A millimeter wave single pulse filtering array antenna based on gap waveguide and differential network feed

Abstract

The application discloses a millimeter wave single-pulse filtering array antenna based on a gap waveguide and a difference network feed, which comprises an SIW filtering antenna array and a GWG and difference network structure; the GWG and difference network structure is composed of three layers of metal plates with square metal pins, adjacent two layers of metal plates are filled with air, and adjacent two layers of metal plates and the protruding pins form a GWG unit; the SIW filtering antenna array is composed of three layers of dielectric substrates covered with metal layers and a layer of prepreg, metal holes are loaded in the dielectric substrates and the prepreg to form resonant cavities of the antenna, and slots are loaded on the metal layers to realize the coupling between the cavities and the radiation of the antenna. The application combines the filtering antenna with the single-pulse antenna, simultaneously has the frequency selection characteristic of the filtering antenna and the high-precision target positioning characteristic of the single-pulse antenna, and has the advantages of high integration and multi-function.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding. Background Art

[0002] Antennas are essential components for wireless communication systems, converting energy in the form of guided waves into electromagnetic energy in space. With the development of modern wireless communications, antennas are becoming more multifunctional, intelligent, miniaturized, and integrated. This has led to the emergence of various types, including horn antennas, waveguide slot antennas, and microstrip antennas. Furthermore, specialized antenna forms, such as filter antennas and monopulse antennas, have emerged to meet the increasingly diverse needs of today's wireless communication systems.

[0003] A filter antenna is an antenna with a filtering function. It can filter signals within a specific frequency range while receiving or transmitting, thereby improving system reliability. In recent years, the development of wireless communication and modern integrated circuit technology has placed demands on mobile terminal devices for multifunctionality, miniaturization, and integration. However, in traditional RF front-ends, filters and antennas are designed independently, resulting in large physical size and high insertion loss. Therefore, microstrip antennas, which combine radiation and filtering functions with high efficiency, low loss, and miniaturization, have been widely researched and applied.

[0004] The rapid development of rockets, missiles, satellites, and aerospace technology has placed new demands on tracking radars for tracking speed, accuracy, range, and anti-interference capabilities. The tracking accuracy and speed of the previously used conical scanning and sequential beam methods could no longer meet these increasingly stringent requirements, leading to the emergence of monopulse technology. Monopulse technology uses the different beams of a single echo pulse to obtain complete angular error information about a target. Essentially, this technology adds and subtracts the echo signals received from several beams, obtaining target range information in the sum branch and target off-axis information in azimuth and elevation, respectively, using the azimuth and elevation difference branches. This control controls the motor movement in the direction that minimizes the error until the antenna axis is aligned with the target, achieving tracking. Compared to conical scanning radars, radars using monopulse systems can rapidly obtain target angular position information, improving tracking accuracy by one to two orders of magnitude. Furthermore, fluctuations in the echo signal amplitude do not significantly affect the accuracy of angular coordinate measurements. Monopulse radar antennas offer both precise positioning and rapid response capabilities, and are gaining increasing attention as radars track increasingly fast moving targets.

[0005] Wireless communication devices are trending towards portability and multifunctionality. Integrating multiple functions into a single component can reduce both device size and energy loss during transmission. Therefore, combining filtering antenna elements with monopulse feed networks to design monopulse antennas with filtering capabilities is a research direction of practical significance. Summary of the Invention

[0006] The purpose of the present invention is to propose a millimeter-wave single-pulse filter array antenna based on gap waveguide and difference network feeding, which has the advantages of high precision and high integration, and can meet the needs of communication and detection systems for multifunctional and highly integrated antennas.

[0007] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0008] A millimeter-wave monopulse filter array antenna based on gap waveguide sum-difference network feeding, comprising a SIW filter antenna array composed of metal vias and metal layer slots loaded on a microstrip multilayer board structure, and a GWG sum-difference network structure composed of a metal plate with square pins;

[0009] The GWG sum-difference network structure consists of three layers of metal plates with square metal pins. The space between two adjacent metal plates is filled with air. The two adjacent metal plates and the protruding pins form a GWG unit. Electromagnetic waves are transmitted in the waveguide structure surrounded by the pins. After energy is fed into the sum port or difference port, it passes through the two-layer feeding network and is coupled into the SIW filter antenna array through the slots loaded on the surface of the metal plate.

[0010] The SIW filter antenna array consists of three dielectric substrates covered with metal layers and a prepreg. Metal holes are added in the dielectric substrates and the prepreg to form the antenna's resonant cavity, and slots are added on the metal layers to achieve coupling between the cavities and antenna radiation. Energy is coupled into the array through the slots added on the metal layer on the lower surface of the bottom dielectric substrate, transmitted through the resonant cavity, and then radiated into free space through the slots added on the metal layer on the upper surface of the top dielectric substrate.

[0011] Furthermore, the operating frequencies of the SIW filter antenna array and the GWG sum-difference network structure match, and both operate in the millimeter wave frequency band.

[0012] Furthermore, the gaps loaded by the top metal plate correspond one-to-one to the gaps loaded by the metal layer below the bottom dielectric substrate, and the size of the gaps loaded by the top metal plate is larger than the size of the gaps loaded by the metal layer below the bottom dielectric substrate.

[0013] Furthermore, the SIW filter antenna array is formed by stacking a first dielectric substrate, a prepreg, a second dielectric substrate, and a third dielectric substrate, wherein the surfaces of the first dielectric substrate, the second dielectric substrate, and the third dielectric substrate are covered with a metal layer; a first metal via passes through the first dielectric substrate, the prepreg, and the second dielectric substrate, and together with the metal layers on the upper and lower surfaces of the first and second substrates, forms a secondary resonant cavity and a tertiary resonant cavity of the antenna; a second metal via is located in the third dielectric substrate, and together with the metal layers on the upper and lower surfaces of the third dielectric substrate, forms a feeding path and a primary resonant cavity of the antenna;

[0014] Energy is coupled into the cavity through the slots loaded on the metal layer on the lower surface of the third dielectric substrate, and after being transmitted in the feed path and the first-level resonant cavity composed of the third dielectric substrate and the metal layers on its upper and lower surfaces and the metal vias, enters the second-level resonant cavity composed of the second dielectric substrate and its upper and lower surface metal layers and the metal vias through the coupling slots loaded on the metal layer on the upper surface of the third dielectric substrate, and then enters the third-level resonant cavity composed of the first dielectric substrate and the metal vias on its upper and lower surface metal layers through the coupling slots loaded on the metal layer on the upper surface of the second dielectric substrate and the metal layer on the lower surface of the first dielectric substrate, and finally radiates into free space through the slots loaded on the metal layer on the upper surface of the first dielectric substrate.

[0015] Furthermore, the SIW filter antenna array is formed by connecting 32 antenna units in series in a 2×16 layout.

[0016] Furthermore, the metal layer on the upper surface of the first dielectric substrate is an antenna radiation layer, and a plurality of slots are provided above the metal layer. Every two slots constitute a radiation unit of the antenna, and 32 radiation units are arranged in a 2×16 layout to form an antenna array;

[0017] The metal layer on the lower surface of the first dielectric substrate and the metal layer on the upper surface of the second dielectric substrate serve as first coupling slot layers, through which electromagnetic energy enters the third resonant cavity from the secondary resonant cavity; the first coupling slots are arranged in a 2×16 layout;

[0018] The metal layer on the lower surface of the second dielectric substrate is a second coupling slot layer, and electromagnetic energy enters the secondary resonant cavity from the primary resonant cavity through the second coupling slots, and the second coupling slots are arranged in a 2×16 layout;

[0019] The metal layer on the lower surface of the third dielectric substrate is a third coupling slot layer. Electromagnetic energy enters the SIW feeding structure and the first-order resonant cavity at the bottom layer of the SIW filter antenna array from the GWG sum-difference network structure through the third coupling slots. The third coupling slots are arranged in a 2×16 layout; wherein the third coupling slots are arranged obliquely, with the direction being counterclockwise or clockwise rotated at a preset angle based on the x-axis direction, and adjacent slots in the y-axis direction rotate in opposite directions, so that the electromagnetic energy input to the antenna unit is in phase, and adjacent slots in the x-axis direction rotate in the same direction.

[0020] Furthermore, the GWG sum-difference network structure includes a first metal plate, a second metal plate, and a third metal plate stacked together with square metal pins. The square pins on the lower surface of the first metal plate and the square pins on the upper surface of the second metal plate constitute an upper-layer GWG sum-difference network, and the square pins on the lower surface of the second metal plate and the square pins on the upper surface of the third metal plate constitute a lower-layer GWG sum-difference network. The space between the two layers of metal plates is filled with air. The lower-layer GWG sum-difference network has two input ports, sum and difference. After energy is fed into the sum port or the difference port, it passes through two layers of feeding networks and is coupled into the microstrip antenna array through the gap loaded on the upper surface of the first metal plate.

[0021] Furthermore, the GWG sum difference network structure includes a middle-upper layer transmission structure and a middle-lower layer transmission structure;

[0022] The upper-middle transmission structure is divided into two symmetrical upper and lower parts, each consisting of a T-shaped power splitter structure and a folded angle structure; the sum port coupling slot is located at the tail of the folded angle, and the difference port coupling slot is located in the middle of the T-shaped power splitter; after energy is coupled into the upper layer by the lower transmission structure, it passes through the T-shaped power splitter and enters the antenna array through the slots on the metal layer below the first metal plate and the bottom dielectric substrate;

[0023] The middle and lower transmission structure is divided into two parts, left and right, each of which has an input port, with the left side being the sum port and the right side being the difference port; after the energy is input from the sum / difference port, it enters the upper transmission structure of the GWG sum and difference network structure through the coupling gap on the second metal plate.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] First, the present invention presents a millimeter-wave monopulse filter array antenna based on gap waveguide and differential network feeding. This antenna array implements a SIW multi-stage cavity by inserting metal vias into a dielectric substrate with printed metal layers on its upper and lower surfaces. This antenna utilizes coupling between the multi-stage cavities to achieve filtering performance. The addition of metal vias to achieve the multi-stage cavity does not increase the overall structural complexity, resulting in superior filtering performance without increasing manufacturing difficulty. Furthermore, the SIW feed structure facilitates integration with the feed network, facilitating the design of larger-scale antenna arrays.

[0026] Second, the present invention's millimeter-wave monopulse filter array antenna, based on a gap waveguide sum-difference network feed, uses a GWG sum-difference network to generate 0° and 180° phase differences through a waveguide magic-T structure, simplifying the sum-difference beam generation required by the monopulse antenna. Energy is transmitted through the air gaps of the GWG, avoiding transmission losses in the dielectric plate and improving antenna efficiency.

[0027] Third, the millimeter-wave single-pulse filter array antenna based on gap waveguide and difference network feeding of the present invention, the proposed GWG and difference network is coupled with the filter antenna array through slots, and the SIW waveguide structure feeds the antenna units in the form of series feeding, which can reduce the size of the antenna feeding network and improve its integration; the energy distribution of each antenna unit can be changed more easily by changing the angle of slot rotation, thereby reducing the side lobes of the antenna array and improving the detection accuracy.

[0028] Fourth, the millimeter-wave single-pulse filter array antenna based on gap waveguide and differential network feeding of the present invention combines the filter antenna with the single-pulse antenna, and has the frequency selection performance of the filter antenna and the high-precision characteristics of the single-pulse antenna, and has the advantages of multi-function and high integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A three-dimensional schematic diagram of a millimeter-wave single-pulse filter array antenna based on gap waveguide and difference network feeding proposed in the present invention;

[0030] Figure 2 A three-dimensional schematic diagram of a SIW filter antenna array composed of a microstrip multilayer board structure loaded with metal vias and surface slots according to the present invention;

[0031] Figure 3 A side view of a SIW filter array antenna composed of a microstrip multilayer board structure loaded with metal vias and surface slots according to the present invention and a schematic diagram of the stacked structure dimensions;

[0032] Figure 4 A top view and dimension diagram of the metal layer 1 of the SIW filter array antenna;

[0033] Figure 5 It is a top view and dimension diagram of metal layers 2 and 3 of the SIW filter array antenna;

[0034] Figure 6 A top view and dimension diagram of the metal layer 4 of the SIW filter array antenna;

[0035] Figure 7 A top view and dimension diagram of the metal layer 5 of the SIW filter array antenna;

[0036] Figure 8 A top view and dimension diagram of the metal through hole 6 of the SIW filter array antenna;

[0037] Figure 9 A top view and dimension diagram of the metal through hole 7 of the SIW filter array antenna;

[0038] Figure 10 3D schematic diagram of a GWG and difference network structure composed of metal plates with square pins according to the present invention (the T metal plate 13 is hidden for clarity);

[0039] Figure 11 A side view of a GWG sum-difference network structure composed of metal plates with square pins 12 according to the present invention and a schematic diagram of the dimensions of the GWG unit;

[0040] Figure 12 It is a top view and dimension diagram of the GWG and difference network T metal plate 13;

[0041] Figure 13 It is a top view and dimension diagram of the GWG and difference network M metal plate 14;

[0042] Figure 14 A top view of the GWG and difference network B metal plate 15;

[0043] Figure 15 It is a top view and dimensioning diagram of the upper structure of the GWG and difference network;

[0044] Figure 16 It is a top view and dimensioning diagram of the GWG and difference network lower structure;

[0045] Figure 17 This is a schematic diagram of the simulation results of the gain-frequency curve of the single-pulse filter array antenna;

[0046] Figure 18 The figure is a schematic diagram of the simulation results of the horizontal dimension and beam pattern of the monopulse filter array antenna;

[0047] Figure 19This is a schematic diagram of the simulation results of the horizontal dimension difference beam pattern of the single pulse filter array antenna;

[0048] Figure 20 This is a schematic diagram of the simulation results of the elevation-dimension pattern of the single-pulse filter array antenna;

[0049] Figure 21 This is a three-dimensional exploded view of the millimeter-wave single-pulse filter array antenna based on gap waveguide and difference network feeding of the present invention. DETAILED DESCRIPTION

[0050] The embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0051] The three-dimensional structure of the millimeter wave single pulse filtering antenna based on gap waveguide and differential network feeding designed by the present invention is as follows Figure 1 As shown in FIG, the monopulse antenna structure includes two parts: a SIW filter antenna array composed of metal vias and surface slots loaded on a microstrip multilayer board structure, and a GWG sum-difference network structure composed of a metal plate with square pins.

[0052] See also Figure 21The SIW filtering antenna array is composed of three dielectric substrates (referred to as T substrate 8, M substrate 9 and B substrate 10 respectively) with metal layers covering the upper, middle and lower surfaces, and a layer of semi-cured sheet 11. The metal via 6 passes through the T substrate 8, M substrate 9 and semi-cured sheet 10, and together with the metal layers 1, 2, 3, and 4 on the upper and lower surfaces of the T substrate 8 and the M substrate 9, constitute the antenna's last two resonant cavities; the metal via 7 is located in the B substrate 10, and together with the metal layers 4 and 5 on the upper and lower surfaces of the B substrate 10, constitute the antenna's feeding path and first-level cavity. The antenna unit of the present invention is composed of three resonant cavities, one horizontal (first-level resonant cavity) and two vertical (second and third-level resonant cavities), which are fed through the SIW transmission structure and achieve filtering performance by coupling between the cavities. Specifically, energy is coupled into the cavity through a slot on the metal layer 5 on the lower surface of the B substrate 10. After transmitting through the feed path and the primary cavity formed by the B substrate 10 and its upper and lower metal layers 4 and 5 and the metal via 6, it enters the secondary resonant cavity formed by the M substrate 9 and its upper and lower metal layers 3 and 4 and the metal via 6 through a coupling slot on the metal layer 4 on the upper surface of the B substrate 10. It then passes through a coupling slot on the metal layer 3 on the upper surface of the M substrate 9 and the metal layer 2 on the lower surface of the T substrate 8 and enters the tertiary resonant cavity formed by the T substrate 8 and its upper and lower metal layers 1 and 2 and the metal via 6. Finally, it radiates into free space through a slot on the metal layer 1 on the upper surface of the T substrate 8. The operating frequency of the present invention can be designed to be in the millimeter wave band. The dielectric substrates used are all Rogers 4350B, with relevant electrical parameters of εr=3.66, tanδ=0.0037, and the thickness of all dielectric substrates is 0.254mm; the prepreg used is Rogers RO4450F, with relevant electrical parameters of εr=3.52, tanδ=0.004, and the thickness after pressing is 0.1mm.

[0053] The GWG sum-difference network consists of three layers of metal plates (referred to as the T metal plate 13, the M metal plate 14, and the B metal plate 15) with square metal pins 12 on the top, middle, and bottom. The two layers of metal plates and the pins form a GWG unit. Their periodic arrangement can suppress the propagation of electromagnetic waves at specific frequencies and can be used to construct waveguide structures. The square pins on the bottom surface of the T metal plate 13 and the square pins on the top surface of the M metal plate 14 form the upper layer of the GWG sum-difference network, while the square pins 12 on the bottom surface of the M metal plate 14 and the square pins on the top surface of the B metal plate 15 form the lower layer of the GWG sum-difference network. The space between the two layers of metal plates is filled with air. The lower layer of the GWG sum-difference network has two input ports: sum and difference. After energy is fed into the sum port or the difference port, it is transmitted in the lower layer feed network, enters the upper layer feed network through the coupling slot on the M metal plate 14, and then couples into the microstrip antenna array through the slot on the top surface of the T metal plate 13. The GWG sum-difference network of the present invention can be designed to operate in a frequency band that matches the upper antenna array. The slots in the T-shaped metal plate 13 correspond one-to-one with the slots in the metal layer 5, and the slots in the T-shaped metal plate 13 are slightly larger than those in the metal layer 5. The metal pins 12 are arranged in a regular pattern, and electromagnetic waves are transmitted in the waveguide structure enclosed by the pins.

[0054] like Figure 1 Figure 2 shows a three-dimensional schematic diagram of a millimeter-wave monopulse filter antenna based on a gap waveguide and differential network feed, according to the present invention. This monopulse antenna structure consists of two components: a SIW filter antenna array constructed with metal vias and surface slots in a microstrip multilayer board structure, and a GWG and differential network structure consisting of a metal plate with square pins. The antenna measures 110.2 mm in length along the y-axis and 81.2 mm in length along the x-axis.

[0055] like Figure 2 and Figure 3 The figures show a three-dimensional schematic diagram, a side view, and dimension annotations of a SIW filter antenna array constructed by loading metal vias and surface slots on a microstrip multilayer board structure according to the present invention. The filter antenna array comprises a dielectric substrate with three metal layers (top, middle, and bottom) and a prepreg. Metal holes are loaded into the dielectric substrate and the prepreg to form the antenna's resonant cavity, and slots are loaded into the metal layer to achieve coupling between the cavities and antenna radiation. Specific structural parameters are: the thickness of the three dielectric substrates is 0.254 mm, the thickness of the prepreg is 0.1 mm, and the thickness of the metal layers is 0.5 oz.

[0056] like Figure 4Figure 1 shows a top view and dimensioning of metal layer 1 in the SIW filter antenna array. This layer is the antenna radiating layer. As shown in the figure, the double slits form a radiating element of the antenna. Thirty-two antenna elements are arranged in a 2×16 layout to form the antenna array, with a spacing of 6 mm. Each slit in the antenna element is 2.8 mm long and 0.35 mm wide, with a spacing of 1.59 mm between the two slits.

[0057] like Figure 5 Figure 2 shows a top view and dimensioning of metal layers 2 and 3 in the SIW filter antenna array. These two layers are coupling slot layers, through which electromagnetic energy enters the tertiary resonant cavity from the secondary resonant cavity. The coupling slots are also arranged in a 2×16 pattern, centered along the y-axis between the two radiating slots, with a length of 2.85 mm and a width of 0.25 mm.

[0058] like Figure 6 Figure 4 shows a top view and dimensioning of metal layer 4 in the SIW filter antenna array. This layer is the coupling slot layer, through which electromagnetic energy enters the secondary resonant cavity from the primary resonant cavity. The coupling slots are arranged in a 2×16 pattern, with a spacing of 6 mm in the y-axis and 9.58 mm in the x-axis. They are 2.85 mm long and 0.25 mm wide.

[0059] like Figure 7 Figure 5 shows a top view and dimensioning of metal layer 5 in the SIW filter antenna array. This layer is the coupling slot layer, through which electromagnetic energy enters the SIW feed structure and primary resonant cavity at the bottom layer of the multilayer board from the GWG and difference network. The coupling slots are arranged in a 2×16 pattern, with a spacing of 6mm along the y-axis and a center-to-center spacing of 24mm along the x-axis. They are 3mm long and 0.25mm wide. The coupling slots are arranged at an angle, rotating 24° counterclockwise or clockwise around the x-axis. Adjacent slots along the y-axis rotate in opposite directions to ensure that the electromagnetic energy input to the antenna elements is in phase, and adjacent slots along the x-axis rotate in the same direction.

[0060] like Figure 8 Figure 2 shows a top view and dimensioned layout of metal pillars 6 within the dielectric substrate of the SIW filter antenna array. The metal pillars, with a radius r = 0.15 mm, extend from metal layer 1 to metal layer 4, passing through metal layers 2 and 3, dielectric substrates 8 and 9, and prepreg 11. These pillars are periodically arranged to form square cavities, serving as the secondary and tertiary resonant cavities of the antenna elements. These square cavities are arranged in a 2×16 pattern, with each cavity measuring 6 mm in the y-axis and 6.28 mm in the x-axis.

[0061] like Figure 9Figure 2 shows a top view and dimensioned layout of metal pillars 7 within the dielectric substrate of the SIW filter antenna array. The metal pillars, with a radius of r = 0.15 mm, extend from metal layer 4 to metal layer 5, passing through the dielectric substrate 10. These pillars are periodically arranged to form square cavities, which serve as the antenna unit's feed structure. The square cavities are arranged in a 2×16 pattern, each measuring 4.35 mm in the y-axis and 12.75 mm in the x-axis. The feed structure contains two metal holes spaced 2.1 mm apart, creating a cavity with a length of 6.3 mm in the x-axis, which serves as the antenna's primary resonant cavity.

[0062] like Figure 10 and Figure 11 The following are a three-dimensional schematic diagram, side view, and dimension annotation of a GWG sum-difference network structure composed of metal plates with square pins according to the present invention. The GWG sum-difference network structure consists of three layers of metal plates with square metal pins 12, the upper, middle, and lower layers. The upper and lower layers of metal plates and the protruding pins constitute a GWG unit. The periodic arrangement of the upper and lower layers of metal plates can suppress the propagation of electromagnetic waves at specific frequencies and can be used to construct a waveguide structure. The space between the two layers of metal plates is filled with air. For a clearer display, Figure 10 The upper metal plate is hidden in the image. Its specific structural parameters are: metal plate thickness 0.5mm, square metal pin height 1mm, side length 1.4mm, gap between the upper and lower pins 0.1mm, and side length of each GWG unit 2.8mm.

[0063] like Figure 12 Figure 1 shows a top view and dimensioning of the T-shaped metal plate 13 in the GWG and differential network structure. This layer is the coupling slot layer, through which electromagnetic energy enters the SIW feed structure and primary resonant cavity at the bottom layer of the multilayer board from the upper layer of the GWG and differential network. The coupling slots are arranged in a 2×16 pattern, with the slot centers corresponding to the slots on metal layer 5, with the same rotational direction and angle, and slightly larger length and width. The slots are spaced 6 mm apart in the y-axis direction and 24 mm apart in the x-axis direction, with a length of 3.5 mm and a width of 0.5 mm.

[0064] like Figure 13 Figure 1 shows a top view and dimensioned representation of the M metal plate 14 in the GWG sum and difference network structure. This layer is the coupling slot layer, through which electromagnetic energy enters the upper layer of the multi-GWG sum and difference network from the lower layer of the GWG sum and difference network. There are two types of coupling slots, two of each, which are used to couple the upper and lower layers of the network when energy is input from the sum port and the difference port, respectively. The coupling slot length of the sum port is 4.3mm and the width is 1.1mm; the coupling slot length of the difference port is 4.26mm and the width is 1.1mm.

[0065] like Figure 14 FIG. 1 is a top view of the B metal plate 15 in the GWG sum differential network structure. The metal plate is a component of the lower transmission structure in the GWG sum differential network and has no loading gap treatment.

[0066] like Figure 15 Figure 2 shows a top view and dimensioning of the upper transmission structure in the GWG sum-difference network structure. This structure, composed of periodically arranged GWG units, can be divided into two symmetrical upper and lower sections, each consisting of a T-shaped power splitter and a folded angle structure. The sum port coupling slot is located at the end of the folded angle, while the difference port coupling slot is located in the middle of the T-shaped power splitter. After energy is coupled from the lower transmission structure into the upper layer, it passes through the T-shaped power splitter and enters the antenna array through the slots in the T-metal plate 13 and metal layer 5.

[0067] like Figure 16 Figure 1 shows a top view and dimensioned representation of the lower transmission structure in the GWG sum-difference network. This structure consists of periodically arranged GWG units and can be divided into two sections, each with an input port: the left side is the sum port and the right side is the difference port. Energy input through the sum / difference ports enters the upper transmission structure of the GWG sum-difference network through the coupling slots in the M metal plate 13.

[0068] like Figure 17 As shown in FIG, the gain curve simulation result of the single pulse filter antenna is shown. It can be observed that the in-band gain of the antenna reaches 20dBi and the out-of-band suppression exceeds -35dB.

[0069] like Figure 18 As shown in FIG, the simulation results of the horizontal dimension and beam pattern of the single pulse filter antenna at 35 GHz frequency.

[0070] like Figure 19 As shown in FIG, the simulation results of the horizontal dimensional difference beam pattern of the single pulse filter antenna at 35 GHz frequency.

[0071] like Figure 20 As shown in FIG, it is the simulation result of the elevation direction pattern of the single pulse filter antenna at the frequency of 35 GHz.

[0072] The present invention relates to a millimeter-wave single-pulse filter array antenna based on a gap waveguide (GWG) and differential network feeding. The single-pulse antenna structure comprises two parts: a substrate integrated waveguide (SIW) filter antenna array composed of metal vias loaded in a microstrip multilayer structure and slots loaded in a metal layer, and a GWG and differential network structure composed of a metal plate with square pins. The present invention realizes a slot filter antenna with a third-order SIW cavity by drilling holes in the antenna dielectric substrate and opening slots in the metal layer. Furthermore, a GWG transmission structure is formed by corresponding upper and lower metal plates with square pins, and a magic T structure is formed by coupling between the two layers of GWG to form a sum and differential feeding network. Finally, the sum and differential network is connected to the slot antenna to form a sum and differential beam, thereby forming a single-pulse filter antenna operating in the millimeter-wave frequency band. Compared with existing antenna arrays, the present invention combines a filtering antenna with a single-pulse antenna, and has both the frequency selection characteristics of a filtering antenna and the high-precision target positioning characteristics of a single-pulse antenna. It has the advantages of high integration and multi-functions, and can be applied to target detection in the millimeter wave frequency band.

[0073] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0074] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0075] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0076] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions for executing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0077] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0078] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding, characterized in that: The millimeter wave single pulse filter array antenna includes a SIW filter antenna array composed of metal vias and metal layer slots loaded on a microstrip multilayer board structure and a GWG sum-difference network structure composed of a metal plate with square pins; The GWG sum-difference network structure consists of three layers of metal plates with square metal pins. The space between two adjacent metal plates is filled with air. The two adjacent metal plates and the protruding pins form a GWG unit. Electromagnetic waves are transmitted in the waveguide structure surrounded by the pins. After energy is fed into the sum port or difference port, it passes through the two-layer feeding network and is coupled into the SIW filter antenna array through the slots loaded on the surface of the metal plate. The SIW filter antenna array is composed of three dielectric substrates covered with metal layers and a prepreg. Metal holes are added in the dielectric substrate and the prepreg to form the antenna's resonant cavity, and slots are added in the metal layer to achieve coupling between the cavities and antenna radiation. The energy is coupled into the cavity through the gaps on the metal layer on the lower surface of the lowest dielectric substrate, and after being transmitted through the resonant cavity, it is radiated into the free space through the gaps on the metal layer on the upper surface of the highest dielectric substrate.

2. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 1, characterized in that: The operating frequencies of the SIW filter antenna array and the GWG sum-difference network structure match each other, and both operate in the millimeter wave frequency band.

3. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 1, characterized in that: The gaps loaded by the top metal plate correspond one to one with the gaps loaded by the metal layer below the bottom dielectric substrate, and the size of the gaps loaded by the top metal plate is larger than the size of the gaps loaded by the metal layer below the bottom dielectric substrate.

4. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 1, characterized in that: The SIW filter antenna array is formed by stacking a first dielectric substrate, a prepreg, a second dielectric substrate, and a third dielectric substrate, wherein the surfaces of the first dielectric substrate, the second dielectric substrate, and the third dielectric substrate are covered with a metal layer; a first metal via passes through the first dielectric substrate, the prepreg, and the second dielectric substrate, and together with the metal layers on the upper and lower surfaces of the first and second dielectric substrates, forms a secondary resonant cavity and a tertiary resonant cavity of the antenna; a second metal via is located in the third dielectric substrate, and together with the metal layers on the upper and lower surfaces of the third dielectric substrate, forms a feeding path and a primary resonant cavity of the antenna; Energy is coupled into the cavity through the slots loaded on the metal layer on the lower surface of the third dielectric substrate, and after being transmitted in the feed path and the first-level resonant cavity composed of the third dielectric substrate and the metal layers on its upper and lower surfaces and the metal vias, enters the second-level resonant cavity composed of the second dielectric substrate and its upper and lower surface metal layers and the metal vias through the coupling slots loaded on the metal layer on the upper surface of the third dielectric substrate, and then enters the third-level resonant cavity composed of the first dielectric substrate and the metal vias on its upper and lower surface metal layers through the coupling slots loaded on the metal layer on the upper surface of the second dielectric substrate and the metal layer on the lower surface of the first dielectric substrate, and finally radiates into free space through the slots loaded on the metal layer on the upper surface of the first dielectric substrate.

5. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 4, characterized in that: The SIW filter antenna array is composed of 32 antenna elements connected in series in a 2×16 layout.

6. The millimeter wave monopulse filter array antenna based on gap waveguide and difference network feeding according to claim 5, characterized in that: The metal layer on the upper surface of the first dielectric substrate is an antenna radiation layer, and a plurality of slots are provided above the metal layer. Every two slots constitute a radiation unit of the antenna, and 32 radiation units are arranged in a 2×16 layout to form an antenna array; The metal layer on the lower surface of the first dielectric substrate and the metal layer on the upper surface of the second dielectric substrate serve as first coupling slot layers, through which electromagnetic energy enters the third resonant cavity from the secondary resonant cavity; the first coupling slots are arranged in a 2×16 layout; The metal layer on the lower surface of the second dielectric substrate is a second coupling slot layer, and electromagnetic energy enters the secondary resonant cavity from the primary resonant cavity through the second coupling slots, and the second coupling slots are arranged in a 2×16 layout; The metal layer on the lower surface of the third dielectric substrate is a third coupling slot layer. Electromagnetic energy enters the SIW feeding structure and the first-order resonant cavity at the bottom layer of the SIW filter antenna array from the GWG sum-difference network structure through the third coupling slots. The third coupling slots are arranged in a 2×16 layout; wherein the third coupling slots are arranged obliquely, with the direction being counterclockwise or clockwise rotated at a preset angle based on the x-axis direction, and adjacent slots in the y-axis direction rotate in opposite directions, so that the electromagnetic energy input to the antenna unit is in phase, and adjacent slots in the x-axis direction rotate in the same direction.

7. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 1, characterized in that: The GWG sum-difference network structure includes a first metal plate with square metal pins, a second metal plate, and a third metal plate stacked together. The square pins on the lower surface of the first metal plate and the square pins on the upper surface of the second metal plate constitute an upper-layer GWG sum-difference network, while the square pins on the lower surface of the second metal plate and the square pins on the upper surface of the third metal plate constitute a lower-layer GWG sum-difference network. The space between the two metal plates is filled with air. The lower-layer GWG sum-difference network has two input ports, sum and difference. After energy is fed into the sum port or the difference port, it passes through the two-layer feeding network and is coupled into the microstrip antenna array through the slot loaded on the upper surface of the first metal plate.

8. The millimeter wave single pulse filter array antenna based on gap waveguide and difference network feeding according to claim 7, characterized in that: The GWG sum difference network structure includes a middle and upper layer transmission structure and a middle and lower layer transmission structure; The upper-middle transmission structure is divided into two symmetrical upper and lower parts, each consisting of a T-shaped power splitter structure and a folded angle structure; the sum port coupling slot is located at the tail of the folded angle, and the difference port coupling slot is located in the middle of the T-shaped power splitter; after energy is coupled into the upper layer by the lower transmission structure, it passes through the T-shaped power splitter and enters the antenna array through the slots on the metal layer below the first metal plate and the bottom dielectric substrate; The middle and lower transmission structure is divided into two parts, left and right, each of which has an input port, with the left side being the sum port and the right side being the difference port; after the energy is input from the sum / difference port, it enters the upper transmission structure of the GWG sum and difference network structure through the coupling gap on the second metal plate.

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