Planar waveguide coaxial broadband dual-polarization antenna and co-aperture array antenna

Abstract

The present application provides a planar waveguide coaxial broadband dual-polarization antenna and a common aperture array antenna. The planar waveguide coaxial broadband dual-polarization antenna comprises: a bottom waveguide cavity for exciting high-frequency band signals, and a four-ridged waveguide assembly stacked on the bottom waveguide cavity for exciting low-frequency band signals; the four-ridged waveguide assembly is provided with two mutually perpendicular T-shaped microstrip branches to form mutually perpendicular dual-polarization modes, and the four-ridged waveguide assembly is also provided with planar waveguide coaxial lines respectively connected to the two T-shaped microstrip branches and perpendicular to each other for respectively performing dual-polarization excitation on low-frequency band signals. The planar waveguide coaxial broadband dual-polarization antenna provided by the present application has a compact structure and low loss, a wide impedance bandwidth and can realize dual polarization, and can be applied to dual-frequency common aperture.

Description

Technical Field

[0001] The present application relates to the field of antenna technology, and in particular to a planar waveguide coaxial broadband dual-polarization antenna and a co-aperture array antenna. Background Art

[0002] In recent years, the application of satellite communication system technology has developed rapidly, bringing unprecedented development opportunities for new antenna technologies and microwave / millimeter wave circuit technologies. However, they also face the challenges of the market's requirements for miniaturization, high integration, broadband, and other aspects. Dual-polarization is a widely used technology that can improve communication capacity and received signal quality within a given spectrum due to its ability to combat multipath fading. Microstrip lines and dielectric integrated waveguides (SIWs) are commonly used to realize dual-polarization antenna arrays. However, due to the high dielectric loss of the dielectric substrate, especially in the high microwave band, the efficiency and gain of these antennas are often limited.

[0003] Currently, most existing waveguide dual-polarization array antennas use cross-shaped slots, square slots, or magnetoelectric dipoles to achieve dual polarization. To facilitate the layout of the feed network, all of these works use a one-to-four back cavity to excite the 2×2 subarray. Considering grating lobe suppression, the period between array elements in the relevant plane should be minimized, resulting in a narrow achievable operating bandwidth. Therefore, achieving broadband dual-polarization antennas is particularly important for satellite communication applications. Planar coaxial waveguides have high Q factors and low loss. Due to their coaxial characteristics and the propagation of TEM modes, they have greater potential for miniaturization while ensuring low loss.

[0004] With the rapid development of satellite communication technology, high capacity and high speed have become future requirements. This requires the development of new satellite communication systems, the establishment of multi-band satellite communication networks, and the development of new frequency bands (such as the Ka band) to increase data transmission speeds. Currently, dual-frequency, dual-polarization, co-aperture technology is a key development direction for satellite communication antennas. It can expand communication capacity, achieve multi-purpose use of a single station, and significantly reduce costs. Summary of the Invention

[0005] In view of this, embodiments of the present application provide a planar waveguide coaxial broadband dual-polarization antenna and a co-aperture array antenna to eliminate or improve one or more defects in the prior art.

[0006] One aspect of the present application provides a planar waveguide coaxial broadband dual-polarization antenna, comprising: a bottom waveguide cavity for exciting high-frequency band signals, and a four-ridged waveguide component stacked on the bottom waveguide cavity for exciting low-frequency band signals;

[0007] The quad-ridged waveguide component is provided with two mutually perpendicular T-shaped microstrip branches to form mutually perpendicular dual-polarization modes. The quad-ridged waveguide component is also provided with planar waveguide coaxial lines that are respectively connected to the two T-shaped microstrip branches one by one and perpendicular to each other for respectively performing dual-polarization excitation on the low-frequency band signals.

[0008] In some embodiments of the present application, the quad-ridged waveguide assembly includes: a first quad-ridged waveguide cavity, a first dielectric substrate, a second quad-ridged waveguide cavity, a second dielectric substrate, a third quad-ridged waveguide cavity, and a third dielectric substrate stacked in sequence;

[0009] Between the first quad-ridged waveguide cavity and the first dielectric substrate, and between the second quad-ridged waveguide cavity and the second dielectric substrate, a T-shaped microstrip branch and a planar waveguide coaxial line are provided which are perpendicular and connected to each other;

[0010] A cross-shaped patch group is provided between the third quad-ridged waveguide cavity and the third dielectric substrate to suppress grating lobes and increase gain;

[0011] The first quad-ridged waveguide cavity is stacked on the bottom waveguide cavity.

[0012] In some embodiments of the present application, a first T-shaped microstrip branch and a first planar waveguide coaxial line are provided on one side of the first quad-ridged waveguide cavity close to the first dielectric substrate, and the first planar waveguide coaxial line serves as a first input port of the planar waveguide coaxial broadband dual-polarization antenna to perform horizontally polarized excitation on Ku-band signals.

[0013] The height of the first quad-ridged waveguide cavity is initially set to a quarter wavelength of a preset operating frequency;

[0014] When the first input port is excited, the input signal is converted to the TE mode of the first quad-ridged waveguide cavity through the TEM mode in the first planar waveguide coaxial line. 001 mode, and controlling the energy coupling from the first planar waveguide coaxial line to the first quad-ridged waveguide cavity by adjusting the length of the first T-type microstrip branch to achieve horizontally polarized radiation.

[0015] In some embodiments of the present application, a second T-shaped microstrip branch and a second planar waveguide coaxial line are provided on one side of the second quad-ridged waveguide cavity close to the second dielectric substrate, the second T-shaped microstrip branch and the first T-shaped microstrip branch are perpendicular to each other, the first planar waveguide coaxial line and the second planar waveguide coaxial line are perpendicular to each other, and the second planar waveguide coaxial line serves as the second input port of the planar waveguide coaxial broadband dual-polarization antenna to perform vertically polarized excitation on Ku-band signals;

[0016] The height of the second quadruple-ridged waveguide cavity is initially set to one-eighth of the wavelength of a preset operating frequency;

[0017] When the second input port is excited, the input signal is converted to the TE mode of the second quad-ridged waveguide cavity through the TEM mode in the second planar waveguide coaxial line. 010 mode, and controlling the energy coupling from the second planar waveguide coaxial line to the second quad-ridged waveguide cavity by adjusting the length of the second T-type microstrip branch to achieve vertically polarized radiation.

[0018] In some embodiments of the present application, the bottom waveguide cavity includes: a square waveguide cavity;

[0019] A third input port is provided in the square waveguide cavity; the third input port is used to excite Ka-band signals and expand into an input port of another millimeter-wave band antenna.

[0020] In some embodiments of the present application, the planar waveguide coaxial line comprises: an upper waveguide, a lower waveguide, and an intermediate dielectric substrate arranged in sequence;

[0021] A suspended microstrip line is coaxially provided on one side of the intermediate dielectric substrate close to the lower waveguide;

[0022] The upper waveguide and the lower waveguide are both filled with air to form an outer conductor; the suspended microstrip line forms an inner conductor of the planar waveguide coaxial line at the center of the outer conductor.

[0023] In some embodiments of the present application, the cross-shaped patch group comprises: four cross-shaped patches;

[0024] Each of the cross-shaped patches is printed on a side of the third dielectric substrate close to the third quadruple-ridged waveguide cavity and is located on the radiation aperture surface of the third quadruple-ridged waveguide cavity.

[0025] Another aspect of the present application further provides a co-aperture array antenna, comprising: a plurality of co-aperture and connected planar waveguide coaxial broadband dual-polarization antennas.

[0026] In some embodiments of the present application, the quad-ridged waveguide assembly includes: a first quad-ridged waveguide cavity, a first dielectric substrate, a second quad-ridged waveguide cavity, a second dielectric substrate, a third quad-ridged waveguide cavity, and a third dielectric substrate stacked in sequence; between the first quad-ridged waveguide cavity and the first dielectric substrate, and between the second quad-ridged waveguide cavity and the second dielectric substrate, a T-shaped microstrip branch and a planar waveguide coaxial line that are perpendicular and connected to each other are provided;

[0027] The first quad-ridged waveguide cavity in each of the planar waveguide coaxial broadband dual-polarization antennas and each T-shaped microstrip branch between the first dielectric substrate are connected based on a preset first feeding network;

[0028] The second quad-ridged waveguide cavity in each of the planar waveguide coaxial broadband dual-polarization antennas and each T-shaped microstrip branch between the second dielectric substrate are connected based on a preset second feeding network.

[0029] In some embodiments of the present application, the first feeding network and the second feeding network are both hybrid structures combining series and parallel connections;

[0030] Feed delay lines are provided in both the first feeding network and the second feeding network to ensure that the phases of the units excited in series are consistent.

[0031] The planar waveguide coaxial broadband dual-polarized antenna provided by the present application adopts a planar waveguide coaxial line as the feeding structure of the broadband dual-polarized antenna. The planar waveguide coaxial line has broadband characteristics, not only has the advantages of low loss and miniaturization, but also because the coaxial line has no cut-off frequency, the size is not limited by frequency, so it has better advantages in designing large-scale array antennas; by adopting a four-ridged waveguide cavity component as the main cavity of the entire antenna, and by setting two mutually perpendicular T-shaped microstrip branches in the main cavity to achieve the energy coupling of the TEM mode of the plane waveguide coaxial line and the four-ridged waveguide cavity, thereby obtaining two mutually perpendicular polarization modes; in addition, the use of the four-ridged waveguide component not only makes the antenna structure more compact, but also expands the bandwidth of the antenna; by setting a bottom waveguide cavity at the bottom of the antenna that can be expanded to the input port of another millimeter wave band antenna, multiple polarizations can be achieved in a compact structure. In other words, the planar waveguide coaxial broadband dual-polarized antenna provided by the present application has a compact structure and low loss, a wide impedance bandwidth and can achieve dual polarization, and can be applied to dual-frequency common aperture.

[0032] Additional advantages, purposes, and features of the present application will be described in part in the following description and will become apparent to those skilled in the art upon study of the following or may be learned from practice of the present application. The purposes and other advantages of the present application may be achieved and obtained by the structures specifically pointed out in the specification and drawings.

[0033] Those skilled in the art will understand that the purposes and advantages that can be achieved by the present application are not limited to the above specific description, and the above and other purposes that can be achieved by the present application will be more clearly understood based on the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are intended to provide a further understanding of the present application, constitute a part of the present application, and do not constitute a limitation of the present application. The components in the drawings are not drawn to scale, but are only for the purpose of illustrating the principles of the present application. In order to facilitate the illustration and description of some parts of the present application, the corresponding parts in the drawings may be enlarged, that is, they may become larger than other components in the exemplary device actually manufactured according to the present application. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of the planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application.

[0036] Figure 2 This is a schematic structural diagram of the planar waveguide coaxial line provided in an embodiment of the present application.

[0037] Figure 3 This is a schematic diagram of the example structure of a 2*2 common-aperture array antenna provided in an embodiment of the present application.

[0038] Figure 4 Schematic diagram of antenna return loss.

[0039] Figure 5 Schematic diagram of antenna isolation.

[0040] Figure 6 Schematic diagram of the two orthogonal mode return losses of the third input port.

[0041] FIG7( a ) is a schematic diagram showing the direction of the first input port.

[0042] FIG7( b ) is a schematic diagram showing the direction of the second input port.

[0043] Figure Number:

[0044] 1. The first quad-ridge waveguide cavity;

[0045] 2. The second quad-ridge waveguide cavity;

[0046] 3. The third and fourth ridge waveguide cavity;

[0047] 4. Bottom waveguide cavity;

[0048] 5. a first dielectric substrate;

[0049] 6. A second dielectric substrate;

[0050] 7. The third dielectric substrate;

[0051] 8. First input port;

[0052] 9. Second input port;

[0053] 10. The third input port;

[0054] 11. Cross-shaped patch group;

[0055] 12. The first T-type microstrip branch;

[0056] 13. Second T-type microstrip branch;

[0057] 21. Lower waveguide;

[0058] 22. Upper waveguide;

[0059] 23. Intermediate dielectric substrate;

[0060] 24. Suspended microstrip line;

[0061] 31. First feeding network;

[0062] 32. Second feeding network;

[0063] 33. Feed delay line;

[0064] ①, the T-shaped microstrip branches inside the upper layer of the second feeding network 32;

[0065] ②, the T-shaped microstrip branches outside the upper layer of the second feeding network 32;

[0066] ③. T-type microstrip branches inside the lower layer of the second feeding network 32;

[0067] ④. The T-type microstrip branch outside the lower layer in the second feeding network 32. DETAILED DESCRIPTION

[0068] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail in conjunction with the embodiments and drawings. Here, the illustrative embodiments of this application and their descriptions are used to explain this application, but are not intended to limit this application.

[0069] It should also be noted here that in order to avoid obscuring the present application due to unnecessary details, the accompanying drawings only show structures and / or processing steps that are closely related to the scheme according to the present application, while other details that are not closely related to the present application are omitted.

[0070] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0071] It should be emphasized that the term "include / comprises" when used herein refers to the existence of features, elements, steps or components, but does not exclude the existence or addition of one or more other features, elements, steps or components.

[0072] It should also be noted that, unless otherwise specified, the term "connection" herein may refer not only to a direct connection but also to an indirect connection involving an intermediate.

[0073] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0074] In response to the problems that the insertion loss of existing microstrip dual-polarization antennas is too large and the bandwidth of waveguide dual-polarization antennas is relatively narrow, the present application provides embodiments of a planar waveguide coaxial broadband dual-polarization antenna and a common-aperture array antenna, which have compact structure, low loss, wide impedance bandwidth, can realize dual polarization, and can be applied to dual-frequency common-aperture antenna design. A planar waveguide coaxial line is used as the feeding structure of the broadband dual-polarization antenna, and a four-ridged waveguide cavity is used as the main cavity of the entire antenna. The two mutually perpendicular T-shaped microstrip branches in the main cavity realize the energy coupling between the TEM mode of the waveguide coaxial structure and the four-ridged waveguide cavity, thereby obtaining two mutually perpendicular polarization modes. The planar waveguide coaxial structure has broadband characteristics. In addition, the use of a four-ridged waveguide structure not only makes the antenna structure more compact, but also expands the bandwidth of the antenna. The square waveguide cavity at the bottom of the antenna can be expanded to be the input port of another millimeter-wave band antenna, so that multiple polarizations can be achieved in a compact structure.

[0075] The details are described in detail through the following examples.

[0076] In order to design an antenna with a compact structure, low loss, wide impedance bandwidth, and dual-polarization capability, and applicable to dual-frequency common aperture, the present application provides a planar waveguide coaxial broadband dual-polarization antenna. The planar waveguide coaxial broadband dual-polarization antenna specifically includes the following:

[0077] A bottom waveguide cavity is used to excite high-frequency band signals, and a four-ridged waveguide component stacked on the bottom waveguide cavity is used to excite low-frequency band signals; by setting a bottom waveguide cavity at the bottom of the antenna that can be expanded into the input port of another millimeter-wave band antenna, multiple polarizations can be achieved in a compact structure.

[0078] The four-ridged waveguide component is provided with two mutually perpendicular T-shaped microstrip branches to form mutually perpendicular dual-polarization modes. The four-ridged waveguide component is also provided with planar waveguide coaxial lines that are respectively connected to the two T-shaped microstrip branches and are mutually perpendicular to each other for respectively performing dual-polarization excitation on the low-frequency band signals. Among them, by adopting the planar waveguide coaxial line as the feeding structure of the broadband dual-polarization antenna, the planar waveguide coaxial line has broadband characteristics, not only has the advantages of low loss and miniaturization, but also because the coaxial line has no cut-off frequency and its size is not limited by frequency, it has better advantages in designing large-scale array antennas. By adopting the four-ridged waveguide cavity component as the main cavity of the entire antenna, and by setting two mutually perpendicular T-shaped microstrip branches in the main cavity to realize the energy coupling of the TEM mode of the plane waveguide coaxial line and the four-ridged waveguide cavity, two mutually perpendicular polarization modes are obtained; in addition, the use of the four-ridged waveguide component not only makes the antenna structure more compact, but also expands the bandwidth of the antenna.

[0079] It can be understood that the planar waveguide coaxial broadband dual-polarization antenna provided in the present application is composed of a waveguide structure and an easily processable planar microstrip line, has a simple structure, and a flexible and simple design method.

[0080] In order to further improve the application reliability and structural compactness of the quad-ridged waveguide assembly, in a planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application, see Figure 1 The quad-ridged waveguide component in the planar waveguide coaxial broadband dual-polarization antenna specifically includes the following contents:

[0081] A first quad-ridged waveguide cavity 1, a first dielectric substrate 5, a second quad-ridged waveguide cavity 2, a second dielectric substrate 6, a third quad-ridged waveguide cavity 3 and a third dielectric substrate 7 stacked in sequence;

[0082] Between the first quadruple-ridged waveguide cavity 1 and the first dielectric substrate 5, and between the second quadruple-ridged waveguide cavity 2 and the second dielectric substrate 6, there are T-shaped microstrip branches and planar waveguide coaxial lines that are perpendicular and connected to each other;

[0083] A cross-shaped patch group 11 is provided between the third quad-ridged waveguide cavity 3 and the third dielectric substrate 7 to suppress grating lobes and increase gain;

[0084] The first quad-ridged waveguide cavity 1 is stacked on the bottom waveguide cavity 4 .

[0085] That is to say, the overall structure of the planar waveguide coaxial broadband dual-polarization antenna includes: three quad-ridged waveguide cavities, two planar waveguide coaxial lines, a three-layer dielectric substrate, a group of cross-shaped patch groups 11 and a bottom waveguide cavity 4 located at the bottom of the entire antenna.

[0086] In order to further improve the application reliability and structural compactness of the first quad-ridged waveguide cavity 1, in a planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application, see Figure 1 A first T-shaped microstrip branch 12 and a first planar waveguide coaxial line are provided on one side of the first quad-ridged waveguide cavity 1 close to the first dielectric substrate 5, and the first planar waveguide coaxial line serves as the first input port 8 of the planar waveguide coaxial broadband dual-polarized antenna to perform horizontal polarization excitation on the Ku-band signal.

[0087] The height of the first quadruple-ridged waveguide cavity 1 is initially set to a quarter wavelength of a preset operating frequency;

[0088] When the first input port 8 is excited, the input signal is converted to the TE mode of the first quad-ridged waveguide cavity 1 through the TEM mode in the first planar waveguide coaxial line. 001 mode, by adjusting the length of the first T-type microstrip branch 12 to control the energy coupling from the first planar waveguide coaxial line to the first quad-ridged waveguide cavity 1 to achieve horizontally polarized radiation.

[0089] In order to further improve the application reliability and structural compactness of the second quad-ridged waveguide cavity 2, in a planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application, see Figure 1 A second T-shaped microstrip branch 13 and a second planar waveguide coaxial line are provided on one side of the second quad-ridged waveguide cavity 2 close to the second dielectric substrate 6, which are perpendicular to and connected to each other. The second T-shaped microstrip branch 13 and the first T-shaped microstrip branch 12 are perpendicular to each other, and the first planar waveguide coaxial line and the second planar waveguide coaxial line are perpendicular to each other. The second planar waveguide coaxial line serves as the second input port 9 of the planar waveguide coaxial broadband dual-polarized antenna to perform vertically polarized excitation on the Ku-band signal.

[0090] The height of the second quadruple-ridged waveguide cavity 2 is initially set to one eighth of the wavelength of the preset operating frequency;

[0091] When the second input port 9 is excited, the input signal is converted to the TE mode of the second quad-ridged waveguide cavity 2 through the TEM mode in the second planar waveguide coaxial line. 010 mode, by adjusting the length of the second T-type microstrip branch 13 to control the energy coupling from the second planar waveguide coaxial line to the second quad-ridged waveguide cavity 2 to achieve vertically polarized radiation.

[0092] In order to further improve the application reliability and structural compactness of the bottom waveguide cavity 4, in a planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application, see Figure 1 , the bottom waveguide cavity 4 is specifically a square waveguide cavity;

[0093] A third input port 10 is provided in the square waveguide cavity; the third input port 10 is used to excite a Ka-band signal and expand it into an input port of another millimeter-wave band antenna.

[0094] Specifically, the bottom waveguide cavity 4 is a smaller square waveguide structure located at the bottom of the quad-ridged waveguide cavity assembly and serves as the input port of another millimeter wave frequency band antenna, namely, the third input port 10 .

[0095] That is to say, the overall structure of the planar waveguide coaxial broadband dual-polarization antenna has three input ports. The two planar coaxial waveguide ports excite horizontal polarization and vertical polarization respectively, namely the first input port 8 and the second input port 9. The port of the square waveguide cavity at the bottom is the high-frequency input port, namely the third input port 10. The quad-ridged waveguide cavity is divided into three layers of waveguide structure processing, namely: the first quad-ridged waveguide cavity 1, the second quad-ridged waveguide cavity 2 and the third quad-ridged waveguide cavity 3. The height h1 of the first waveguide cavity is initially set to one-quarter wavelength of the operating frequency. The height h2 of the second waveguide cavity is initially set to one-eighth wavelength of the operating frequency. The three-layer dielectric substrate is the first dielectric substrate 5, the second dielectric substrate 6 and the third dielectric substrate 7 from bottom to top. Among them, the first dielectric substrate 5 and the second dielectric substrate 6 serve as carriers of vertical polarization and horizontal polarization feed lines.

[0096] In order to further improve the application reliability and structural compactness of the planar waveguide coaxial line, in a planar waveguide coaxial broadband dual-polarized antenna provided in an embodiment of the present application, see Figure 2 The planar waveguide coaxial line specifically includes the following contents:

[0097] The upper waveguide 22, the lower waveguide 21, the suspended microstrip line 24 and the intermediate dielectric substrate 23 are arranged in sequence.

[0098] A suspended microstrip line 24 is coaxially provided on one side of the intermediate dielectric substrate 23 close to the lower waveguide 21 .

[0099] The upper waveguide 22 and the lower waveguide 21 are both filled with air to form outer conductors; the suspended microstrip line 24 forms the inner conductor of the planar waveguide coaxial line at the center of the outer conductors.

[0100] Specifically, the planar coaxial waveguide line is composed of an inner conductor and an outer conductor. The outer conductor is composed of a square waveguide filled with air, and the inner conductor is a suspended microstrip line 24 located in the center, wherein the suspended microstrip line 24 is printed under the intermediate dielectric substrate 23. The two planar waveguide coaxial lines serve as the feeding structures of the broadband dual-polarization antenna, respectively, and are divided into a first feeding structure and a second feeding structure. The first feeding structure excites vertical polarization, and the second feeding structure excites horizontal polarization. The suspension line of the first feeding structure is printed under the first dielectric substrate 5, and both ends of the first planar waveguide coaxial line are connected to a T-type microstrip branch, namely the first T-type microstrip branch 12. The suspension line of the second feeding structure is printed under the second dielectric substrate 6, and the end of the second planar waveguide coaxial line is connected to a T-type microstrip branch, namely the second T-type microstrip branch 13.

[0101] In order to further improve the application reliability and effectiveness of the cross-shaped patch group 11, in a planar waveguide coaxial broadband dual-polarization antenna provided in an embodiment of the present application, the cross-shaped patch group 11 specifically includes four cross-shaped patches;

[0102] Each of the cross-shaped patches is printed on the third dielectric substrate 7 on a side close to the third quadruple-ridged waveguide cavity 3 and is located on the radiation aperture surface of the third quadruple-ridged waveguide cavity 3 .

[0103] That is to say, the four cross-shaped patches are all located above the third waveguide cavity and printed on the lower surface of the third dielectric substrate 7 .

[0104] Based on the planar waveguide coaxial broadband dual-polarization antenna provided in the above embodiment, the present application also provides an embodiment of a co-aperture array antenna, which specifically includes multiple co-aperture and connected planar waveguide coaxial broadband dual-polarization antennas mentioned in the above embodiment.

[0105] In order to further improve the structural compactness and application reliability of the co-aperture array antenna, in a co-aperture array antenna provided in an embodiment of the present application, each T-shaped microstrip branch between the first quad-ridged waveguide cavity 1 and the first dielectric substrate 5 in each of the planar waveguide coaxial broadband dual-polarization antennas is connected based on a preset first feeding network 31;

[0106] Each T-shaped microstrip branch between the second quad-ridged waveguide cavity 2 and the second dielectric substrate 6 in each of the planar waveguide coaxial broadband dual-polarization antennas is connected based on a preset second feeding network 32 .

[0107] In order to further improve the application reliability and effectiveness of the co-aperture array antenna, in a co-aperture array antenna provided in an embodiment of the present application, the first feeding network 31 and the second feeding network 32 are both a series-parallel hybrid structure; it can be understood that the above-mentioned series-parallel hybrid structure refers to a series and parallel hybrid structure, for example, see Figure 3 Taking a 2*2 common aperture array antenna as an example, the upper inner T-type microstrip branch ① of the second feeding network 32 and the upper outer T-type microstrip branch ② of the second feeding network 32 are connected in parallel, and the lower inner T-type microstrip branch ③ of the second feeding network 32 and the lower outer T-type microstrip branch ④ of the second feeding network 32 are also connected in parallel. The upper inner T-type microstrip branch ① of the second feeding network 32 and the lower inner T-type microstrip branch ③ of the second feeding network 32 are connected in series, and the upper outer T-type microstrip branch ② of the second feeding network 32 and the lower outer T-type microstrip branch ④ of the second feeding network 32 are also connected in series. A feeding delay line 33 is provided in both the first feeding network 31 and the second feeding network 32 to ensure that the phases of the series-excited units are consistent.

[0108] Specifically, the co-aperture array antenna's feed network uses series-parallel feeding. To maintain phase consistency between unit structures, 180-degree extension lines are placed between adjacent units, such as the first and second delay lines. These two delay lines are identical in size, approximately one wavelength in length within the operating frequency band.

[0109] The two sets of series-parallel feeding networks based on planar coaxial waveguides have the same structure and are placed vertically to realize vertical polarization and horizontal polarization feeding of the dual-polarization antenna array.

[0110] In order to facilitate the design of the array power division network, the characteristic impedance of the planar coaxial waveguide is 100 ohms. The size of the outer conductor cavity is W a , the width of the suspension line is W s .

[0111] When the first input port 8 is excited, the input signal is converted into the TE mode of the quad-ridged waveguide cavity through the TEM mode in the planar coaxial waveguide. 001 mode, by adjusting the length of the first T-shaped microstrip branch 12 to control the energy coupling from the planar coaxial waveguide line to the quad-ridged waveguide cavity, thereby achieving horizontally polarized radiation.

[0112] When the second input port 9 is excited, the input signal is converted to the TE mode of the quad-ridge waveguide cavity through the TEM mode in the planar coaxial waveguide. 010 mode, and the energy coupling from the planar coaxial waveguide line to the quad-ridged waveguide cavity is controlled by adjusting the length of the second T-shaped microstrip branch 13, thereby achieving vertically polarized radiation.

[0113] Based on this, the planar waveguide coaxial broadband dual-polarization antenna and co-aperture array antenna provided in the embodiments of the present application have the following beneficial technical effects:

[0114] 1) Planar waveguide coaxial lines offer advantages such as low loss and miniaturization. Since they have no cutoff frequency and their size is not limited by frequency, they are particularly advantageous in designing large-scale array antennas.

[0115] 2) Compact structure and easy processing. The antenna is composed of four waveguide layers and three dielectric substrate layers. The suspended microstrip line is printed on the dielectric substrate, making it easier to process than traditional coaxial lines.

[0116] 3) Wide operating bandwidth. The dual-polarized antenna's radiating cavity utilizes a quad-ridged waveguide structure. Compared to traditional square waveguides, this is not only more compact but also extends the antenna's operating frequency band. Furthermore, the planar waveguide coaxial line itself possesses broadband characteristics, making it easier to design broadband array antennas.

[0117] 4) This dual-polarized antenna can be used in dual-band, co-aperture antenna designs. Low-frequency excitation is achieved through a planar waveguide coaxial structure, while high-frequency excitation is achieved through a square waveguide cavity at the bottom, thereby achieving a more compact dual-band, co-aperture array antenna.

[0118] In order to further illustrate the planar waveguide coaxial broadband dual-polarized antenna and co-aperture array antenna provided by the above embodiment, the present application also provides a specific application example of the planar waveguide coaxial broadband dual-polarized antenna and co-aperture array antenna. In this application example, the waveguide material is aluminum, and the dielectric substrate is Roger RT5880, with a dielectric constant of 2.2 and a dielectric loss of 0.0009. The present application is implemented by combining waveguides and dielectric plates, and has the advantages of compact structure, low loss, and broadband performance that is better than traditional microstrip waveguides, and has broad application prospects. Specifically, the content of the specific application example of the planar waveguide coaxial broadband dual-polarized antenna is as follows:

[0119] See also Figure 1, the planar waveguide coaxial line is used for the broadband dual-polarization feed line of the first frequency band, and the waveguide cavity (third input port 10) at the bottom is designed as the input of the second frequency band. The first quad-ridged waveguide cavity 1, the second quad-ridged waveguide cavity 2 and the third quad-ridged waveguide cavity 3 serve as common resonant cavities for the two frequency bands. Among them, the first T-type microstrip branch 12 and the first dielectric substrate 5 are located between the first quad-ridged waveguide cavity 1 and the second quad-ridged waveguide cavity 2, the second T-type microstrip branch 13 and the second dielectric substrate 6 are located between the second quad-ridged waveguide cavity 2 and the third quad-ridged waveguide cavity 3, and the cross-shaped patch group 11 is located on the lower surface of the third dielectric substrate 7 and the upper surface of the third quad-ridged waveguide cavity 3. The first input port 8 and the second input port 9 are used for planar waveguide coaxial feeding, which excite horizontal polarization and vertical polarization respectively. The third input port 10 is used as the input port of another millimeter wave band antenna.

[0120] This application example has three input ports, namely a first input port 8, a second input port 9, and a third input port 10. The first input port 8 and the second input port 9 excite the Ku-band dual-polarized antenna, and the third input port 10 excites the Ka-band antenna.

[0121] While traditional microstrip dual-polarization antennas offer advantages such as low production cost, compact size, and light weight, they also suffer from high insertion loss. Furthermore, dual-polarization antennas with metal waveguide structures are bulky, costly, and have low bandwidth. Therefore, research is needed to develop high-performance transmission lines that achieve both low loss and broadband characteristics, thereby better meeting the needs of high-capacity and high-speed communications.

[0122] See also Figure 2 The planar waveguide coaxial cable consists of a lower waveguide 21, an upper waveguide 22, an intermediate dielectric substrate 23, and a suspended microstrip line 24. The upper and lower waveguides are filled with air, forming the outer conductor of the coaxial cable. The suspended microstrip line is the inner conductor of the coaxial cable, located at the center of the outer conductor. Similar to traditional coaxial cable performance, it offers broadband and TEM mode propagation.

[0123] In this application example, the impedance of the planar waveguide coaxial line is set to 100 ohms. That is, the outer conductor size W a =1.5 mm, the width of the internal suspended microstrip line W s =0.4 mm.

[0124] Based on this, in a possible application example, the planar waveguide coaxial broadband dual-polarization antenna provided in the application example of this application is composed of a waveguide structure and an easily processed planar microstrip line, with a simple structure and a flexible and simple design method. The planar coaxial waveguide provided in this application example has inherent closedness, so it can achieve a more compact feed network design in the design of large-scale arrays, such as Figure 3This is a schematic diagram of the 2x2 array antenna used in the application example. The dual-polarization antenna feed network utilizes planar coaxial waveguides. The first feed network 31 and the second feed network 32 utilize a series-parallel hybrid one-to-four structure and are positioned perpendicular to each other. To ensure that the antenna elements are excited at the same phase, a meandering delay line (feed delay line 33) is incorporated into the feed network. The meandering line length is one wavelength of the operating frequency band.

[0125] For example, in a possible application example, in order to better achieve impedance matching between the first T-type microstrip line 12 and the quad-ridged waveguide cavity, the height of the first quad-ridged waveguide cavity 1 is one-quarter wavelength of the operating frequency band. Therefore, the height of the first quad-ridged waveguide cavity 1 is set to h1 = 5 mm, the height of the second quad-ridged waveguide cavity 2 is h2 = 1.8 mm, and the height of the third quad-ridged waveguide cavity 3 is h3 = 6.2 mm. The bottom waveguide cavity 10 adopts a square waveguide structure as the signal input of the Ka band. In order to prevent the upper Ku band signal from leaking from the bottom, the size of the bottom waveguide cavity 10 is set to 5.3 mm, thereby achieving high isolation while achieving two frequency bands sharing the quad-ridged waveguide cavity.

[0126] The square waveguide cavity at the bottom of the antenna is expanded to the input port of the Ka-band antenna, so that multiple polarizations can be achieved in a compact structure. In this application, two orthogonal modes (TE 01 Mould and TE 10 In other application examples, different polarizations can be achieved by changing the input mode as required.

[0127] When the first input port 8 and the second input port 9 are excited, the input signal is converted into the TE mode of the quad-ridge waveguide cavity through the TEM mode in the planar coaxial waveguide. 001 Mode and TE 010 The energy coupling from the planar coaxial waveguide to the quad-ridge waveguide cavity is controlled by adjusting the length of the first T-shaped microstrip branch 12 and the second T-shaped microstrip branch 13, thereby achieving horizontally polarized radiation. The length of the first T-shaped microstrip branch is 0.9 mm. The length of the second T-shaped microstrip branch is 3 mm.

[0128] This application example allows for the vertical placement of two T-shaped microstrip branches, resulting in two perpendicular broadband dual-polarization channels. Microstrip lines are easier to process than traditional waveguide coaxial probes, allowing for more flexible design of array antenna feed networks.

[0129] Specifically, the first and second T-shaped microstrip branches 12 and 13 are printed on the lower surfaces of the first and second dielectric substrates 5 and 6. The material used for the first and second dielectric substrates 5 and 6 is Roger RT5880, which has a dielectric constant of 2.2 and a thickness of 0.254 mm. The cross-shaped patch group 11 is located on the lower surface of the third dielectric substrate 7 to suppress grating lobes and improve gain. The material used for the third dielectric substrate 7 is Roger RT5880, which has a dielectric constant of 2.2 and a thickness of 0.508 mm.

[0130] The broadband dual-polarized antenna structure based on planar waveguide coaxial provided in the application example of this application has a compact overall structure size, radiates multiple frequency bands and multiple polarizations on the same aperture surface, and is easy to construct a larger-scale array antenna design.

[0131] In some application examples of the present application, the planar waveguide coaxial broadband dual-polarized antenna can be arranged in a 2*2 array. In other application examples, the value of the planar waveguide coaxial broadband dual-polarized antenna can be changed according to the gain requirement.

[0132] The planar waveguide coaxial broadband dual-polarization antenna structure in this application example was tested. The test data obtained can show that the slot antenna in this application example has good radiation performance, as shown below:

[0133] (1) The antenna realizes horizontal polarization and vertical polarization in the Ku band, and the operating frequency bands are 13.9-16.4 GHz and 14-17.1 GHz. Figure 4 shown.

[0134] (2) In the center frequency band, the isolation between the vertical polarization and the horizontal polarization of the antenna is 15dB. Figure 5 shown.

[0135] (3) The antenna can realize dual-frequency common aperture design, such as Figure 6 As shown, by adding a small-sized waveguide input port at the bottom, a Ka-band antenna is realized with an operating bandwidth of 32.75-34.5 GHz.

[0136] (4) The vertical polarization and horizontal polarization patterns are shown in Figure 7(a) and Figure 7(b), respectively. The cross-polarization isolation is greater than 20 dB, indicating good radiation performance.

[0137] In summary, the planar waveguide coaxial broadband dual-polarization antenna proposed in the application example of this application includes: a quad-ridged waveguide cavity, a planar coaxial waveguide line, a microstrip feeder and a high-frequency waveguide cavity. The planar waveguide coaxial line is used as the feeding structure of the dual-polarization antenna, and the quad-ridged waveguide is used as the main cavity of the antenna. The coaxial structure has the characteristics of broadband. In addition, the use of the quad-ridged waveguide structure not only makes the antenna structure more compact, but also expands the bandwidth of the antenna. Two layers of dielectric substrates carrying microstrip feeders are sandwiched in the middle of the quad-ridged waveguide cavity, where the first microstrip feeder excites horizontal polarization and the second microstrip feeder excites vertical polarization. The high-frequency waveguide cavity at the bottom of the antenna can be expanded to be the input port of another millimeter-wave band antenna, thereby enabling multiple polarizations to be achieved in a compact structure. Through the technical solution in this application, a broadband dual-polarization antenna based on planar waveguide coaxial is provided, which has the advantages of broadband, low loss and miniaturization. This application solves the difficulties in the broadband design of waveguide dual-polarization antennas and their co-aperture applications.

[0138] It should be understood that the present application is not limited to the specific configurations and processes described above and illustrated in the figures. For the sake of brevity, a detailed description of known methods is omitted here. In the above embodiments, several specific steps are described and illustrated as examples. However, the method process of the present application is not limited to the specific steps described and illustrated. Those skilled in the art can make various changes, modifications, and additions, or change the order of the steps after understanding the spirit of the present application.

[0139] In this application, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or replace features of other embodiments.

[0140] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Those skilled in the art will appreciate that various modifications and variations of the present embodiment are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A planar waveguide coaxial broadband dual-polarization antenna, characterized in that: include: A bottom waveguide cavity for exciting high-frequency signals, and a quad-ridged waveguide assembly stacked on the bottom waveguide cavity for exciting low-frequency signals; The quad-ridged waveguide assembly is provided with two mutually perpendicular T-shaped microstrip branches to form mutually perpendicular dual-polarization modes, and the quad-ridged waveguide assembly is further provided with planar waveguide coaxial lines respectively connected to the two T-shaped microstrip branches and perpendicular to each other for respectively performing dual-polarization excitation on the low-frequency band signal; The quad-ridged waveguide assembly comprises: a first quad-ridged waveguide cavity, a first dielectric substrate, a second quad-ridged waveguide cavity, a second dielectric substrate, a third quad-ridged waveguide cavity and a third dielectric substrate stacked in sequence; Between the first quad-ridged waveguide cavity and the first dielectric substrate, and between the second quad-ridged waveguide cavity and the second dielectric substrate, a T-shaped microstrip branch and a planar waveguide coaxial line are provided which are perpendicular and connected to each other; A cross-shaped patch group is provided between the third quad-ridged waveguide cavity and the third dielectric substrate to suppress grating lobes and increase gain; The first quad-ridged waveguide cavity is stacked on the bottom waveguide cavity.

2. The planar waveguide coaxial broadband dual-polarization antenna according to claim 1, characterized in that: A first T-shaped microstrip branch and a first planar waveguide coaxial line are provided on one side of the first quad-ridged waveguide cavity close to the first dielectric substrate, and the first planar waveguide coaxial line serves as a first input port of the planar waveguide coaxial broadband dual-polarization antenna to perform horizontal polarization excitation on Ku-band signals; The height of the first quad-ridged waveguide cavity is initially set to a quarter wavelength of a preset operating frequency; When the first input port is excited, the input signal is converted to the TE mode of the first quad-ridged waveguide cavity through the TEM mode in the first planar waveguide coaxial line. 001 mode, and controlling the energy coupling from the first planar waveguide coaxial line to the first quad-ridged waveguide cavity by adjusting the length of the first T-type microstrip branch to achieve horizontally polarized radiation.

3. The planar waveguide coaxial broadband dual-polarization antenna according to claim 2, characterized in that: A second T-shaped microstrip branch and a second planar waveguide coaxial line are provided on one side of the second quad-ridged waveguide cavity close to the second dielectric substrate, the second T-shaped microstrip branch and the first T-shaped microstrip branch are perpendicular to each other, the first planar waveguide coaxial line and the second planar waveguide coaxial line are perpendicular to each other, and the second planar waveguide coaxial line serves as the second input port of the planar waveguide coaxial broadband dual-polarized antenna to perform vertically polarized excitation on Ku-band signals; The height of the second quadruple-ridged waveguide cavity is initially set to one-eighth of the wavelength of a preset operating frequency; When the second input port is excited, the input signal is converted to the TE mode of the second quad-ridged waveguide cavity through the TEM mode in the second planar waveguide coaxial line. 010 mode, and controlling the energy coupling from the second planar waveguide coaxial line to the second quad-ridged waveguide cavity by adjusting the length of the second T-type microstrip branch to achieve vertically polarized radiation.

4. The planar waveguide coaxial broadband dual-polarization antenna according to claim 1, wherein: The bottom waveguide cavity comprises: a square waveguide cavity; A third input port is provided in the square waveguide cavity; the third input port is used to excite a Ka-band signal and expand into an input port of another millimeter-wave band antenna.

5. The planar waveguide coaxial broadband dual-polarization antenna according to claim 1, wherein: The planar waveguide coaxial line comprises: an upper waveguide, a lower waveguide, a suspended microstrip line and an intermediate dielectric substrate arranged in sequence; A suspended microstrip line is coaxially provided on one side of the intermediate dielectric substrate close to the lower waveguide; The upper waveguide and the lower waveguide are both filled with air to form an outer conductor; the suspended microstrip line forms an inner conductor of the planar waveguide coaxial line at the center of the outer conductor.

6. The planar waveguide coaxial broadband dual-polarization antenna according to claim 1, characterized in that: The cross-shaped patch group comprises: four cross-shaped patches; Each of the cross-shaped patches is printed on a side of the third dielectric substrate close to the third quadruple-ridged waveguide cavity and is located on the radiation aperture surface of the third quadruple-ridged waveguide cavity.

7. A common aperture array antenna, characterized in that: include: A plurality of planar waveguide coaxial broadband dual-polarization antennas according to any one of claims 1 to 6 that are connected and share the same aperture; The first quad-ridged waveguide cavity in each of the planar waveguide coaxial broadband dual-polarization antennas and each T-shaped microstrip branch between the first dielectric substrate are connected based on a preset first feeding network; The second quad-ridged waveguide cavity in each of the planar waveguide coaxial broadband dual-polarization antennas and each T-shaped microstrip branch between the second dielectric substrate are connected based on a preset second feeding network.

8. The common aperture array antenna according to claim 7, characterized in that: The first feeding network and the second feeding network are both hybrid structures combining series and parallel connection; Feed delay lines are provided in both the first feeding network and the second feeding network to ensure that the phases of the units excited in series are consistent.

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