16).
9. Antenna comprising a plurality of transceiver device, characterized in that each transceiver device is in accordance with a transceiver device (10) according to any one of claims 1 to 8.
10. Antenna according to claim 9, wherein a transmission channel (110) of each of the first and second transceiver modules (14, 16) of the same transceiver device comprises means for amplifying an excitation signal (S_E), preferably consisting of a preamplifier (114) and a high-power amplifier (116), and wherein a reception channel (120) of each of the first and second transceiver modules (14, 16) of the single transceiver device has protection means, preferably consisting of a limiter (118), and an amplifier means, preferably consisting of a low-noise amplifier (119).
11. Antenna according to according to any one of the claims 9 to 10, wherein the first and second modules (14, 16) of the same transceiver device are located between, on the one hand, a microwave signal generation electronics of the antenna and an acquisition electronics of the antenna, and, on the one hand, the transceiver means (12) of said transceiver device, the microwave signal generation electronics and the acquisition electronics being offset from said transceiver device.

Images