RU2060572C1 - Waveguide power system of phased antenna array - Google Patents

Abstract

FIELD: microwave devices, radio equipment. SUBSTANCE: device has input power splitter connected to axis-symmetrical multichannel power splitter and section of ladder-type power splitters. Input power splitter uses herringbone splitting circuit set up of waveguides T-junctions. Axis-symmetrical multichannel power splitter is made as transition from rectangular H₁₀- wave guides to coaxial H₀₁.-wave guide. Each ladder-type power splitter in section of ladder-type power splitters uses herringbone type circuit arrangement set up of rectangular waveguides. Input rectangular waveguides are arranged over circumference and connected to output rectangular waveguides of axis-symmetrical multichannel power splitter. Input power splitter is placed inside axis-symmetrical multichannel power splitter which is installed in section of ladder-type power splitters. Section of ladder-type power splitters may be assembled of wedges with grooves on side edges. Output waveguides of axis-symmetrical power splitter may have different sectional areas. EFFECT: enlarged functional capabilities. 5 cl, 10 dwg

Description

 The invention relates to radio engineering, specifically to waveguide paths of antenna arrays, waveguide dividers, waveguide combiners, and can be used in radars, space radio communications equipment and other microwave equipment that require the division of power from one or more sources into a large number of channels.

 In radar and in space radio communications, phased antenna arrays (PAR) with two-dimensional scanning are used, operating on radiation and on reception. The requirements for broadband, small losses of microwave energy, and the provision of a given amplitude distribution in the aperture of the HEADLIGHTS are imposed on the power supply (excitation) systems of the PAR. When working on radiation, the most favorable is a uniform distribution, in which the loss of energy dissipation is minimal. The design of the power supply system should have minimum longitudinal dimensions (in the direction perpendicular to the opening of the PAR) and provide good heat removal from the phase shifters of the PAR, emitted by the control currents and due to active losses of microwave energy.

 In the short-wave part of the microwave range for centimeter and millimeter waves with a high level of radiated power, waveguide power systems are used along with spatial excitation systems.

 The aim of the invention is the creation of a waveguide power supply system for a flat headlamp with the number of elements from several hundred to one and a half thousand. PAR elements can be distributed along the opening unequally, but approximately uniformly, to provide a sufficiently high coefficient of surface utilization. The waveguide system should have low losses and broadband. Its longitudinal dimension should be small, and its design should provide good heat dissipation from the PAR elements. The waveguide system should not contain elements that reduce its electrical strength.

 These requirements are met by the proposed waveguide parallel power supply system for a phased array antenna, consisting of an input divider, an axisymmetric multi-channel divider, connecting waveguides and a set of multi-link dividers constructed according to a Christmas tree scheme.

 The axisymmetric multi-channel divider has a central hole. An inlet divider consisting of several waveguide double tees is placed in this hole. An axisymmetric divider is located in the inner hole of a multifaceted truncated pyramid composed of radial wedges. On the adjacent lateral faces of these wedges, multi-link dividers are made, consisting of E-tees connected according to a "Christmas tree" scheme. The end faces of the wedges form planes parallel to the opening of the PAR.

(i 1), где i 1, 2,m номер входа, а m число входов. Фазирование входов осуществляется с помощью волноводных скруток на 90^о и на 45^о, установленных между волноводными двойными тройниками во входном делителе и развернутых попарно в противоположные стороны.The axisymmetric multichannel divider is made according to the scheme of direct conversion of a wave of type H ₀₁ in a coaxial into waves of type H ₁₀ in rectangular waveguides. An axisymmetric multi-channel divider from several inputs phased by law is excited

(i 1), where i 1, 2, m is the input number, and m is the number of inputs. Phasing inputs performed via waveguide twists and ^about 90 to ^about 45, mounted between dual waveguide tees in the input divider and deployed in pairs in opposite directions.

 The axisymmetric multichannel divider provides for the possibility of uneven division of microwave energy. In this case, multi-link dividers with a large number of division are connected to the outputs of an axisymmetric multi-channel divider having a higher level of microwave energy. This ensures uniform excitation of the PAR elements with dense filling of the aperture.

 A denser arrangement of the outputs of the waveguide parallel power system in the PAR openings is also achieved by displacing grooves on opposite side faces of the radial wedges, which form multi-link dividers.

 Known waveguide power systems built in serial or series-parallel circuits. Such systems include, for example, a waveguide power system (US patent N 4952894, 08/28/1990). The advantages of this system are a small longitudinal dimension and the possibility of its use in an antenna array with a large number of elements. However, this system has the disadvantages inherent in all series power circuits: a limited power level due to the limited electric strength of the communication elements and the limited operating frequency band due to different electric lengths of electromagnetic energy paths from a common source to different radiators of the antenna array.

Known waveguide parallel power systems in the form of multi-link power dividers 1: 2 ^k , (k 1, 2, 3.) containing waveguide tees and connecting waveguides of various designs.

 Known waveguide power divider for a phased antenna array (ed. St. USSR N 1406674 class. H 01 P 5/12, 07/07/1986) with a reduced longitudinal dimension. However, the use of such a divider in a headlamp with a number of elements of the order of 1000 will require about 10 cascades of division (k ≈ 10). In this case, the axial (longitudinal) dimension will be larger than the aperture diameter and the power system will introduce noticeable losses.

 Known multi-channel power dividers based on E-sector waveguide junctions (US patent N 3500422, 11/08/1960, ed. St. USSR N 1394283, 05/07/1986) with a large number of PAR elements will have an even larger longitudinal dimension.

Known waveguide multi-channel power dividers (adders) with axial symmetry. In some, a circular waveguide in which the H wave is excited $\genfrac{}{}{0ex}{}{\text{o}}{\text{01}}$ , excites a set of rectangular waveguides located in a circle. This type of divider has a very limited number of division channels. In others, a radial waveguide is used, excited in the center by a round or coaxial waveguide and having a set of waveguide outputs at the periphery (US patent N 4926145, CL N 01 P 5/12, 05/15/90). In this type of axisymmetric divider, the number of channels can be quite large. However, the location of the waveguide outputs of the divider on a circle makes it difficult to excite the PAR elements located on a flat aperture more or less uniformly.

 The literature indicates the possibility of creating a parallel combined power sharing scheme consisting of an axisymmetric divider with a radial waveguide, the outputs of which are connected to the PAR elements with flexible cables (Antennas and microwave devices. Designing phased antenna arrays /. Ed. By D. I. Voskresensky. M . 1981).

 The aim of the invention is the creation of a parallel waveguide combined power supply system for a flat headlamp with a number of elements of about 1000, having a small longitudinal dimension, low losses and providing radiation with a high power level.

 The invention solves the problem of creating a headlamp with a flat opening and a small longitudinal dimension with a high level of radiated power. At the same time, such important characteristics of the headlamps as broadband, wide-angle scanning with small losses in the power system are retained. The problem is solved by using a parallel waveguide power system, which is a compact metal structure in the form of a multifaceted truncated pyramid with a central hole, in which an axisymmetric multichannel waveguide divider of cylindrical shape, also having a central hole in which the waveguide input divider 1: m is installed, where m is the number inputs of an axisymmetric multi-channel divider.

A multifaceted truncated pyramid is formed of radial wedges, the number of which is equal to the number of outputs of the axisymmetric divider. On the adjacent lateral faces of the radial wedges, waveguide channels are made that form multi-link dividers 1: 2 ^k , k 2,3,4, and these dividers can have a different number of k links. The wedges are interconnected in the middle of the wide walls of the waveguide channels. The inputs of multi-link dividers are connected to the outputs of an axisymmetric divider using connecting waveguides. The outputs of the multi-link dividers are located on the plane of the base of the polyhedral truncated pyramid, parallel to the aperture plane of the PAR. They are connected to the output waveguide channels containing elements aligning the phase and polarization of electromagnetic waves. This function can be performed by PAR elements.

 The outputs of the waveguide parallel power system are located in the aperture of the HEADLAND along a radial-ring grid. In this case, the number of PAR elements is 1.5.2 times less than if the same elements are placed on a hexagonal grid, which usually takes place in a PAR with spatial excitation. However, since the radial-annular arrangement is non-equidistant, a decrease in the number of elements does not lead to the appearance of secondary maxima when scanning the beam. A certain decrease in the gain of the PAR due to a decrease in the number of elements is compensated by a significant reduction in energy dissipation compared with spatial excitation.

 The implementation of the waveguide system in the form of a single metal structure adjacent to the opening of the PAR, provides good heat dissipation from the PAR elements.

 In FIG. 1 shows a waveguide parallel power system for a phased array antenna, a general view in partial section; in FIG. 2 input divider, axisymmetric multi-channel divider and section of connecting waveguides, general view with a partial section; in FIG. 3 cross-sections A-A, B-B, B-B, G-D in FIG. 2; in FIG. 4 is a cross-sectional view of FJ in FIG. 2; in FIG. 5 is a right view of the inner part of the toroidal section of an axisymmetric multi-channel divider (see Fig. 2) with a diametrical section; in FIG. 6 is a left view of the outer part of the toroidal section of an axisymmetric multi-channel divider (see Fig. 2) with a diametrical section; in FIG. 7 is a left view of a section of multi-link dividers (see Fig. 1); in FIG. 8 radial wedge sections of multi-link dividers with projections of two sides; in FIG. 9 double tees of multi-link dividers; in FIG. 10 cross sections of double tees (see FIG. 9).

The waveguide parallel power supply system of the HEADLIGHT consists of the following parts (see Fig. 1): input divider 15 (for example 1: 4); axisymmetric multi-channel divider (16) (for example, 4:72); section 17 of connecting waveguides, waveguide twists per example ^90; sections 18 of multi-link power dividers, for example 1:16 and 1: 8.

 The longitudinal dimensions of the waveguide parallel power system are determined by the axial size of the axisymmetric multi-channel divider 16. The remaining components are either located inside it (input divider 15) or surround it (section of the connecting waveguides 17 and section of the multi-link dividers 18.

 Such a construction achieves high compactness of the waveguide parallel power system.

 In FIG. 2 shows an input splitter 15, an axisymmetric multi-channel splitter 16, and a section of connecting waveguides 17.

The principle of operation of the axisymmetric multi-channel splitter 16 is to convert waves of type H ₁₀ in m rectangular input channels (for example, m 4) to a wave of type H ₀₁ in a coaxial waveguide having a large diameter, followed by conversion of a wave of type H ₀₁ into waves of type H ₁₀ in n output channels of rectangular cross-section (for example, n 72). In FIG. 2 shows 4 input waveguides of standard rectangular cross-section a x b, curved in the H-plane by 180 ^° 31, coaxial waveguide 32 and toroidal section 34.

In FIG. 3 shows sections of a coaxial waveguide by planes AA, BB, BB, GG, DD, shown in FIG. 2. In section A-A, input channels of rectangular section 35 are visible. In sections B-B, B-B, G-D, a gradual expansion of the waveguide channels is shown until they completely fill the entire space between the outer 37 and inner 38 cylindrical surfaces of the coaxial waveguide. As soon as the width of the waveguide channels in the azimuthal direction becomes more critical for the higher type of wave, the channels are separated by radial metal partitions 36. In this example, the number of partitions reaches 24. In the G-D section, the partitions end and a type H wave is formed in the coaxial waveguide $\genfrac{}{}{0ex}{}{\text{to}}{\text{01}}$ . To filter other types of waves having longitudinal currents on the conductors of a coaxial waveguide, a filter 33 is installed. The filter is a set of alternating rings of metal and absorbing material (for example, ferroepoxide). Loss of wave type H ₀₁ in a coaxial that does not have longitudinal currents in such a filter is negligible. In the coaxial waveguide 32, the inner surface of the outer conductor is conical. This makes it possible to reduce the cross section of rectangular waveguides at the output of an axisymmetric multichannel divider. This decrease allows you to increase the number of output channels of the waveguide parallel power supply system PAR. In addition, this design allows to simplify the manufacturing technology of a coaxial waveguide.

A distinctive feature of the axisymmetric multi-channel splitter 16 is the absence of a round or radial waveguide in its composition. The presence of a circular waveguide with wave H $\genfrac{}{}{0ex}{}{\text{o}}{\text{01}}$ limits the number n of output channels and increases the longitudinal size. In the presence of a radial waveguide, problems arise with the transmission of a high power level and with the matching of radial and coaxial waveguides. Direct transition from a coaxial waveguide of large diameter to a wave of type H $\genfrac{}{}{0ex}{}{\text{k}}{\text{01}}$ and n to rectangular waveguides makes it possible to divide by a large number n (in this example, n 72) at a high power level. There is also the possibility of uneven division, which is essential for the further construction of a parallel waveguide power supply system for the PAR.

In FIG. 4 is a left view of a toroidal section 34 of an axisymmetric multi-channel divider. In the toroidal section there are waveguide channels of rectangular cross section of two types: the first have at the input a cross section a ₁ x b ₁ (37), and the second a ₁ x b _1/2 (38), and ₁ ; a; b ₁ ≅ b, where a x b is the standard section of a rectangular waveguide for a given frequency range. In this example, 24 channels have a ₁ x b ₁ section at the input and 48 channels have a ₁ x b _1/2 section. At the output, all channels have a cross section a ₁ x b ₁ .

 The toroidal section consists of two parts 40 and 41, each of which has the shape of a half circular torus, cut in diameter.

In FIG. 5 shows a right view of the inner part 40 and its diametrical section, and FIG. 6 is a left view and a diametrical section of the outer part 41. In FIG. 5 and 6, grooves of constant (42) and (44) and variable (43) and (45) sections are visible. When connecting parts 40 and 41, these grooves form waveguide channels of constant and variable cross-section, cut on a neutral midline. At the output of the toroidal section, all waveguide channels have the same cross section a ₁ x b ₁ , but twice as much power passes through a channel that has a constant cross section (46) than through one that has a variable cross section (47). Thanks to such a device of the toroidal section 34 at the outputs of an axisymmetric multi-channel divider, we obtain the desired power distribution. The input divider 16 shown in FIG. 2, performs the division of the microwave energy from the common entrance to the m inputs of the axisymmetric multi-channel divider 16, m in the example 4. The input divider consists of double tee waveguide 21, waveguide 90 twists ^of the right 22 and left 23, the rotation of waveguide 45 twists ^about right (24) and left (25) rotation. Cross sections of the input divider elements are shown in FIG. 3.

For excitation in a coaxial waveguide type H waves $\genfrac{}{}{0ex}{}{\text{to}}{\text{01}}$ it is necessary that the phase of electromagnetic waves at each input of the axisymmetric multi-channel divider 35 (see Fig. 3) be i-1 / m 360 ^о , where i is the input number (i 1,2, m). In this example, m 4 and the phase of the i-th input should be equal to (i-1) 90 ^about . This is achieved by the presence in an input waveguide splitter ⁹⁰ twists per (22), (23) and ^about 45 (24), (25), deployed in pairs in different directions. The directions of the vectors of the electric field E in the sections of the elements of the input divider and at the inputs of the axisymmetric multichannel divider are shown in FIG. 3.

The connecting waveguide section 17 shown in FIG. 2, connects the outputs of an axisymmetric multi-channel divider with the inputs of multi-link dividers. Connecting waveguides are, for example, ^about 90 twists (50).

, в данном примере Φ 5^о. Имеются разные типоразмеры клиньев в зависимости от типа многозвенных делителей на их боковых гранях и от их положения относительно периметра раскрыва. В данном примере 12 типоразмеров. На фиг. 7 позиция 62 обозначает один из типоразмеров клина.In FIG. 7 shows a section of multi-link power dividers. The shape of the perimeter of section 61 corresponds to the shape of the perimeter of the HEADLIGHTS, for example a hexagon. The section is assembled from radial wedges, the number of which n is equal to the number of outputs of the axisymmetric multi-channel divider, in this example n 72. Grooves 63 are made on the contacting faces of the wedges, forming rectangular waveguides a ₁ x b ₁ . Since the wedges are connected in the middle of the wide wall of the waveguides, there is no leakage of electromagnetic energy. All wedges have the same angle Φ

, in this example, Φ 5 ^about . There are different sizes of wedges depending on the type of multi-link dividers on their lateral faces and on their position relative to the perimeter of the aperture. In this example, 12 sizes. In FIG. 7, position 62 indicates one of the sizes of the wedge.

 In order to most densely fill the aperture of the PAR with emitters, two or more types of multi-link power dividers are used, in this example, dividers 1:16 and 1: 8. In FIG. 7 shows the location of the outputs of the dividers 1:16 (64) and the dividers 1: 8 (65). In the body of the section of multi-link power dividers, there are openings 66 for passing control communications and power supply of the PAR elements. In the Central hole 67 is a coaxial waveguide axisymmetric multi-channel divider.

 In FIG. 8 shows one of the wedges 62, on one side of which grooves for the multi-link divider 1: 8 (68) are made, and on the other side of the grooves for the multi-link divider 1:16 (69).

In the example of FIG. 8 Φ 5 ^about

 Multi-link dividers 68 consist of double tees 70-75 connected by a Christmas tree pattern. The grooves for the multi-link divider on one side (68) of the wedge are offset with respect to the grooves on the other side (69) of the wedge (see Fig. 8).

In FIG. Figure 9 shows the output double tees (71), (72) formed by grooves on the lateral faces of adjacent radial wedges. Rectangular outlet a ₁ x b ₁ (76) holes are located on the outer end plane 77 of the multi-link divider section.

 In FIG. 10 shows sections of double tees 71, 72 with planes parallel to the end plane 77. The secant planes AI, KK, LL, MM are shown in FIG. 9.

 In double tees 70-75, microwave energy is split in the E-arms. Absorbing loads 78, for example, of ferroepoxide, are installed in the N-arms to improve isolation between the output channels of multi-link dividers. The offset of the double tees 71 and 72 on opposite side faces of the radial wedge relative to each other both in the radial and in the circular directions (see Figs. 9 and 10) allows you to place the H-arms of double tees with absorbing loads in the body of the radial wedges. In this example, the H-arms are in the form of through holes of a rectangular section.

The waveguide parallel power supply system of the HEADLIGHT operates as follows:
Microwave energy through the input divider 15, having a standard waveguide input of rectangular cross section a x b, is supplied to the 4 inputs of the axisymmetric multi-channel divider 16. In the multi-channel axisymmetric divider, the following operations are performed sequentially:
the conversion of waves of type H ₁₀ in four rectangular waveguides into a wave of type H ₀₁ in a coaxial waveguide;
filtering of waves of nonaxisymmetric types in a coaxial having longitudinal currents;
transformation of a wave of type H ₀₁ in a coaxial waveguide into waves of type H ₁₀ in 72 rectangular waveguides, with 24 waveguides having a cross section a ₁ x b ₁ <(a ₁ ≅ a; b ₁ ≅ b), and 48 waveguides have a cross section a ₁ x in _1/2 .

changing the cross section of the waveguides a ₁ x in _1/2 to the cross section a ₁ x b ₁ , so that at the output of the multichannel axisymmetric divider all 72 outputs have one cross section a ₁ x b ₁ , but the microwave energy is doubled to each of the 24 outputs larger than each of the 48 exits.

From the outputs of an axisymmetric multichannel divider, through a section of connecting waveguides of twists 17, microwave energy is supplied to the inputs of multi-link power dividers combined in section 18. From 24 outputs, microwave energy is supplied to 1:16 dividers, and from 48 outputs to dividers 1: 8. The section of multi-link dividers has 768 rectangular outputs a ₁ x b ₁ , which receive the same levels of microwave energy, which ensures close to uniform amplitude distribution in the aperture of the PAR.

 The decoupling between the output waveguide channels is ensured by the use of double tees as part of multi-link dividers and a large number of n divisions in an axisymmetric multi-channel divider.

 Most radars with high energy potential use spatial excitation headlamps, walk-through or reflective. Headlamps with waveguide series or series-parallel power systems have worse characteristics such as broadband and radiated power. The use of the proposed waveguide parallel power system can improve the characteristics of the headlamp and reduce the cost of its manufacture.

 In the case of application of the proposed waveguide parallel power supply system for PAR, the spatial losses characteristic of spatial excitation are eliminated due to radiation falling down to the edges of the aperture and radiation beyond the edges of the aperture. There are no inherent inherent PAR phasor losses due to reflection from the collector aperture, and in the case of reflective phased arrester losses on the "sphericity" of the phase front of the feed. Active losses in the proposed waveguide parallel power supply system for a phased array of ≈1000 elements do not exceed 0.2.0.5 dB due to the short path of microwave energy to each phased array element. Therefore, with the same number of PAR elements, replacing the spatial excitation with the waveguide will increase the gain by 2.3 dB. While maintaining the magnitude of the gain, it is possible to reduce the number of PAR elements by 1.7.2 times, which will lead to a decrease in cost and labor intensity by at least 1.5 times.

 The decrease in the number of PAR elements is carried out while maintaining the dimensions of the aperture and with an unequal arrangement of the elements. In combination with a uniform distribution of microwave energy over the opening, this provides a narrowing of the radiation pattern by ≈ 20% and, therefore, the same increase in accuracy and wide-angle scanning without the appearance of secondary diffraction maxima.

 The waveguide parallel power supply system of the HEADLIGHTS allows you to create a design with the best conditions for heat removal by forced air cooling. The heat-generating elements of the PAR (phase shifters) are directly adjacent to the metal section, which effectively removes heat. The surface of the entire structure of the waveguide parallel power system is more than 2 times the open area of the PAR. The average input microwave power can be increased by a factor of 2.3 compared with spatial excitation.

 The longitudinal size of the waveguide parallel power system is ≈ 1/2 of the diameter of the aperture of the PAR.

 The manufacture of a PARA waveguide parallel power supply system involves the use of high-precision machining centers with programmed control without the need for skilled manual labor. There are no operations of welding, soldering, gluing. There are no galvanic coatings and the use of precious metals is not provided. There are no mass component parts (microwave connectors, cables, etc.).

Claims (5)

1. A waveguide power supply system for a phased antenna array containing an axisymmetric multi-channel power divider, characterized in that an input power divider and a section of multi-link power dividers are introduced into it, while the input power divider is connected to the input of an axisymmetric multi-channel power divider and is made according to the Christmas tree division scheme waveguide tees, between which and at the output waveguide twists are installed, pairwise deployed in opposite directions, axisymmetric multi-channel delhi spruce power is designed as a transition from a rectangular waveguide with the wave H _{1 0} to the coaxial waveguide with the wave H _{0 1} by refillable smooth expansion section of rectangular waveguides by separation of metallic partitions and the transition from the coaxial waveguide with the wave H _{0 1} to n-output rectangular waveguides by installing a coaxial waveguide with the wave _{0 1} H radial metallic partitions and dividers in a section of multi-link power, the number of which is equal to n, each power divider is configured multiaxial On the Christmas tree connection scheme of rectangular waveguides, the input rectangular waveguides of all multi-link power dividers are located around the circumference and are connected respectively to the n output rectangular waveguides of an axisymmetric multi-channel power divider, with an axisymmetric multi-channel power divider located inside the section of multi-link power dividers, and an input power divider inside an axisymmetric multi-channel power divider.  2. The system according to claim 1, characterized in that the section of multi-link power dividers is assembled from wedges diverging radially from the circle on which the input rectangular waveguides of multi-link power dividers are located, on the side faces of which grooves are made that form rectangular waveguides having wedges connected having connector in the middle of wide walls. 3. The system according to claim 1, characterized in that in the axisymmetric multi-channel power divider, the output rectangular waveguides have different cross-sectional sizes, for example, the first n ₁ output rectangular waveguides have a constant cross-section with dimensions a ₁ • b ₁ , the second n ₂ output rectangular waveguides have a variable length cross section with a smooth resizing from a ₁ • b ₁ to a ₁ • b _1/2 , the third n ₃ output rectangular waveguides have a variable longitudinal section with a smooth resizing from a ₁ • b ₁ to a ₁ • b _1/4, etc. the first n ₁ multi-link power dividers connected to the first n ₁ output rectangular waveguides have a division factor of 2k, the second n ₂ multi-link power dividers connected to the second n ₂ output rectangular waveguides have a division coefficient of 2 ^{k - 1} , and the third n ₃ multi-link power dividers connected to n ₃ output rectangular waveguides have a division coefficient of 2 ^{k - 2} , etc. where k 2, 3, 4.  4. The system according to claims 1 and 2, characterized in that the grooves on the opposite side faces of the wedges are made with an offset of half a step.  5. The system according to claims 1, 2 and 4, characterized in that in multi-link power dividers, the individual links of the Christmas tree connection scheme are made in the form of double waveguide tees, the E-arms of which are the arms of power division, and the absorbing loads are installed in the H-arms and H-shoulders are made in the body of the wedges, for example, in the form of through holes.

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