Needle-shaped beam millimeter wave waveguide microstrip hybrid feed antenna array with self-checking function

Abstract

The invention provides a needle-shaped wave beam millimeter wave waveguide micro-strip mixed feed antenna array with a self-checking function. The problems that the gain, the wave beam, the size and the quality of an existing antenna array cannot meet the requirements at the same time, and self-checking cannot be conducted are mainly solved. The antenna comprises a microstrip radiation array plane (1), a waveguide feed network (2) and a microstrip-waveguide converter (3). The micro-strip radiation array plane comprises a plurality of radiation array elements, a micro-strip feeder network, a dielectric plate and a grounding plate; each radiation array element radiates electromagnetic waves through a slotted single-layer patch and forms a two-dimensional micro-strip sub-array with the micro-strip feeder network; and the rear end of the waveguide feed network is connected with a sum-difference network (4) and a waveguide conversion section (5), the sum-difference network (4) comprises three folding waveguide magic T, a three-port power distribution / synthesis waveguide and a detection waveguide, the waveguide conversion section is connected with the waveguide sum-difference network and the standard waveguide, and the detection waveguide performs self-inspection on rear-end equipment of the antenna array. The antenna has the advantages of high gain, narrow beam, miniaturization and light weight, can perform self-inspection on antenna array rear-end equipment, and can be used for airborne and portable radar platforms.

Description

Technical Field

[0001] The invention belongs to the field of millimeter wave radar antennas, and in particular relates to a hybrid feed antenna array, which can be used on airborne and portable radar platforms. Background Art

[0002] With the miniaturization and lightweight design of millimeter-wave radar equipment, the size requirements of the supporting antenna are getting smaller and smaller, and the weight requirements are getting lighter and lighter. The spatial attenuation of the atmosphere in the millimeter-wave frequency band is large, so under the same working distance conditions, the antenna gain requirements are higher and the beam is narrower. Antenna gain is related to the size and form of the antenna. When the antenna gain is determined, the planar size of the antenna is basically determined. After the planar size of the antenna is determined, the miniaturization and lightweight design are closely related to the antenna form.

[0003] Antennas are available in the form of reflector antennas, microstrip antennas, waveguide slot antennas, etc. In the millimeter wave frequency band, reflector antennas are widely used, but they are relatively thick and large in size; microstrip antennas have large feeder losses and low efficiency, and are not easy to meet gain index requirements under the premise of requiring low side lobes; waveguide slot antennas are heavy and cannot meet weight index requirements.

[0004] When using radar equipment, it is necessary to regularly inspect the equipment to detect the equipment itself, especially the equipment at the back end of the antenna. The commonly used method is to use external calibration equipment, which is very inconvenient due to the influence of the site and environment.

[0005] The patent document with application number 202122300682.6 discloses a fan-beam microstrip antenna array, which connects several microstrip patches arranged according to the feed network through a microstrip feed line and connects to a waveguide power divider to achieve power distribution, forming a long strip fan-beam antenna array with relatively high gain and relatively simple structure. Although the antenna array has a higher gain than traditional antennas, it cannot meet the high gain and needle beam requirements of millimeter-wave radars because its beam is fan-shaped; at the same time, it is not convenient for radars to be regularly inspected because there is no self-test port; in addition, since the antenna microstrip is implemented by multi-layer microstrip electromagnetic coupling, the processing technology is relatively complex. Summary of the invention

[0006] The purpose of the present invention is to address the deficiencies of the above-mentioned prior art and propose a needle-beam millimeter-wave waveguide-microstrip hybrid fed antenna array with a self-checking function to meet the high gain and narrow beam requirements of millimeter-wave band radars; meet the requirements of radar miniaturization and lightweight design, and facilitate self-checking of the antenna array back-end equipment.

[0007] The technical idea to achieve the purpose of the present invention is to: x ×N yThe system is divided into specific 4×N microstrip sub-arrays, and the microstrip feeder network is used to connect the radiating array elements inside the microstrip sub-array to meet the high gain and narrow beam requirements of millimeter wave radar, where N = 2, 3, ..., N x 、N y is an even number greater than 2; the microstrip sub-array is connected to the low-profile non-standard waveguide feeding network through a microstrip-waveguide converter, and the low-profile non-standard waveguide interface is connected to the standard waveguide interface through a waveguide transformation section to meet the requirements of radar miniaturization and lightweight design; a self-test waveguide is added to the low-profile non-standard waveguide and difference network to meet the self-test of the antenna array back-end equipment.

[0008] According to the above technical ideas, the needle-beam millimeter-wave waveguide-microstrip hybrid feeding antenna array with self-checking function of the present invention includes a microstrip radiation array, a waveguide feeding network, and a microstrip-waveguide converter, and is characterized by:

[0009] The microstrip radiation array includes a plurality of microstrip sub-arrays, each of which is composed of a plurality of radiation array elements, a microstrip feeder network, a dielectric plate and a ground plate. Each radiation array element radiates electromagnetic waves through a single-layer patch slot and is connected to the microstrip feeder network to form a microstrip sub-array;

[0010] The waveguide feeding network adopts a low-profile waveguide structure whose waveguide height is 0.4 to 0.6 times the standard waveguide height, and its rear end is connected with a waveguide sum difference network and a waveguide conversion section, and the waveguide conversion section is used to connect the waveguide sum difference network and the standard waveguide;

[0011] The waveguide sum-difference network adopts a low-profile waveguide structure whose waveguide height is 0.4 to 0.6 times the standard waveguide height, and comprises three folded waveguide magic Ts, a three-port power distribution / synthesis waveguide and a detection waveguide;

[0012] The folded waveguide magic T and three-port power distribution / synthesizing waveguide are used to synthesize the signal output by the waveguide feeding network and the azimuth difference and elevation difference signals to achieve target positioning and tracking;

[0013] The detection waveguide is used for self-test of the back-end equipment of the antenna array.

[0014] Furthermore, each radiating array element radiates electromagnetic waves by means of rectangular patch slots, and impedance matching with the microstrip feeder network is achieved by adjusting the depth and width of the patch slots; the radiating array elements of the single-layer structure and the microstrip feeder network are both distributed on the upper surface of the dielectric plate, and the number of rows of the radiating array elements N is x and the number of columns N y are all even numbers greater than 2; the grounding plate is distributed on the lower surface of the dielectric plate.

[0015] Furthermore, the detection waveguide performs self-inspection on the antenna array back-end device by connecting the detection waveguide port to the port of the antenna array back-end device, so that the internal excitation source of the antenna array back-end device transmits a calibration signal, and records the output signal coupled back by the detection waveguide port to the back-end device display, and determines whether the back-end device is qualified by comparing the recorded result with the calibration signal, thereby completing the self-inspection.

[0016] Furthermore, the foldable waveguide magic contains adjustable metal media and adjustable parameters inside, and the adjustable parameters include: metal medium base radius r1, metal medium upper port radius r2, metal medium height h1, metal medium position s1; the three-port power distribution and synthesis waveguide contains two curved waveguides with a radius of r3 and waveguide arms of L1; the detection waveguide is composed of a curved waveguide with a radius of r4 and a rectangular waveguide with a length of L2, a width of w1, and a position of s2.

[0017] Furthermore, the waveguide transformation section is composed of three sections of rectangular waveguides, and the waveguide transformation function is achieved by adjusting the length L3 and the height H of the second waveguide.

[0018] Furthermore, the microstrip feeding network is composed of a plurality of microstrip lines of different widths, and the impedance and width of each microstrip line are determined by calculating the impedance matching formula according to the power distribution requirements and the output impedance of the radiation array element.

[0019] Furthermore, the waveguide feeding network includes a plurality of waveguide power dividers, each waveguide power divider is composed of three rectangular waveguides, and the power-to-centimeter ratio of the waveguide power divider is determined based on power calculation of the microstrip subarray.

[0020] Furthermore, the microstrip-waveguide converter is composed of a metal inner core, a metal sheet, a waveguide and an insulating medium. One end of the metal inner core is inserted into the waveguide, and the other end is connected to the feeding point of the microstrip subarray. The metal sheet is located in the cavity of the waveguide.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] Firstly, the microstrip radiation array of the present invention adopts a plurality of microstrip sub-arrays, and a microstrip feeder network is connected after the radiation array element, thereby improving the gain of the antenna beam and reducing the beam width;

[0023] Secondly, since the present invention connects a waveguide sum and difference network at the rear end of the waveguide feeding network, it can not only synthesize the signal output by the waveguide feeding network into a sum signal and an azimuth difference and an elevation difference signal to realize the positioning and tracking of the target, but also realize the self-inspection of the rear-end equipment of the antenna array, and since the position of the detection port is relatively fixed, the self-inspection data is more stable and accurate;

[0024] Thirdly, since the waveguide feeding network, the waveguide and the difference network all adopt low-profile structures, the size and weight of the antenna array are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a needle-beam millimeter-wave waveguide-microstrip hybrid feed antenna array with a self-checking function according to the present invention;

[0026] Figure 2 Schematic diagram of the distribution of the microstrip radiation array in the present invention;

[0027] Figure 3 Schematic diagram of the microstrip subarray in the present invention;

[0028] Figure 4 A schematic diagram of a microstrip-waveguide converter in the present invention;

[0029] Figure 5 It is a schematic diagram of the waveguide feeding network, waveguide sum and difference network and waveguide transformation section in the present invention;

[0030] Figure 6 Schematic diagram of the waveguide sum-difference network in the present invention;

[0031] Figure 7 A schematic diagram of a three-port power distribution / synthesis waveguide in the present invention;

[0032] Figure 8 Schematic diagram of the detection waveguide in the present invention;

[0033] Fig. 9 It is a schematic diagram of the foldable waveguide magic T in the present invention;

[0034] Fig.10 It is a schematic diagram of the waveguide transformation section in the present invention;

[0035] Fig.11 It is a simulation result diagram of the radiation characteristics of the sum port azimuth plane of the present invention;

[0036] Fig.12 It is the simulation result of the radiation characteristics of the port pitch surface of the present invention;

[0037] Fig.13 It is the simulation result of the azimuth difference radiation characteristic of the present invention;

[0038] Fig.14 This is the simulation result of the elevation difference radiation characteristic of the present invention. DETAILED DESCRIPTION

[0039] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] Reference Figure 1 ,in Figure 1a is a top view of the overall structure of the present invention, Figure 1 b is the main view of the overall structure of the present invention. The needle-beam millimeter-wave waveguide-microstrip hybrid feeding antenna array with self-checking function in this example includes: microstrip radiation array 1, waveguide feeding network 2, microstrip-waveguide converter 3, waveguide sum-difference network 4 and waveguide transformation section 5; this example can be divided into three layers from top to bottom, wherein the microstrip radiation array 1 is located at the top layer, the waveguide feeding network 2 is located at the middle layer, the microstrip-waveguide converter 3 is located between the microstrip radiation array 1 and the waveguide feeding network 2, the waveguide sum-difference network 4 is located at the rear end of the waveguide feeding network 2, and the waveguide transformation section 5 is located at the rear end of the waveguide sum-difference network 4, i.e., the bottom layer.

[0041] When the antenna array is in the transmitting state, only the sum port of the waveguide sum difference network 4 works, and the energy enters the sum port of the waveguide sum difference network 4 from the waveguide transformation section 5. At this time, the waveguide sum difference network 4 distributes the energy for the first time, and evenly distributes the energy to each input port of the waveguide feeding network 2. The energy undergoes a second power distribution in the waveguide feeding network 2, and the energy after power distribution is transferred to the microstrip radiation array 1 through the microstrip-waveguide converter 3. In the microstrip radiation array 1, when the energy is distributed to each radiation array element for the third time by the feeder network, electromagnetic waves will be radiated. These electromagnetic waves are vector synthesized to form a needle beam to emit electromagnetic waves.

[0042] When the antenna array is in the receiving state, the sum port, azimuth difference port, and elevation difference port of the waveguide sum-difference network 4 are all in working state; the microstrip radiation array 1 receives electromagnetic waves, synthesizes the power through the microstrip feeder network, and transmits it to the waveguide feeding network 2 through the microstrip-waveguide converter 3 for secondary power synthesis. The signal after power synthesis enters the waveguide sum-difference network 4, converts the energy signal into a sum signal and an azimuth difference and elevation difference signal output. The output signal enters the waveguide conversion section 5 and is input into the antenna array back-end device.

[0043] Reference Figure 2 The microstrip radiation array 1 includes 4×N microstrip sub-arrays, the number of which is related to the sidelobe level SLL and the sum and difference beams of the antenna array. The power distribution of the microstrip radiation array 1 can be determined by the sidelobe level SLL. According to the power distribution of the microstrip radiation array 1 and the radiation array distribution characteristics of the sum and difference beams, the entire microstrip radiation array 1 is divided into 4 areas with the same power, and each area is divided into N small areas (N=2, 3...), and the power values ​​of the N small areas are distributed in a symmetrical structure around the center of the array.

[0044] In this example, the operating frequency band is set to but not limited to 33 GHz, the sum gain is set to but not limited to 40 dB, the lobe width is set to but not limited to ≤1.4°, the side lobe level is set to but not limited to ≤-23 dB, and the dielectric plate material is set to but not limited to ε r=2.2, h = 0.508mm, tanδ = 0.0008 SJ9220 microwave laminate. According to the set parameters, the array azimuth spacing d of the microstrip radiation array element can be calculated and determined. x =6.68mm, quantity N x =66; pitch distance d y =6.68mm, quantity N y =64, where d x d y They represent the radiating element spacing in the x direction and the y direction when the antenna array is distributed in the xoy plane in the rectangular coordinate system, N x 、N y They respectively represent the number of radiating elements in the x-direction and y-direction of the antenna array in the rectangular coordinate system, and the antenna aperture size is 450mm×440mm.

[0045] Each of the above-mentioned microstrip subarrays includes: a radiating element 11, a microstrip feeder network 12, a dielectric plate 13 and a ground plate 14, wherein the radiating element 11 and the microstrip feeder network 12 are distributed on the upper layer of the dielectric plate 13, and the ground plate 14 is distributed on the lower layer of the dielectric plate 13, such as Figure 3 As shown, 3(a) is a top view of the microstrip subarray structure, and 3(b) is a side view of the microstrip subarray structure.

[0046] The radiating element 11 is a microstrip line edge-fed rectangular patch, and impedance matching with the microstrip feeder network is achieved by adjusting the patch slot depth cw and width cl. Considering the edge effect, the width W and length L parameters of the rectangular microstrip antenna patch are determined as follows:

[0047]

[0048] in, is the stretching length caused by the edge effect;

[0049] is the equivalent relative dielectric constant of the dielectric plate;

[0050] c is the speed of light in free space, ε r is the relative dielectric constant of the dielectric substrate, f is the working center frequency of the microstrip antenna, and h is the thickness of the dielectric substrate;

[0051] According to the above-mentioned microstrip sub-array arrangement and dielectric plate material, the size of the radiating element 11 is obtained from the rectangular microstrip antenna patch calculation formula: W = 3.7mm, L = 2.7mm; through simulation optimization, the optimal dimensions of the slot depth cw and width cl of the radiating element 11 are obtained as follows: cw = 3.7mm, cl = 1.0mm.

[0052] The microstrip feeder network 12 is composed of a plurality of microstrip lines of different widths. The impedance and width of each microstrip line are determined by impedance matching formula according to the power distribution requirements and the impedance of the output end of the radiating element. In this example, the power distribution of each radiating element is but not limited to Taylor distribution. Let PM(i) represent the power energy of the i-th radiating element i=1, 2, 3... The impedance corresponding to each row of the line array is the same, that is, only one column of feeders connected to the feeding point and any row of microstrip feeders need to be selected, and their widths can be calculated by impedance matching to obtain the widths of all microstrip lines in the microstrip feeding network.

[0053] Assume that the output impedance Z0 of each radiating element is 140Ω, and the first radiating element is fed by a microstrip line with impedance Z0. The width of the microstrip line connecting other radiating elements in the feeding network needs to be calculated by impedance matching transformation. Take the feeder connecting the third radiating element as an example: the energy flows from the center of the array to the edge unit. When the energy is transferred to the third unit, it will be divided into two paths, one flowing into the third unit, and the other flowing to the first and second units along the feeding network. Assume that the energy is microstrip line A1 before diversion and microstrip line B1 when flowing into the first and second units. According to the transmission line theory and impedance matching formula, the width W″ parameter of microstrip line A1 is determined as follows:

[0054]

[0055] in,

[0056]

[0057] In this example, the width W″ of the microstrip line A1 is calculated to be 0.656 mm. Similarly, the widths of all microstrip lines of the entire microstrip feeding network 12 can be determined.

[0058] Reference Figure 4 The microstrip-waveguide converter 3 is composed of a coaxial core 31, a metal sheet 32, a waveguide 33 and an insulating medium 34. One end of the coaxial core 31 is inserted into the waveguide 33, and the other end is connected to the feeding port of the microstrip subarray. The metal sheet 32 ​​is located in the cavity of the waveguide 33. The part of the coaxial core 31 exposed to the air is wrapped by the insulating medium 34. One end of the waveguide 33 is a short-circuit port, and the other end is connected to the waveguide feeding network 2. The performance of the microstrip-waveguide converter 3 can be optimized by changing the position of the coaxial core 31, the length of the inserted waveguide 33 and the size of the metal sheet 32.

[0059] In this example, the impedance at the upper end of the microstrip-waveguide converter is but not limited to 50Ω; the coaxial core 31 is made of but not limited to copper, the insulating medium 34 is made of but not limited to polytetrafluoroethylene, and the ratio of the diameter of the device to the coaxial core 31 is 3.3:1; the distance between the metal core and the short-circuit end of the waveguide is 1.8mm; the inner wall dimensions of the waveguide end are respectively but not limited to 7.112mm and 1.778mm; the metal sheet is made of but not limited to a rectangular aluminum sheet, the size is but not limited to 1mm×2mm×0.5mm, and the distance from the short-circuit end of the waveguide is but not limited to 4.87mm.

[0060] Reference Figure 5 The rear end of the waveguide feeding network 2 is connected to the waveguide sum difference network 4, and the two are located in the same layer. Each output port of the waveguide sum difference network 4 is connected to a waveguide transformation section 5. The waveguide feeding network 2 includes a plurality of waveguide power dividers, each of which is composed of three rectangular waveguides, and the height of each rectangular waveguide is 0.4 to 0.6 times the height of the standard waveguide. The centimeter ratio of each waveguide power divider is determined according to the power calculation of the corresponding microstrip subarray.

[0061] In this example, the standard waveguide size table is queried according to the antenna array operating frequency, and the standard waveguide of model BJ320 is selected, which has a size of 7.12mm×3.556mm, so the rectangular waveguide size is but not limited to 7.12mm×1.778mm, the power division ratio of the required waveguide power divider is but not limited to 1.45 and 1.22, and the total number of waveguide power dividers is but not limited to 12, including 8 waveguide power dividers with a power division ratio of 1.45 and 4 waveguides with a power division ratio of 1.22. The waveguide sum network 4 uses a low-profile waveguide with a height of 0.4 to 0.6 times the height of the standard waveguide.

[0062] Reference Figure 6 The waveguide sum-difference network 4 uses a low-profile waveguide with a height of 0.4 to 0.6 times the height of a standard waveguide, and includes a first folded waveguide magic T41, a second folded waveguide magic T42, a third folded waveguide magic T43, a three-port power distribution / synthesis waveguide 44, and a detection waveguide 45. The waveguide sum-difference network 4 has a total of 8 ports, of which 4 input ports are connected to the waveguide feeding network 2, and the 4 output ports are respectively a sum port, an azimuth difference port, a pitch difference port, and a detection port.

[0063] The first folded waveguide magic T41, the second folded waveguide magic T42 and the third folded waveguide magic T43 are all composed of four rectangular waveguides and a metal medium, wherein the metal medium is composed of a metal frustum and a metal rod, and the metal medium is located inside the structure composed of the four rectangular waveguides. The adjustment parameters of the metal medium include: the radius r1 of the metal medium base, the radius r2 of the upper port of the metal medium, the height h1 of the metal medium, and the position s1 of the metal medium. Figure 7 As shown;

[0064] The three-port power distribution / synthesis waveguide 44 is composed of three rectangular waveguides, a curved waveguide 441 and a curved waveguide 442, wherein the radius of the curved waveguides is r3 and the length of the waveguide arms is L1. Figure 8 As shown;

[0065] The detection waveguide 45 is composed of a curved waveguide 451 with a radius of r4 and a rectangular waveguide 452 with a length of L2, a width of w1, and a position of s2. Fig. 9 The detection waveguide 45 is located on the waveguide arm of the first folded waveguide magic T41, and the two are connected by a rectangular waveguide 452, one end of which is close to the and port is the detection port, and the other end is connected to the matching load, and the coupling form is not limited.

[0066] Through the combined structure formed by the folded waveguide magic T41, the folded waveguide magic T42, the folded waveguide magic T43 and the three-port power distribution / synthesizing waveguide 44, the signal output by the waveguide feeding network 2 can be synthesized into a sum signal and an azimuth difference and an elevation difference signal, thereby realizing the positioning and tracking of the target;

[0067] The detection waveguide 45 can replace the external calibration equipment to realize the self-test function, and because the relative position of the detection port and the sum, azimuth difference, and pitch difference ports is fixed, the self-test data is more accurate. The operation method is: connect the detection waveguide port to the port of the antenna array back-end device, so that the internal excitation source of the antenna array back-end device emits a calibration signal, record the output signal coupled back to the back-end device display by the detection waveguide port, and judge whether the back-end device is qualified by comparing the recorded result with the calibration signal to complete the self-test.

[0068] In this example, the detection waveguide transmits energy by single-port coupling, and the port size of all waveguides in the waveguide and difference network 4 is but not limited to 7.12mm×1.778mm. The following parameter values ​​are obtained through simulation optimization: r1=3mm, r2=0.5mm, h1=3.7mm, s1=3.356mm, r3=16mm, L1=52.8mm, r4=9.112mm, L2=3.3mm, w1=1.5mm, s2=16.8mm.

[0069] refer to Fig.10 The waveguide transformation section 5 is composed of a first waveguide 51, a second waveguide 52 and a third waveguide 53. The waveguide transformation function is achieved by adjusting the length L3 and the height H of the second waveguide 52.

[0070] In this example, the waveguide 51 is a standard waveguide, and its dimensions are but not limited to the dimensions of the standard waveguide BJ320, i.e., 7.112 mm×3.556 mm; the second waveguide 52 has dimensions of but not limited to 7.112 mm×2.77 mm×2.52 mm, a length L3 of but not limited to 2.77 mm, and a height H of but not limited to 2.52 mm; the dimensions of the third waveguide 53 are but not limited to 7.12 mm×1.778 mm.

[0071] The effect of the present invention can be further illustrated by the following simulation results.

[0072] 1. Simulation conditions

[0073] An antenna array model is established in the MATLAB electromagnetic simulation analysis software.

[0074] 2. Simulation content

[0075] Simulation 1, under the above conditions, the radiation characteristics of the azimuth surface of the port of the present invention are simulated, and the results are as follows Fig.11 As shown, from Fig.11 It can be seen that the azimuth and gain are 40.2dB, the lobe width is 1.2767°, and the sidelobe level is -26.02dB;

[0076] Simulation 2: Under the above conditions, the radiation characteristics of the port elevation surface of the present invention are simulated, and the results are as follows: Fig.12 As shown, from Fig.12 It can be seen that the pitch and gain are 40.2dB, the lobe width is 1.2983°, and the sidelobe level is -25.17dB;

[0077] Simulation 3, under the above conditions, the azimuth difference radiation characteristics of the present invention are simulated, and the results are as follows Fig.13 shown; from Fig.13 It can be seen that the azimuth difference gain is 36.3dB and the azimuth zero depth is -38.05dB;

[0078] Simulation 4: Under the above conditions, the elevation difference radiation characteristics of the present invention are simulated, and the results are as follows: Fig.14 shown; from Fig.14 It can be seen that the pitch difference gain is 36.7dB and the zero value depth is -43.12dB.

[0079] The above simulation results show that the antenna array of the present invention has high-gain, narrow-lobe needle-beam single-pulse radiation performance.

[0080] The above description is only a specific example of the present invention and does not constitute any limitation to the present invention. It is obvious that for professionals in this field, after understanding the content and principles of the present invention, it is possible to make various modifications and changes in form and details without departing from the principles and structures of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A needle-beam millimeter-wave waveguide-microstrip hybrid feeding antenna array with a self-checking function, comprising a microstrip radiation array (1), a waveguide feeding network (2), and a microstrip-waveguide converter (3), characterized in that: The microstrip radiation array (1) comprises a plurality of microstrip sub-arrays, each of which is composed of a plurality of radiation array elements (11), a microstrip feeder network (12), a dielectric plate (13), and a ground plate (14); each radiation array element radiates electromagnetic waves through a single-layer patch slot and is connected to the microstrip feeder network to form a microstrip sub-array; The waveguide feeding network (2) adopts a low-profile waveguide structure in which the waveguide height is 0.4 to 0.6 times the standard waveguide height, and the rear end is connected with a waveguide sum difference network (4) and a waveguide conversion section (5), and the waveguide conversion section (5) is used to connect the waveguide sum difference network and the standard waveguide; The waveguide sum-difference network (4) adopts a low-profile waveguide structure whose waveguide height is 0.4 to 0.6 times the standard waveguide height, and comprises three folded waveguide magic Ts (41, 42, 43), a three-port power distribution / synthesis waveguide (44) and a detection waveguide (45); The folded waveguide magic T (41, 42, 43) and the three-port power distribution / synthesis waveguide (44) are used to synthesize the signal output by the waveguide feeding network (2) into a sum signal and an azimuth difference and an elevation difference signal, so as to realize the positioning and tracking of the target; The detection waveguide (45) is used for self-detection of the rear-end equipment of the antenna array.

2. The antenna array according to claim 1, characterized in that: Each radiating array element radiates electromagnetic waves by means of rectangular patch slots, and impedance matching with the microstrip feeder network is achieved by adjusting the depth and width of the patch slots; The radiation array elements (11) of the single-layer structure and the microstrip feeder network (12) are both distributed on the upper surface of the dielectric plate (13), and the number of rows of the radiation array elements is N. x , and the number of columns N y All are even numbers greater than 2; The grounding plate (14) is distributed on the lower surface of the dielectric plate (13).

3. The antenna array according to claim 1, characterized in that: The detection waveguide (45) performs self-inspection on the antenna array back-end device by connecting the detection waveguide port to the antenna array back-end device port, causing the internal excitation source of the antenna array back-end device to emit a calibration signal, recording the output signal coupled back to the back-end device display by the detection waveguide port, and comparing the recorded result with the calibration signal to determine whether the back-end device is qualified, thereby completing the self-inspection.

4. The antenna array according to claim 1, characterized in that: The foldable waveguide magic T (41, 42, 43) contains adjustable metal medium and adjustable parameters, wherein the adjustable parameters include: the radius r1 of the metal medium base, the radius r2 of the metal medium upper port, the height h1 of the metal medium, and the position s1 of the metal medium; The three-port power distribution / synthesis waveguide (44) comprises two curved waveguides (441, 442) each having a radius of r3 and waveguide arms of L1; The detection waveguide (45) is composed of a curved waveguide (451) with a radius of r4 and a rectangular waveguide (452) with a length of L2, a width of w1, and a position of s2; By adjusting the parameters of the metal medium and the curved waveguide (441, 442), the electrical performance of the waveguide sum and difference network is optimized, so that the sum signal and the azimuth difference and elevation difference signals have higher accuracy and lower power loss, thereby achieving target positioning and tracking; By adjusting the adjustable parameters of the rectangular waveguide (452), the detection waveguide performance is optimized, so that the energy passing through the detection port is more stably coupled to the sum port, the azimuth difference port and the elevation difference port, thereby realizing the self-inspection of the back-end equipment.

5. The antenna array according to claim 1, characterized in that: The waveguide transformation section (5) is composed of three waveguides (51, 52, 53) of different sizes, and the waveguide transformation function is achieved by adjusting the length L3 and the height H of the second waveguide (52).

6. The antenna array according to claim 1, characterized in that: The microstrip feeding network (12) is composed of a plurality of microstrip lines of different widths, and the impedance and width of each microstrip line are determined by calculating the impedance matching formula according to the power distribution requirements and the output impedance of the radiation array element.

7. The antenna array according to claim 1, characterized in that: The waveguide feeding network (2) comprises a plurality of waveguide power dividers, each waveguide power divider is composed of three rectangular waveguides, and the power division ratio of the waveguide power divider is determined by power calculation of the microstrip subarray.

8. The antenna array according to claim 1, characterized in that: The microstrip-waveguide converter (3) is composed of a metal inner core (31), a metal sheet (32), a waveguide (33) and an insulating medium (34); one end of the metal inner core (31) is inserted into the waveguide (33), and the other end is connected to a feeding point of a microstrip subarray; the metal sheet (32) is located in the cavity of the waveguide (33).

9. The antenna array according to claim 1, characterized in that: The number of microstrip-waveguide converters and the number of waveguide feeding network input ports are the same as the number of microstrip subarrays, that is, both are 4×N, where N is a positive integer greater than 1.

10. The antenna array according to claim 1, characterized in that: The dimensions of the low-profile waveguides used in the waveguide feed network and the waveguide sum and difference network are selected based on the transmission characteristics of the rectangular waveguide.

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