HK1214413B - Receiver-transmitter - Google Patents

Description

Receiver-transmitter

Technical Field

The present invention relates to Active Phased Array (APA) technology and may find wide application in establishing radar stations and communication systems for moving or stationary targets.

Background

The prior art describes various devices based on APA technology.

Regarding the combination of basic features, the closest to the claimed device is the arrangement of a two-sided phased array according to us patent 3648284a, published 3.7.1972, and which comprises a two-dimensional two-sided phased array comprising a transmit-receive module (TRM) with the ability to steer (communicate) one transmitter and two receivers, radiating and receiving simultaneously in opposite directions, to two radiating elements.

The disadvantages of the technical scheme are that: three dual-sided phased arrays are required to provide look-around, which increases the cost of the radar system; low scanning speed, which causes a wide blind spot in the upper part of the hemisphere; because of the use of a unique phase shifter in the TRM, it is not possible to form completely independent beams in opposite directions, which significantly reduces the energy potential and the capacity for use in radar systems and almost completely hinders their use in communication systems; the inability to use different signal codes in opposite directions reduces the noise immunity in the case of simultaneous transmission and reception; inefficiencies in the communication system due to the use of only two-dimensional arrays; the difficulty of installation and the presence of shadow sectors is caused by the lack of a two-sided array that is offset with respect to each other in the horizontal and/or vertical planes.

Disclosure of Invention

The technical effects obtained by adopting the invention comprise: increased energy potential (energy potential) and efficiency, as well as reduced cost of the radar system or communication system while providing look around, increased scan area in the vertical plane, the ability to form fully independent beams in opposite directions and the absence of shadow sectors.

The technical effects obtained by adopting the invention comprise: the energy potential and efficiency of the receiver-transmitter are increased due to the use of additional phase shifters in the TRM to form at least two independent beams in opposite directions; because only two double-sided APAs are used, the cost of the apparatus is reduced; due to the use of additional single or double sided APAs, or due to the fact that the panels of each side of the double-sided active phased array are mounted to each other at an angle in the vertical plane, any blind viewing areas of the device in the upper hemisphere and/or the lower hemisphere are eliminated; due to the fact that different signal codes are used when the signals are transmitted to different directions, the anti-noise capacity is additionally increased; since the APAs are offset relative to each other in the vertical and/or horizontal planes, APA positioning is facilitated as well as shadow sectors are eliminated.

The above technical effect is obtained by the fact that: in a receiver-transmitter comprising an active two-sided phased array comprising transmit-receive modules, each of which comprises two radiating elements, a transmitter, two receivers, two isolation switches, a mixer and a phase shifter, the two-sided phased array being made one-or two-dimensional, the two-sided phased array being arranged at an angle of 75-105 ° to each other in a horizontal plane while maintaining the ability to look around, the transmit-receive modules being provided with further phase shifters, each of the two phase shifters being permanently connected to one of the receivers or the transmitter via a selector switch and the transmitter being connected to the radiating elements via a selector switch and a circulator, the transmitter being alternately connectable to the radiating elements using different frequencies and/or using different signal encodings, the active double-sided phased arrays are offset relative to each other in the horizontal and/or vertical plane, corresponding to different frequencies and codes of the receiver receive mode that can form at least two independent beams in opposite directions.

The above technical effect is also obtained by the fact that: the panels on each side of the active two-sided phased array can be arranged at an angle to each other in a vertical plane. Furthermore, the receiver-transmitter may additionally be provided with at least one radar or communication station located above and/or below the receiver-transmitter, capable of scanning in two planes to radiate upwards and/or downwards. In this example, the radar or communication station may be made as a two-dimensional active single-sided phased array, or a two-dimensional active double-sided phased array with the transmit-receive module described in claim 1 and with displacements in the horizontal and vertical planes with respect to the receiver-transmitter.

Drawings

The gist of the present invention is illustrated by the accompanying drawings, in which:

fig. 1 schematically illustrates a TRM from the closest prior art U.S. patent 3648284;

fig. 2 shows a general view of the claimed TRM configuration with two radiating elements with selector switches for the transmit channels, with two separate receivers and two separate phase shifters, where 1 denotes the TRM, 2 denotes the selector switch, 3 denotes the radiating element, 4 denotes the receiver, 5 denotes the transmitter, 7 denotes the circulator, 8 denotes the receive-transmit switch, and 9 denotes the phase shifter;

fig. 3 shows a general view of two one-dimensional APAs providing a 360 ° scan in the horizontal plane, where 1 denotes the TRM, 3 denotes the radiating element, 6 denotes the APA panel, 11 denotes the housing;

fig. 4 shows a general view of two-dimensional APAs providing an omni-directional 360 ° scan in the horizontal plane and a ± 45-60 ° scan in the vertical plane, where 1 denotes the TRM, 3 denotes the radiating element, 6 denotes the APA panel, and 11 denotes the housing;

fig. 5 shows a general view of two-dimensional APAs with panels arranged at an angle, providing a 360 ° scan in the horizontal plane and up to 90 ° scan from the horizontal in the vertical plane, where 1 denotes TRM, 3 denotes radiating element, 6 denotes APA panel, 11 denotes housing;

fig. 6 shows an overall view of a device with an additional two-dimensional single-sided APA with a conventional TRM, arranged to radiate upwards, where 1 denotes the TRM, 3 denotes the radiating element, 6 denotes the APA panel, and 11 denotes the housing;

fig. 7 shows a general view of an arrangement with one further two-dimensional APA with a TRM with a transmit channel switch, two separate receivers and two separate phase shifters, and arranged offset with respect to the receiver-transmitter and radiating up and down, where 1 denotes TRM, 3 denotes radiating element, 6 denotes APA panel, 11 denotes housing;

fig. 8 shows an example of a general view of a receiver-transmitter for a radar-communication vessel mast.

Detailed Description

In recent decades, the use of APAs in radar and communication systems has become very widespread. However, the cost of TRM is still quite high. Meanwhile, the size of the TRM becomes smaller due to modern high frequency integrated circuit technology such as Monolithic Microwave Integrated Circuit (MMIC). The reduced size of the TRM enables an easy construction of the device according to the invention.

When a surround view is required, the traditional approach to building a radar or communication system consists in using four APAs, each of which performs ± 45-60 ° scans in the horizontal and vertical planes. Thus, to provide a relatively narrow pattern, such as 2 ° in any range, each APA will include more than 3000 APAs. In the case of four APAs, more than 12000 APAs are needed to enable the formation of four completely independent beams. Such radars are rather expensive. The device according to the claimed invention, while maintaining its energy potential and four independent beams, enables to reduce the cost of such a radar, since about 80% of the cost is associated with the TRM module and the cost of the additional receivers and phase shifters is not high.

Fig. 1 shows the arrangement disclosed in us patent 3648284, where 10 denotes a transmitter, 12 and 14 are radiating elements, 16 is a selector switch, 18 is a phase shifter, 20 and 28 are mixers, and 24 and 26 are receivers. Compared to a radar system using a single-sided phased array, it can reduce the number of TRMs by a factor of two, but the energy potential will be lower than in the case of two independent single-sided phased arrays. Since only one phase shifter is used for different directions, it will occur that signals with the same phase are transmitted and received, which makes it impossible to form completely independent beams.

Fig. 2 shows an arrangement in which 1 denotes a TRM, 2 a switch, 3 a radiating element, 4a receiver, 5 a transmitter, 7 a circulator, 8 a transmit-receive selector switch, and 9 a phase shifter. This arrangement enables simultaneous transmission and reception, and because two independent phase shifters are used, signals in different directions and with different phases can thus form completely independent beams on opposite APA panels without loss of energy potential.

Fig. 3 shows a radar or communication system comprising two one-dimensional two-sided APAs mounted in an orthogonal manner, which operate in opposite directions and comprise the TRM illustrated in fig. 2. This arrangement enables each array panel to scan + -45-60 deg. with independent electron beams in the horizontal plane in opposite directions while providing a look-around. Arranging 2 two-dimensional APAs in mutually orthogonal planes, with the help of independent beams from each APA panel (fig. 4), achieves a look-around in the horizontal plane and ± 45-60 ° in the vertical plane. This arrangement provides the possibility of looking around while maintaining the energy potential and forming independent beams while using 6000 TRMs instead of 12000 TRMs. To prevent the formation of shadow sectors, one-or two-dimensional double-sided APAs are mounted with some offset relative to each other in the vertical and/or horizontal planes, and mathematical parallax can be taken into account.

If a radar with a conventional look-around APA has 12000 TRMs with 1W of power and a switching time ratio of 10 (10% on-time), its average power will be 1200W. When using the apparatus according to the invention to provide a look around, only 6000 TRMs of 1W are required, but they will operate 20% of the time, the average power of the whole system also being equal to 1000 watts.

In case a TRM with an arrangement according to the invention (fig. 2) is used, the transmit channel also works via selector switches for two radiating elements, the receive independent channel (4) being permanently connected to both radiating elements. In this case, the TRM transmitter (5) will operate with a switching time ratio of 5-10 for each radiating element, i.e. it will operate 20-40% of the time in total. When the transmitter operates for one radiating element, the receiver of this radiating element is blocked with the aid of a circulator (7), while the receiver of the opposite radiating element continues to operate for reception, since it is not disturbed by radiation in the opposite direction. To prevent reflected signals from affecting opposing open receivers, they may be transmitted in different directions at approximately but different frequencies and/or use different encoding of the signals, such as phase shifting the signals.

In the RTM of the prior art, there is only one phase shifter. In the case where such a TRM is used in a phased array that operates simultaneously for reception and transmission, it is almost impossible to form two independent beams because the phase of the transmission signal is the same as that of the reception signal. In this case, beams forming an approximate direction with respect to the perpendicular of the respective panels of radiating elements will be formed for transmission and reception in opposite directions. At the same time, the conventional monitoring of the space takes more time than a TRM using a device according to the invention with two phase shifters. If, for example, a pulse is sent from one panel, the prior art TRM diverts the transmitter to the other panel and the first panel receiver begins to receive the reflected signal. At this point, the transmitter transmits a pulse from the second panel and immediately begins receiving a reflected signal at the second panel. Since there is only one phase shifter, both panels operate with the same phase. After the first panel receives the full signal, it starts waiting because the second panel has not yet fully received the signal because the pulse was sent later and the phase change is prohibited. Only after the signal is completely received at the second panel can the phase be changed and the next pulse sent in the other direction. Considering that modern radars use rather long pulses, the time loss will be important for regular monitoring. Furthermore, modern radar systems with electronic beam scanning are not only used for conventional spatial monitoring. When detecting objects, the beam breaks the regular monitoring and additionally processes these objects. When dangerous objects are present, the working time for them is increased by the regular monitoring time. For the time of operation on a target, a phased array with a TRM with one phase shifter as in the prior art completely loosens its efficiency when operated simultaneously in opposite directions, since there is likely to be no target in the same direction away from the other side of the array. In this case, when the TRM uses the device according to the invention, the opposite panel can continue to perform regular monitoring or work on the target independently of the first panel. This is why the use of a TRM with one phase shifter causes time and energy losses in the case of regular monitoring and additional losses in the operation on the target, which significantly reduces the efficiency of the radar system, especially when there are many targets, although this situation just requires a highly efficient radar.

Phased arrays with TRMs with single phase shifters as in the prior art are inefficient or generally unusable for communication systems. Phased array based communication systems are used to receive and transmit data about a particular target located in a known direction. When working with an object from one side, it is not possible to have another object from the other side in the same direction. In this case the efficiency of the communication system will be very low, since when working on the target from one side, the other side will not work at all. And in case such a system is used as a repeater it will not work at all, since it needs to continuously receive information from an object on one side and immediately send it to another object on the other side. It is highly unlikely that these objects are in the same direction.

When four APAs are used in a conventional radar with look-around, the panels of the separate APAs are typically not mounted vertically, but at an angle to the horizontal. This creates a situation where the field of view of the radar is increased in the vertical plane. When a separate APA panel is mounted at an angle of 30 ° to the horizontal, and when the scan in the vertical plane is ± 45-60 °, the radar has a 75-90 ° field of view in the vertical plane relative to the horizontal, i.e. it covers the entire hemisphere. The prior art provides only a parallel arrangement of the panels in the vertical plane, which is a significant disadvantage of this device, since a large blind field of view of 60-90 ° occurs in the upper and/or lower viewing hemisphere. To compensate for this drawback, the device of the invention for the upper hemisphere can also be made with a separate APA panel, for example at an angle of 30 ° to the horizontal, and in this way the whole field of view in the vertical plane will cover all the upper hemisphere (see fig. 5). In this case, however, some problems related to losses occur in the lower TRM because the distance from the TRM to the radiating element is quite far. Another way to increase the field of view to prevent the above disadvantages is to use additional APAs.

At a positioning angle of 45 ° for a target, the distance to the same target will be about 28km even at a flying height of about 20km, which is not too large. Detection of targets at this or less distance may be provided by a single one-sided two-dimensional APA comprising a conventional TRM with a low total energy potential and mounted on top in such a way that emissions are made in the upper field-of-view sector (see fig. 6). Such an APA requires scanning in two planes within the limits of ± 45-60 °. In this case, the total antenna pattern of such an APA will appear as a portion of a sphere having an aperture angle of 90-120 ° (± 45-60 °), which will enable full monitoring of the entire upper hemisphere with the radar system. Such APAs are installed at the top and bottom as needed to illuminate the entire sphere.

Such a two-dimensional APA may include a significant decrease in distance to the target by a factor of 10 compared to the horizontal in the upper and/or lower field of view sectorsA small number of TRMs, for example 16 × 16 TRMs, gives a total of 256 elements, however the antenna pattern of such an APA would be 8⁰×8⁰This may affect the resolution of the radar system in the upper and/or lower sectors, although the power of such a radar system will be quite sufficient in these sectors. In general, the radar system of the present invention will have 6256 TRMs when using the upper single-sided APA, whereas a radar system with four conventional APAs has 12000 TRMs.

To obtain a spherical field of view, it is also possible to use a single two-dimensional two-sided APA with a TRM provided with a selector switch of the transmitter, two receivers and two phase shifters (mounted in such a way that the transmission is made in the upper and lower field of view sectors and with an offset in the horizontal and vertical planes with respect to the two orthogonal APAs), it being possible to take into account mathematical parallax (see fig. 7). Then, a radar system with a spherical field of view area and an additional two-sided two-dimensional APA of size 16 × 16 TRMs would include 6256 TRMs. Conventional designs of radar systems comprising four APAs and 12000 TRMs arranged at an angle to the horizontal cover the hemisphere and generally do not provide a spherical field of view.

In order to cover large blind areas in the upper and/or lower view sectors of a device with a two-dimensional double-sided APA according to the invention, not only two-dimensional single-sided APAs mounted on the top and/or bottom, or single two-dimensional double-sided APAs with upper and lower view sectors, but also other radar structures that fulfil the same function, such as passive-transfer (past) arrays, structures with mechanical scanning, etc., can be used.

Fig. 8 discloses an example of monitoring an upper view sector by constructing an onboard radar-communication mast using two-sided one-and two-dimensional APAs and a single-sided APA. The shipborne radar-communication mast comprises a transmission line radome (30), a mast (31), a double-sided two-dimensional APA (32) of an S-band radar, a double-sided one-dimensional APA (33) of an S-band radar, a double-sided two-dimensional APA (34) of an X-band radar, a double-sided one-dimensional APA (35) of an X-band communication system and a single-sided two-dimensional APA of the X-band radar so as to monitor an upper view sector (37).

By way of example of an on-board radar-communication mast, it can be readily observed that the installation of two independent radar systems and two independent communication systems of different wavebands provides a full-value look-around of the respective systems without any shaded sectors formed by each other and by the mast, since the two-sided array is offset in the vertical and horizontal planes. Using a structure like a rotating APA or a "Y" shaped structure as described in the prior art for such four systems will only not create shadow sectors in a system mounted on top of the mast. The other three systems will have shadow sectors created by the mast and/or by each other, which significantly affects the efficiency of the radar or communication system. In addition, the maximum scan angle for a structure having a "Y" shape as in the prior art would be 30. With larger scan angles, shadows created by adjacent arrays will appear.

The structure disclosed by the device according to the invention can be used efficiently in sonar where also active phased arrays are used and currently also concerns the number of TRMs reduced by a factor of 2.

Industrial applicability

The apparatus according to the present invention is applicable to radar, communication and sonar systems using APA.

Claims (5)

1. A receiver-transmitter comprising a plurality of active two-sided phased arrays including a plurality of transmit-receive modules, each of the plurality of transmit-receive modules comprising two radiating elements, a transmitter, two receivers, and a phase shifter,

wherein each of the plurality of active double-sided phased arrays is fabricated in one or two dimensions,

the plurality of active double-sided phased arrays are arranged at an angle of 75-105 DEG to each other in a horizontal plane while maintaining the ability to look around,

each of the plurality of transmit-receive modules is provided with a further phase shifter,

each of the two phase shifters is permanently connected to one of the receivers or to the transmitter via a selector switch, and the transmitter is connected to the two radiating elements via a selector switch and a circulator,

corresponding to different frequencies and codes of the receiver reception pattern capable of forming at least two independent beams in opposite directions, the transmitter can be alternately connected to the two radiating elements using different frequencies and/or using different signal codes,

the plurality of active double-sided phased arrays are offset relative to each other in a horizontal and/or vertical plane.

2. The receiver-transmitter of claim 1, wherein the panels on each side of the active two-sided phased array can be arranged at an angle to each other in a vertical plane.

3. Receiver-transmitter according to claim 1, wherein there is additionally provided at least one radar or communication station located above and/or below the receiver-transmitter, enabling scanning in two planes for upward and/or downward radiation.

4. A receiver-transmitter according to claim 3, wherein the radar or communication station is fabricated as a two-dimensional active single-sided phased array.

5. A receiver-transmitter according to claim 3, wherein the radar or communication station is fabricated as a two-dimensional active double-sided phased array with the transmit-receive modules arranged with displacements in the horizontal and vertical planes with respect to the receiver-transmitter.