RU2439759C1 - Element of phased antenna array - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: element of a phased antenna array (PAA), operating on waves that are polarised in a circle, comprises a dielectric radiator (1), a radiator's wave guide (2), a matching wave guide (3), a wave guide ferrite phase changer (WFPC) of Faraday type with a magnetic memory, a reflector (11) and a body (13). The phase changer with the purpose to increase efficiency and to reduce control energy is made on the basis of a ferrite rod (5) (FR) with a square shape of cross section, which does not comprise a current-conducting coating of a side surface arranged together with a frame (6) and a winding (7) of magnetisation and a magnetic conductor inside the wave guide, the function of which is carried out by a body (13) of the PAA element. To prevent losses of SHF losses as a result of higher waves excitation in WFPC, the magnetic conductor is made in the form of 12 ferrite brackets (8) that are "П"-shaped and are arranged in a certain manner as 3 brackets on each face of the FR (5). The WFPC reflector (11) is made in the form of a WFPC below cutoff waveguide section shunte at one end and adjacent with its other end to the plane of the FR (5) end.

EFFECT: development of a high-technology small-sized element of PAA with low losses, high efficiency and low control energy, simple to make and assemble, strong and resistant to ambient climate and mechanical impact.

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Description

The invention relates to the field of radio engineering of microwave and EHF ranges, and in particular to structures of elements of phased array antennas (PAR) and can be used in radar systems with wide-angle electric scanning of the antenna beam.

Currently, there is a real need for waveguide ferrite phase shifters (WFFF) and PAR elements based on them with small transverse dimensions for antenna systems with wide-angle electric beam scanning, working on electromagnetic waves that are polarized in a circle. The creation of such PAR elements for the millimeter wave range is especially relevant, where the development of elements with small transverse dimensions, high speed and low power consumption encounters certain technical difficulties.

Known elements of phased array antennas that perform electrical scanning of the beam. Each of them can be made, for example, in the form of series-connected waveguide-dielectric emitter and a reflective waveguide ferrite phase shifter Faraday type with longitudinal magnetization, with magnetic memory operating on waves polarized in a circle.

In particular, the multi-element PAR of the Ka-wave range is known (Denisenko V.V. Dubrov Yu.B., Korchemkin Yu.B., Makota V.A., Nikolaev A.I., Tolkachev A.A., Shitikov A.M. ., Shishlov A.V., Shubov A.T. Multi-element phased array of the Ka-wave range.Antennas, 2005, No. 1 (92), pp. 7-14). For phasing of radiating elements in the PAR, waveguide ferrite phase shifters of the reflective type are used for circularly polarized waves. Each WFWF is made on the basis of a round ferrite rod (FS) with a metallized side surface and one end face, it has several longitudinal magnetization windings of the FS and two magnetic cores.

The known elements of the PAR are inherent in a number of disadvantages. Firstly, there are no integrated elements in this headlamp. The radiating elements are located in the carrier plate common for the PAR, and the WFWF are combined into sublattices of different sizes. The lack of reliable contact between the emitters and phase shifters can lead to a mismatch in the headlamps and an increase in microwave losses. Secondly, the CWFWs have large transverse dimensions, and the antenna array pitch is 1.1λ (λ is the wavelength in free space), which limits the beam scanning sector by angles ± 25 ° from the normal to the PAR opening. Thirdly, the consequences of metallization of FS surfaces are the low speed of the WFWF and the high energy of its control.

Known microwave ferrite phase shifter for phased array reflective type (see patent RU No. 37877, IPC H01Q 21/00, H01P 1/18, published 05/27/2008). The microwave ferrite phase shifter comprises a ferrite insert made of a microwave ferrite material located inside a control coil providing longitudinal magnetization of the ferrite insert, and a step emitter of the electromagnetic wave with free space connected to the ferrite insert. It additionally contains a cylindrical metal flange and two elongated U-shaped magnetic cores made of ferrite material, introduced by legs from two opposite sides into contact with a ferrite insert in the form of a metallized ferrite rod of circular cross section through rectangular windows of the control coil, which has an internal longitudinal opening for placement ferrite rod (FS). FS is metallized on all sides, with the exception of the inlet end fixed in the hole of the metal flange in its rear end part. The emitter-coordinator with the outer space is made of a dielectric material, for example, of quartz, and inserted into the front of the metal flange, inside of which there is a sleeve, for example, of fluoroplastic in the form of a ring worn on a ceramic disk in contact with the emitter-coordinator and the input end face of the FS .

The known element of the PAR is a functionally complete element of the reflective PAR. In it, a sleeve made of fluoroplastic with a ceramic disk is in direct contact with the end face of the ferrite rod and the end of the emitter-coordinator and is connected to them by an adhesive joint. Known element is characterized by higher performance and lower power consumption. However, the known PAR element is not free from disadvantages. These are, first of all, the relatively large transverse dimensions of the element. A plastic frame of the control coil is used as a supporting element, to which all other parts are glued, and the FS is metallized on all sides, except for the input end fixed in the hole of the metal flange. Such a constructive implementation of the phase shifter leads to a decrease in speed and increase control energy.

A known element of the PAR, which coincides with the claimed solution for the largest number of essential features and adopted for the prototype (see patent RU No. 2225741, IPC H01Q 21/00, H01P 1/19, published 05/27/2008). A well-known prototype element contains input and output dielectric emitters and a Faraday-type waveguide ferrite phase shifter. The phase shifter consists of a magnetization winding located inside the magnetic circuit and a FS installed inside it in the form of a regular N-faced prism with the number of faces N≥4. The magnetic core is made in the form of U-shaped staples, one on each face of the ferrite rod. The waveguide of the PAR element is formed by a conductive coating of the FS side surface. There are also two waveguides of emitters, two matching waveguides, the diameter of which is greater than or equal to the diameter of the circle described around the FS cross section, and two short circuits with holes along the axis. Each matching dielectric insert is made in the form of a serial coaxial connection of the washer and the rod mounted along the axis inside the hole in the cylindrical shank of the dielectric emitter, which is made of a material with a dielectric constant ε _and = 3.8-4.2. The PAR element is placed inside the housing, made in the form of a metal sleeve connected to the emitter waveguide by an adhesive joint.

This is a small-sized element of the HEADLAND type through passage, strong and resistant to external influences. Based on it, an element of reflective headlamp (OFAR) can also be built.

The disadvantages of the prototype include low speed and high power consumption due to the presence of a conductive coating on the side surface of the FS. The energy spent on controlling the WFWF is mainly spent on changing the state of the remanent magnetization of the ferrite medium and overcoming the effect of the "closed loop". This coil in VFVF is a waveguide formed by a conductive coating of the side surface of the FS. With a pulsed magnetization reversal of VFFV, conduction currents appear in this coil, which slow down the process of magnetization reversal and increase the energy consumption from the control system of VFFV. The need to solder FS into waveguide reinforcement also complicates the manufacturing process of the PAR element.

The objective of the invention is to ensure the operation of the PAR element in reflective mode, simplification of the PAR element of the design and manufacturing technology, reducing the complexity of production, increasing speed and decreasing control energy.

The solution to this problem is achieved by the fact that the PAR element operating on circularly polarized waves contains a dielectric emitter (DI), an emitter waveguide, a matching waveguide, a casing, and a Faraday wave type VFW with magnetic memory. VFFV consists of a waveguide, a magnetizing winding located inside the magnetic circuit installed inside the FS magnetizing winding with a square cross-sectional shape. A dielectric insert is installed between the first end face of the FS and the end face of the MD in the matching waveguide. The magnetic circuit is made in the form of ferrite staples located on the faces of the FS. Each ferrite bracket contains a plate and two shoes facing soles to the FS edge. The novelty of the PAR element is that it contains a dielectric frame located between the magnetization winding and the side surface of the FS, and a reflector made in the form of a shorted waveguide shorted at one end and adjacent the other end to the second end of the FS. The FS first edge is adjacent directly to the flange of the matching waveguide. As the waveguide WFWF serves the above-mentioned housing. On each face of the FS there are three ferrite staples close to each other, the shoes of which are in direct contact with the ferrite of the FS. Each ferrite bracket is made of a width a _cc ≤0.33 a _c , where a _c is the size of the FS cross section, mm. The average staples on two adjacent faces of the FS are offset relative to their extreme brackets along the longitudinal axis of the plate in different directions by the thickness of the shoe, and the length ℓ _St FS, the length ℓ _SK ferrite staples and the thickness t _{b of the} shoe satisfy the relation:

ℓ _st = ℓ _ck + t _b , mm.

The radiator waveguide, the matching waveguide and the body of the PAR element can be made in the form of a single waveguide.

The body of the headlamp element and the reflector VFFF can be made in the form of a single waveguide.

The material of ferrite staples and the material FS in the particular case has the same magnetic parameters, and the thickness t _{b of the} shoes of ferrite staples can satisfy the ratio

0.25a _s <t _b <0.3a _s .

The dielectric frame can be made of a material with a relative dielectric constant of not more than 2.5, and the thickness of the walls of the frame can be at least 0.1λ, where λ is the wavelength in free space, mm

The reflector can be formed as a circular waveguide length at least 0,2λ _Neg diameter D satisfying the relation

0,4λ <D _Neg ≤0,5λ.

To increase the speed and reduce the control energy in VFVF FS is used without a conductive coating of its side surface and one of the ends.

Simplification of the design, improving manufacturability and reducing the complexity of the production of the PAR element is achieved by eliminating the technological operations necessary for the manufacture of the prototype, such as multilayer metallization of the surface of the FS by vacuum deposition or chemical deposition and the precision soldering or gluing of the FS into the waveguide armature. Achieving the same goals is also the use of FS with a square cross-sectional shape and shoes of ferrite staples, excluding diamond grinding of complex landing surfaces.

To ensure the operation of the PAR element in the reflective mode, an electromagnetic wave reflector is installed at the output of the VFFV.

The presence of distinctive features allows us to conclude that the proposed technical solution meets the criterion of novelty.

The invention is illustrated by drawings, where:

figure 1 shows a longitudinal section of the inventive element HEADLIGHTS;

figure 2 shows a cross section at the location of the shoes of the ferrite staples along AA of the PAR element shown in figure 1;

figure 3 shows a cross section at the location of the frame and the magnetization winding and the shelves of ferrite staples along BB of the element HEADLIGHT, shown in figure 1;

figure 4 shows a cross section at the location of the reflector in BB of the headlamp element shown in figure 1;

figure 5 shows a perspective view of a ferrite block VFFV element PAR.

Figure 1-5 indicates: 1 - DI, 2 - emitter waveguide, 3 - matching waveguide, 4 - dielectric insert, 5 - FS, 6 - magnetization coil frame, 7 - magnetization winding, 8 - ferrite bracket, 9 - shelf ferrite staples, 10 - shoe ferrite staples, 11 - reflector, 12 - conclusions of the magnetization winding, 13 - housing of the PAR element, 14 - cheeks of the magnetization winding frame.

The PAR element works as follows.

When it falls onto a headlamp (not shown in the drawing), composed of the claimed elements of the headlamp, an electromagnetic wave polarized in a circle from the illuminator of the headlamp (not shown) or from free space, an electromagnetic wave arrives at the input of the waveguide 2 DI 1, for example round the wave received by CI 1. In the waveguide 2 of the emitter 1, a wave of type H _{11 is} excited, from its output it goes to the input of the matching waveguide 3 with a dielectric insert 4 and also excites a wave of type H _{11 in it} . From the output of the matching waveguide 3, the electromagnetic wave enters the VFFV element of the PAR, which includes the housing 13 of the PAR element, which acts as a waveguide of the VFFV, FS 5, frame 6 with magnetization winding 7 with leads 12 and a magnetic circuit in the form of 12 ferrite staples 8. Excited in FS 5 a surface wave propagates along it, reaches the end face of FS 5, is reflected from the input of the reflector 11, propagates in the opposite direction, sequentially passes FS 5, matching waveguide 3, waveguide 2 of radiator 1, and DI 1 is emitted into free space. The phase of the re-emitted element of the PHAR of an electromagnetic wave polarized in a circle depends on the wavelength λ, the cross-sectional shape and dimensions of DI 1, waveguides 2 and 3, FS 5, frame 6, magnetization winding 7, ferrite brackets 8 and reflector 11, as well as parameters of materials DI 1, dielectric insert 4 and FS 5.

An additional phase change of the re-radiated electromagnetic wave, for example, within the range of Δφ = 0 ° -360 °, is discretely or continuously carried out by means of the WFFW by changing the parameters of the FS 5 ferrite media and ferrite brackets 8 (for example, residual magnetic induction Br). A longitudinal magnetization field is created in FS 5 by a magnetization winding 7 fed through the terminals 12 of the magnetization winding 7 from a beam control system HEADLIGHT or from a power source (not shown in the drawings).

The location of the ferrite block (Fig. 5) inside the waveguide, the function of which in the inventive element of the PAR is the housing 13 of the PAR element, makes this waveguide a multiwave. In this case, the presence of ferrite brackets 8 adjoining the shoes 10 to the side surface of the FS 5, which does not have a conductive coating, the frame 6, and the magnetization winding 7 can lead to the excitation of the waves of higher types of the multiwave waveguide WFWF and increase the reflection of the surface wave FS 5 from its junction with matching waveguide 3. The consequence of this may be an increase in microwave losses introduced by the WFWF. To prevent an increase in microwave loss, the relative dielectric constant of FS 5 and the dimensions of its cross section a _c × a _c are chosen such that the field of the lowest surface electromagnetic wave of FS 5 is mainly concentrated within the area of S _st = a _c ^{2 of the} cross section of FS 5. V In this case, at the junction of the FS 5 and the matching waveguide 3, a surface FS 5 wave is excited with minimal excitation losses of higher types. Moreover, on each face of FS 5 there are three ferrite brackets 8 close to each other, shoes 10 of which are in direct contact with ferrite FS. Each ferrite bracket 8 is made of a width a _ck ≤0.33 a _s . The middle brackets (8b in FIG. 5) on two adjacent faces of FS 5 are offset relative to their extreme brackets (8a, 8c) along the longitudinal axis of the shelf in different directions by a thickness t _{b of} shoe 10.

For the same purpose, the reflector 11 VFFF made in the form of a segment of the transcendental waveguide, for example round. Its diameter D _sp and length ℓ _sp are selected from the condition of minimizing the losses of the WFWF to the excitation of waves of higher types.

The dimensions of DI are 1 D _and and ℓ _and are selected from the condition of matching the PAR element with free space or with the waveguide of the measuring path.

In order to weaken the influence of the magnetization winding on the propagation of a surface wave along the FS, the magnetization winding 7 is separated from the surface of the FS 5 by a frame 6.

The proposed PAR element is characterized by the simplicity of manufacturing individual parts and blocks and the assembly of the device as a whole. In its manufacture can be used normalized, commercially available materials, adhesives and processes. The waveguide 2 of the emitter 1, the matching waveguide 3, the housing 13 of the PAR element and the reflector 11 are bodies of revolution that can be easily manufactured on high-performance equipment. Moreover, to reduce the complexity of manufacturing an element of the PAR, the radiator waveguide 2, the matching waveguide 3 and the housing 13 can be made in the form of a single waveguide. Or, in the form of a single waveguide, a housing 13 and a reflector 11 can be manufactured.

DI 1 can be made, for example, of a composite material (microwave ferrites and dielectrics / Prospect. - St. Petersburg: OJSC Magneton Plant, 2001. - 20 p.) With a relative dielectric constant ε _and = 3.8-4.2 and made by casting, pressing or machining. Similarly from casting, pressing or machining. Similarly, composite materials (microwave ferrites and dielectrics / Prospect. - St. Petersburg: OJSC Magneton Plant, 2001. - 20 p.) Can be made of a dielectric insert 4 and a frame 6 of the magnetization winding 7.

For the manufacture of FS 5 and ferrite staples 8, normalized ferrite materials can be used (microwave ferrites and dielectrics / Prospect. - St. Petersburg: OJSC Magneton Plant, 2001. - 20 p.), For example, ferrite grade 1SCh12. The simplicity of the shape and seating surfaces of these parts makes it possible to use the widely used flat diamond grinding process in their manufacture.

The assembly of the inventive PAR element is advisable to carry out by gluing the individual parts using normalized adhesives. In particular, for the adhesive bonding of the waveguide 2 of the emitter 1 and the matching waveguide 3, the matching waveguide 3 and the casing 13, as well as the casing 13 and the reflector 11, in the case of their manufacture as separate parts, an EC-S conductive adhesive used in installation operations in the manufacture of electronic products and withstanding thermal cycling in the temperature range from -60 to + 85 ° C.

To assemble the inventive element PAR, there is no need to develop special conductors and devices. All parts, with the exception of the ferrite block — bodies of revolution and their axial centering — are ensured by the selection of tolerances on the dimensions of the parts during their manufacture. The ferrite block shown in Fig. 5, when installed in the housing 13 of the PAR element, is centered using the cheeks 14 of the frame 6 of the magnetization winding 7. To increase the resistance of the PAR element to weathering, in addition to the adhesive joints of the individual parts of DI 1, the dielectric insert 4 and the ferrite block (Fig. 5) can be coated with a moisture-resistant varnish. To seal the device, the openings for the conclusions 12 of the magnetization winding 7 can be filled with sealant.

With the claimed structural embodiment, the PAR element is a solid and rigid structure, resistant to external shock and vibration mechanical stresses. The proposed PAR element is structurally simple, technologically advanced, its manufacture is characterized by low labor intensity and low cost. To create it in the conditions of mass production, there is no need to develop complex technological devices and use expensive technological processes characteristic for the manufacture of the headlamp element adopted as a prototype.

Thus, the practical implementation of the proposed PAR element is not in doubt.

The proposed PAR element can be used as part of a multi-element phased antenna array, the conclusions of its magnetization winding are connected to the beam control system of the PAR (not shown).

The technical result consists in creating a high-tech small-sized element of the PAR, with low losses, high speed and low control energy, easy to manufacture and assemble, durable and resistant to external climatic and mechanical influences.

The effectiveness of the proposed technical solution was tested experimentally when creating elements of the phased array of the millimeter wave range in the frequency band of a rectangular waveguide with a cross section of 7.2 × 3.4 mm ² . The experimental sample of the PAR element has a diameter D _{e of} not more than 0.68λ, which allows it to be used to create flat reflective PARs with wide-angle electric scanning of the beam when it deviates from the normal to the opening of the PAR until 45 ° -50 °.

The phase shifter of the PAR element creates an adjustable phase shift Δφ = 0 ° -400 °, the maximum losses introduced by it do not exceed 1.5 dB, while the maximum rephasing time is not more than 20 μs, and the average control energy does not exceed 15 μJ.

Claims (6)

1. The element of the phased antenna array (PAR) operating on circularly polarized waves, comprising a dielectric emitter (DI), an emitter waveguide, a matching waveguide, a housing and a Faraday-type waveguide ferrite phase shifter (VFFV) with magnetic memory, consisting of a waveguide, a winding of magnetization located inside the magnetic circuit installed inside the magnetization winding of a ferrite rod (FS) with a square cross-sectional shape, between the first end of which and the end of the MD in the matching waveguide a dielectric insert is mounted, and the magnetic circuit is made in the form of ferrite staples located on the faces of the FS, with each ferrite bracket containing a shelf and two shoes facing soles to the face of the FS, characterized in that it contains a dielectric frame located between the magnetization winding and the side surface of the FS , and a reflector made in the form of a shorted-off waveguide shorted at one end and adjacent the other end to the second end of the FS; which the first end adjoins directly to the flange of the matching waveguide, said body is used as the waveguide WFFW; on each face of the FS there are three ferrite staples close to each other, the shoes of which are in direct contact with the ferrite of the FS; each ferrite bracket is made of a width a _ck <0.33a _s , where a _c is the size of the FS cross section, mm; while the average staples on two adjacent faces of the FS are offset relative to their extreme brackets along the longitudinal axis of the shelf in different directions by the thickness of the shoe, and the length ℓ _St FS, the length ℓ _SK ferrite staples and the thickness t _{b of the} shoe satisfy the relation:
ℓ _st = ℓ _ck + t _b , mm. 2. The element according to claim 1, characterized in that the emitter waveguide, the matching waveguide and said body are made in the form of a single waveguide. 3. The element according to claim 1, characterized in that the said housing and reflector are made in the form of a single waveguide. 4. The element according to claim 1, characterized in that the material of the ferrite staples and the material FS has the same magnetic parameters, and the thickness t _{b of the} shoes of the ferrite staples satisfies the ratio:
0.25a _s <t _b <0.3a _s . 5. The element according to claim 1, characterized in that the dielectric frame is made of a material with a relative dielectric constant of not more than 2.5, and the wall thickness of the frame is not less than 0.1λ, where λ is the wavelength in free space, mm 6. An element according to claim 1, characterized in that the reflector is formed as a circular waveguide length at least 0,2λ _Neg diameter D satisfying the relationship:
0,4λ <D _neg <0,5λ.

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