Low-sidelobe microwave antenna and design method thereof

Abstract

The invention discloses a microwave antenna with a low side lobe. The microwave antenna comprises a main reflecting surface, a feed source and a surrounding edge, wherein the main reflecting surface is of a rotating paraboloid structure, and a feed source is arranged at the focus of the main reflecting surface; the feed source comprises a radiation source, an auxiliary reflecting surface, a circular waveguide and a dielectric ring arranged on the splashing plate; the surrounding edge is arranged around the edge of the main reflecting surface and is used for absorbing signals exceeding the receiving range of the main reflecting surface; geometric parameters of the dielectric ring are configured to enable a feed source directional diagram to conform to improved generalized Taylor displacement distribution, an expression of the improved generalized Taylor displacement distribution is # imgabs0 #, rb is a center shielding radius, B1 is a constant larger than 0.45, J0 is a value of a first zero point of a zeroth-order Bessel function, and the feed source directional diagram is adjusted by adjusting the geometric parameters of the dielectric ring on the basis of the expression. And the microwave antenna can achieve the effect of low side lobe.

Description

Technical Field

[0001] The present invention relates to the technical field of communication antennas, and in particular, to a microwave antenna with low sidelobes and a design method thereof. Background Art

[0002] With the rapid development of wireless communication technology, the demand for microwave antennas in the fields of mobile communication, satellite communication, radar systems, etc. is increasing day by day. Especially in complex electromagnetic environments and high-density equipment deployment scenarios, higher requirements are put forward for the performance of antennas. Although traditional parabolic antennas and Cassegrain antennas can achieve basic directional radiation functions, their sidelobe levels usually only meet the ETSI CLASS3 standard (sidelobe level is about -30dB to -35dB), and signal crosstalk is likely to occur in multi-device coexistence or strong interference environments, and the cross-polarization suppression ability is limited.

[0003] In the prior art, although the method of optimizing the feed pattern through Taylor distribution can partially improve the sidelobe performance, there are still problems in practical applications such as insufficient fitting degree between the pattern and the theoretical distribution, and it is difficult to effectively suppress the edge diffraction field, resulting in high return loss and unable to achieve the effect of low sidelobes. Summary of the Invention

[0004] An object of the present invention is to solve at least one of the technical problems existing in the prior art. The present invention proposes a microwave antenna with low sidelobes and a design method thereof. By adjusting the geometric parameters of the dielectric ring, the feed pattern is made to conform to the improved generalized Taylor displacement distribution, which can effectively reduce the return loss, thereby achieving the effect of low sidelobes.

[0005] An embodiment of the present invention provides a microwave antenna with low sidelobes. The microwave antenna includes: a main reflector, a feed, and a surrounding edge; wherein, the main reflector is a rotating parabolic surface structure, and the feed is arranged at its focus; the feed includes a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring arranged on a splash plate; the surrounding edge is arranged around the edge of the main reflector for absorbing signals exceeding the receiving range of the main reflector; the geometric parameters of the dielectric ring are configured such that the feed pattern conforms to the improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central blockage radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th order Bessel function.

[0006] In some embodiments, the edge of the dielectric ring forms an inclined surface, and the inclination angle of the inclined surface is configured such that the amplitude change of the feed pattern conforms to the increasing or decreasing trend of the Taylor distribution.

[0007] In some embodiments, in the improved generalized Taylor displacement distribution, rb Set to 0.1 times the radius, B1 is set to 0.5, and the debugging range of the dielectric ring covers an annular area from 0.2 times to 1 times the radius.

[0008] In some embodiments, a first absorbing material is attached to the inner side of the border, and the first absorbing material is used to absorb sidelobe signals beyond 60 degrees; the outer side of the circular waveguide is uniformly coated with a second absorbing material along the circumferential direction.

[0009] In some embodiments, the inclined surface at the edge of the dielectric ring is a multi-step inclined surface, and the multi-step inclined surface is composed of at least two sub-inclined surfaces with different inclination angles. The sub-inclined surfaces at all levels are connected by short transition sections, forming a segmented gradient structure as a whole.

[0010] In some embodiments, the sidelobe level of the microwave antenna is lower than -40 dB.

[0011] In some embodiments, the design method is applied to a low-sidelobe microwave antenna, and the microwave antenna includes a main reflector, a feed source, and a border; wherein, the main reflector is a rotating paraboloid structure, and the feed source is arranged at its focus; the feed source includes a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring arranged on a splash plate; the border is arranged around the edge of the main reflector and is used to absorb signals beyond the receiving range of the main reflector; the geometric parameters of the dielectric ring are configured such that the feed source pattern conforms to an improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central blockage radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th-order Bessel function; the design method includes: calculating the amplitude distribution parameters of the feed source pattern based on the improved generalized Taylor displacement distribution formula; adjusting the geometric shape of the dielectric ring according to the amplitude distribution parameters to make the feed source pattern conform to the Taylor distribution corresponding to the improved generalized Taylor displacement distribution formula.

[0012] In some embodiments, after adjusting the geometric shape of the dielectric ring, the design method further includes: attaching a first absorbing material to the inner side of the border, and uniformly coating a second absorbing material along the circumferential direction on the outer side of the circular waveguide.

[0013] In some embodiments, after adjusting the geometric shape of the dielectric ring, the design method further includes: experimentally verifying whether the sidelobe level and cross polarization of the microwave antenna meet the preset standards; in the case of not meeting the preset standards, adjusting the geometric shape of the dielectric ring again based on preset rules.

[0014] In some embodiments, after experimentally verifying whether the sidelobe level and cross polarization of the microwave antenna meet the preset standards, the design method further includes: in the case of not meeting the preset standards, adjusting the bevel angle of the edge of the dielectric ring according to the results of the experimental verification, so that the dielectric thickness in the signal path changes uniformly, to optimize the fitting degree between the feed pattern and the Taylor distribution.

[0015] According to an embodiment of the present invention, a low-sidelobe microwave antenna and its design method are provided, which at least have the following beneficial effects: The microwave antenna includes a main reflector, a feed, and a surrounding edge. Among them, the main reflector adopts a rotating paraboloid structure, and the feed is arranged at the focus. The feed consists of a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring on the splash plate. The geometric parameters of the dielectric ring are optimized based on the improved generalized Taylor displacement distribution, and its mathematical expression is: Where r b is the central blockage radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th-order Bessel function. By adjusting the geometric shape of the dielectric ring, such as a multi-step bevel design, this distribution can make the feed pattern strictly fit the Taylor distribution in the region from 0.2 times to 1 times the radius, thereby controlling the sidelobe level below -40 dB, and at the same time reducing the return loss to below -20 dB, effectively improving the performance indicators of the antenna.

[0016] Other features and advantages of the present invention will be described in the following specification, and part of them will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures specifically pointed out in the specification, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings are used to provide a further understanding of the technical solutions of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation to the technical solutions of the present invention.

[0018] The present invention will be further described below in conjunction with the drawings and embodiments;

[0019] Figure 1 is a schematic structural diagram of a low-sidelobe microwave antenna provided in an embodiment of the present invention;

[0020] Figure 2 is a schematic structural diagram of a feed provided in an embodiment of the present invention;

[0021] Figure 3 is a flowchart of the steps of a design method for a low-sidelobe and low-cross-polarization microwave antenna provided in an embodiment of the present invention;

[0022] Figure 4 It is a flowchart showing the steps of adjusting the geometry of the dielectric ring provided in an embodiment of the present invention;

[0023] Figure 5 It is the feed pattern provided in an embodiment of the present invention. Detailed Embodiments

[0024] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The role of the drawings is to supplement the description in the text part of the specification, enabling people to intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be construed as a limitation on the protection scope of the present invention.

[0025] In the description of the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more, "greater than", "less than", "exceeding", etc. are understood as not including the number itself, "above", "below", "within", etc. are understood as including the number itself, "any one" means one or more, and "at least one of the following" and its similar expressions refer to any combination of these items, including any combination of single or plural items. If there is a description of "first" and "second", it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0026] It should be noted that the terms such as "set", "installed", "connected", etc. in the embodiments of the present invention should be understood in a broad sense. Those skilled in the art can reasonably determine the specific meanings of the above terms in the embodiments of the present invention in combination with the specific content of the technical solution. For example, the term "connected" can be a mechanical connection, an electrical connection, or a connection that can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium.

[0027] It should be noted that the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] At present, with the rapid development of wireless communication technology, the demand for microwave antennas in the fields of mobile communication, satellite communication, and radar systems is increasing day by day. Especially in complex electromagnetic environments and high-density device deployment scenarios, higher requirements are placed on the performance of antennas. Although traditional parabolic antennas and Cassegrain antennas can achieve basic directional radiation functions, their sidelobe levels generally only meet the ETSI CLASS3 standard (sidelobe levels are approximately -30 dB to -35 dB), which is prone to signal crosstalk in multi-device coexistence or strong interference environments, and the cross-polarization suppression ability is limited. In the existing technology, although the method of optimizing the feed pattern through Taylor distribution can partially improve the sidelobe performance, there are still problems in practical applications such as insufficient fitting degree between the pattern and the theoretical distribution, and difficulty in effectively suppressing the edge diffraction field, resulting in high return loss and inability to achieve the effect of low sidelobes.

[0029] Based on this, the purpose of the present invention is to solve at least one of the technical problems existing in the prior art. The present invention proposes a low-sidelobe microwave antenna and its design method. By adjusting the geometric parameters of the dielectric ring, the feed pattern is made to conform to the improved generalized Taylor displacement distribution, which can effectively reduce the return loss and thus achieve the effect of low sidelobes.

[0030] The present invention will be further described below in conjunction with the drawings and embodiments;

[0031] Reference Figure 1 and Figure 2 , Figure 1 is a schematic structural diagram of a low-sidelobe microwave antenna provided in an embodiment of the present invention; Figure 2 is a schematic structural diagram of a feed provided in an embodiment of the present invention; An embodiment of the present invention provides a low-sidelobe microwave antenna, which includes: a main reflector 100, a feed 200, and a surrounding edge 300; wherein, the main reflector 100 is a rotating parabolic structure, and the feed 200 is arranged at its focus; the feed 200 includes a radiation source, a sub-reflector 210, a circular waveguide 230, and a dielectric ring 220 arranged on a splash plate; the surrounding edge 300 is arranged around the edge of the main reflector 100 for absorbing signals exceeding the reception range of the main reflector 100; the geometric parameters of the dielectric ring 220 are configured such that the feed pattern of the feed 200 conforms to the improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central blocking radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th-order Bessel function.

[0032] In some embodiments, the sub-reflector 210 is located in front of the main reflector 100 and is used to reflect the electromagnetic waves converged by the main reflector 100 a second time, optimize the directivity of the antenna, and further focus or spread the beam of the main reflector 100 to improve the gain or adjust the beam width; the radiation source is used to generate or receive electromagnetic waves; the splash plate is a metal / dielectric structure installed around the radiation source or in the feeding system and is used to control the scattering direction of the electromagnetic waves, suppress the side lobes or adjust the main beam shape.

[0033] Among them, the sub-reflector 210 is fixed in front of the main reflector 100 by a support rod, and their axes are strictly aligned. The position of the sub-reflector 210 is determined according to the focal length and the hyperbolic eccentricity of the main reflector 100. For example, the spacing can be 0.2 to 0.3 times the focal length of the main reflector 100. The radiation source is installed at the center of the feed 200, such as the open end of a horn antenna. The splash plate is part of the feed 200 and is arranged around the radiation source; in addition, the splash plate can be fixed to the front end of the feed 200 through a flange or a snap structure, and the geometric shape of the dielectric ring 220 provided thereon directly affects the radiation pattern of the feed 200, and thus regulates the energy distribution of the main / sub-reflector 210.

[0034] It can be understood that the signal transmission process is as follows: the radiation source generates electromagnetic waves → the splash plate adjusts the wavefront phase / amplitude → the electromagnetic waves are guided by the feed 200 to the sub-reflector 210 → the sub-reflector 210 reflects a second time to the main reflector 100 → the main reflector 100 radiates the beam directionally into space; the signal reception process is as follows: the main reflector 100 receives external electromagnetic waves → focuses on the sub-reflector 210 → the sub-reflector 210 reflects to the feed 200 → the splash plate suppresses stray signals → the radiation source transmits the signal to the back-end circuit. The inclined plane formed by the dielectric ring 220 of the splash plate can make the radiation pattern of the feed 200 conform to the Taylor distribution and reduce the side lobe level.

[0035] It can be understood that the microwave antenna includes a main reflector 100, a feed 200 and a surrounding edge 300. Among them, the main reflector 100 adopts a rotating paraboloid structure, and the feed 200 is set at the focus. The feed 200 is composed of a radiation source, a sub-reflector 210, a circular waveguide 230 and a dielectric ring 220 on the splash plate. The geometric parameters of the dielectric ring 220 are optimized based on the improved generalized Taylor displacement distribution, and its mathematical expression is: Among them, r b is the central occlusion radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th-order Bessel function. By adjusting the geometric shape of the dielectric ring 220, such as a multi-step inclined plane design, this distribution can make the radiation pattern of the feed 200 strictly conform to the Taylor distribution in the region of 0.2 times to 1 times the radius, so as to control the side lobe level below -40 dB and at the same time reduce the return loss below -20 dB, effectively improving the performance indicators of the antenna.

[0036] In some embodiments, it can be understood that in the improved generalized Taylor displacement distribution parameter setting, rb = 0.1R represents that the central occlusion radius is set to 0.1 times the radius, avoiding excessive occlusion of the central area of the main reflector 100, and at the same time reducing the gain loss caused by the occlusion of the feed 200; B1 = 0.5 represents that this constant controls the gradient of the amplitude distribution. Setting it to 0.5 can achieve a smooth transition in the region from 0.2R to 1R, avoiding sharp fluctuations in the pattern; the range from 0.2R to 1R represents the main distribution area of the sidelobe energy. By adjusting the geometric shape of the dielectric ring 220 in this region, such as thickness and bevel angle, the amplitude of the radiation field can be precisely controlled.

[0037] In some embodiments, the edge of the dielectric ring 220 is processed into a bevel, and the inclination angle can be configured according to the amplitude gradient requirement of the Taylor distribution, so that the amplitude of the feed 200 pattern increases or decreases gradually in a specific region according to the Taylor distribution requirement to suppress the sidelobe; it is worth noting that the bevel formed by processing the edge of the dielectric ring 220 can make the dielectric thickness increase or decrease uniformly in the signal paths with different radiation angles, which can reduce the reflected signal and the return loss; and it is not easy to have fluctuations in the feed 200 pattern, making the curve more conform to the generalized Taylor displacement distribution, improving the technical effect of low cross-polarization and low sidelobes.

[0038] In some embodiments, the bevel achieves this goal in the following way: if the Taylor distribution requires a low amplitude in the central region and a high amplitude at the edge, the bevel angle is small, such as 5°, so that the dielectric thickness gradually thins from the center to the outside, guiding the electromagnetic wave energy to concentrate at the edge; if the distribution requires a high amplitude in the center and a low amplitude at the edge, the bevel angle is large, such as 15°, and the dielectric thickness thickens from the center to the outside, suppressing the radiation energy at the edge.

[0039] In some embodiments, a first wave-absorbing material is provided on the inner side of the surrounding edge 300. The first wave-absorbing material can adopt a multi-layer composite structure, for example, an outer layer of conductive carbon fiber, a middle ferrite layer, and an inner layer of flexible foam. Among them, the outer layer of conductive carbon fiber is used to reflect high-frequency clutter, the middle ferrite layer is used to absorb signals from 6 GHz to 40 GHz, and the inner layer of flexible foam is used to buffer vibration; it can be understood that corresponding Figure 1 , by debugging the sub-reflector and forming a bevel at the edge of the dielectric ring, the pattern is the lowest at 165 degrees. Among them, 180 degrees corresponds to the center of the main reflector, 160 degrees corresponds to about 0.2 times the radius, 130 degrees reaches the highest, and then starts to decline at 105 degrees, conforming to the amplitude change of the Taylor distribution. For signals exceeding 60 degrees, they have exceeded the acceptance range of the main reflector. Therefore, the present invention will adopt the method of attaching wave-absorbing materials to the surrounding edge to absorb them, reducing the sidelobe and the cross-polarization at the same time.

[0040] Further, attaching an absorbing material to the outer side of the circular waveguide 230 can prevent diffraction and achieve the technical effects of low sidelobes and low cross-polarization. The second absorbing material on the outer side of the circular waveguide 230 can be a ferrite coating applied in segments along the circumference to suppress the diffraction field generated on the surface of the circular waveguide 230. In addition, the thickness of the absorbing material can be dynamically adjusted according to the intensity of the diffraction field. For example, in strong diffraction regions such as waveguide joints, 1.5 mm to 2 mm is coated, and in weak regions, 0.5 mm to 1 mm is coated.

[0041] In some embodiments, the multi-step inclined plane at the edge of the dielectric ring 220 is composed of at least two levels of sub-inclined planes, and each level is connected by a short transition section. For example, the multi-step inclined plane is divided into three levels: 5°, 10°, 15°, and the length accounts for 10% to 20% of the sub-inclined plane. It can be understood that different steps correspond to wavelengths of different frequency bands. For example, the 5° inclined plane optimizes the low-frequency band (6 GHz to 18 GHz), and the 15° inclined plane optimizes the high-frequency band (18 GHz to 40 GHz).

[0042] In some embodiments, the sidelobe level of the microwave antenna is lower than -40 dB. It can be understood that the sidelobe level lower than -40 dB is a core requirement of ETSI-CLASS4. Through the solution of the present invention, the improved Taylor distribution and the multi-step inclined plane jointly control the amplitude distribution of the radiation field, and the absorbing layer of the perimeter 300 and the circular waveguide 230 directionally absorbs stray signals, enabling the microwave antenna to achieve high-performance indicators of sidelobe level ≤ -40 dB, cross-polarization ≤ -35 dB, and return loss ≤ -20 dB, reaching the ETSI-CLASS4 level.

[0043] Reference Figure 3 , Figure 3 is a flowchart of the design method of a low-sidelobe and low-cross-polarization microwave antenna provided in an embodiment of the present invention. In some embodiments, the design method is applied to a low-sidelobe microwave antenna, which includes a main reflector, a feed source, and a perimeter. Among them, the main reflector is a rotating paraboloid structure, and the feed source is arranged at its focus. The feed source includes a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring arranged on a splash plate. The perimeter is arranged around the edge of the main reflector to absorb signals exceeding the reception range of the main reflector. The geometric parameters of the dielectric ring are configured such that the feed source pattern conforms to the improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central blocking radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th-order Bessel function. The design method includes the following steps:

[0044] Step S310, calculate the amplitude distribution parameters of the feed source pattern based on the improved generalized Taylor displacement distribution formula.

[0045] Step S320: Adjust the geometry of the dielectric ring according to the amplitude distribution parameter to make the feed pattern conform to the Taylor distribution corresponding to the improved generalized Taylor displacement distribution formula.

[0046] Among them, by calculating the amplitude parameter of the feed pattern through the improved generalized Taylor displacement distribution formula, the amplitude gradient of the radiation field can be precisely controlled, thereby suppressing the sidelobe level. Adjust the geometry of the dielectric ring (such as the bevel angle and thickness distribution) to make the pattern strictly fit the Taylor distribution, reduce the pattern fluctuation, ensure that the sidelobe level is stably lower than -40 dB, and the cross-polarization level is lower than -35 dB.

[0047] In some embodiments, an electromagnetic simulation software (such as CST or HFSS) can be used to perform parametric modeling on the formula Input r b as the central blocking radius, B1 is a constant greater than 0.45, generate the target amplitude distribution curve, and adjust the bevel angle and debugging range (0.2R to 1R) of the dielectric ring through optimization algorithms such as genetic algorithms to reduce the error between the simulated pattern and the Taylor distribution.

[0048] In some embodiments, after adjusting the geometry of the dielectric ring, the design method further includes: attaching a first wave-absorbing material to the inner side of the perimeter, and uniformly coating a second wave-absorbing material along the circumferential direction on the outer side of the circular waveguide.

[0049] Reference Figure 4 , Figure 4 is the flow chart of the steps for adjusting the geometry of the dielectric ring provided in an embodiment of the present invention; in some embodiments, after adjusting the geometry of the dielectric ring, the design method further includes the following steps:

[0050] Step S410: Experimentally verify whether the sidelobe level and cross-polarization of the microwave antenna meet the preset standards;

[0051] Step S420: In the case of not meeting the preset standards, readjust the geometry of the dielectric ring based on the preset rules.

[0052] In some embodiments, after experimentally verifying whether the sidelobe level and cross-polarization of the microwave antenna meet the preset standards, the design method further includes: in the case of not meeting the preset standards, adjust the bevel angle of the edge of the dielectric ring according to the experimental verification results to make the medium thickness change uniformly in the signal path to optimize the fitting degree between the feed pattern and the Taylor distribution; among them, through experimental verification and feedback adjustment, it can be ensured that the sidelobe level is stably ≤ -40 dB, and the cross-polarization ≤ -35 dB, meeting the ETSI CLASS4 standard.

[0053] Reference Figure 5 , Figure 5It is the feed pattern provided by an embodiment of the present invention; in some embodiments, Figure 5 shows the feed pattern (absolute value of far-field gain, Phi = 90°) of the microwave antenna in an embodiment of the present invention. As shown in the figure, within the range of Theta angle from 0° to 180°, the main lobe gain reaches a peak of about 10 dB near Theta = 0°, and the main lobe width (half-power beam width) is about 20°, showing excellent directional radiation ability. In the sidelobe region (Theta > 60°), the gain value decreases significantly, and the sidelobe level within the range of 105° to 165° is stably lower than -40 dB (the lowest value reaches -25 dB), which is about 10 dB higher than the traditional design, fully verifying the optimization effect of the dielectric ring based on the improved generalized Taylor displacement distribution; in addition, near Theta = 90° (cross-polarization sensitive region), the gain value is maintained below -35 dB, indicating that the synergistic effect of the edge absorbing material and the circular waveguide coating effectively suppresses cross-polarization interference. The pattern data is measured by a three-dimensional near-field test system, the test distance is 3 times the wavelength, and the scanning angle covers -180° to 180°. The deviation from the simulation result is less than ±2 dB, further proving the reliability of the design method in the present invention and the broadband stability (6 GHz to 40 GHz) of the antenna.

Claims

1. A microwave antenna with low sidelobes, characterized in that, The microwave antenna includes: a main reflector, a feed source, and a surrounding edge; wherein, the main reflector is of a rotating paraboloid structure, and the feed source is arranged at its focal point; the feed source includes a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring arranged on a splash plate; the surrounding edge is arranged around the edge of the main reflector and is used to absorb signals beyond the reception range of the main reflector; the geometric parameters of the dielectric ring are configured such that the feed source pattern conforms to an improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central occlusion radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the Bessel function of the 0th order.

2. The low sidelobe microwave antenna according to claim 1, wherein, The edge of the dielectric ring forms an inclined surface, and the inclination angle of the inclined surface is configured such that the amplitude change of the feed source pattern conforms to the increasing or decreasing trend of the Taylor distribution.

3. The low sidelobe microwave antenna according to claim 1, characterized in that, In the improved generalized Taylor displacement distribution, r b is set to 0.1 times the radius, B1 is set to 0.5, and the debugging range of the dielectric ring covers an annular region from 0.2 times to 1 time the radius.

4. The low sidelobe microwave antenna according to claim 1, characterized in that, A first wave-absorbing material is attached to the inner side of the surrounding edge, and the first wave-absorbing material is used to absorb sidelobe signals beyond 60 degrees; the outer side of the circular waveguide is uniformly coated with a second wave-absorbing material along the circumferential direction.

5. The low sidelobe microwave antenna according to claim 2, characterized in that, The inclined surface at the edge of the dielectric ring is a multi-step inclined surface, and the multi-step inclined surface is composed of at least two sub-inclined surfaces with different inclination angles, and the sub-inclined surfaces at all levels are connected by short transition sections, forming a segmented gradient structure as a whole.

6. The low sidelobe microwave antenna according to any one of claims 1 to 4, characterized in that The sidelobe level of the microwave antenna is lower than -40 dB.

7. A design method for a low sidelobe and low cross-polarization microwave antenna, characterized in that, The described design method is applied to a low sidelobe microwave antenna, which includes a main reflector, a feed source, and a surrounding edge; wherein, the main reflector is of a paraboloid of revolution structure, and the feed source is arranged at its focus; the feed source includes a radiation source, a sub-reflector, a circular waveguide, and a dielectric ring arranged on a splash plate; the surrounding edge is arranged around the edge of the main reflector for absorbing signals beyond the reception range of the main reflector; the geometric parameters of the dielectric ring are configured such that the feed pattern conforms to an improved generalized Taylor displacement distribution, and the expression of the improved generalized Taylor displacement distribution is: where r b is the central obstruction radius, B1 is a constant greater than 0.45, and J0 is the value of the first zero of the 0th order Bessel function; The design method includes: Based on the improved generalized Taylor displacement distribution formula, calculating the amplitude distribution parameters of the feed source pattern; According to the amplitude distribution parameters, adjusting the geometric shape of the dielectric ring so that the feed source pattern conforms to the Taylor distribution corresponding to the improved generalized Taylor displacement distribution formula.

8. The design method of the low sidelobe and low cross-polarization microwave antenna according to claim 7, characterized in that, After adjusting the geometric shape of the dielectric ring, the design method further includes: Attaching a first wave-absorbing material to the inner side of the surrounding edge, with the first wave-absorbing material used to absorb sidelobe signals beyond 60 degrees, and uniformly coating a second wave-absorbing material along the circumferential direction on the outer side of the circular waveguide.

9. The design method of the low sidelobe and low cross-polarization microwave antenna according to claim 7, characterized in that, After adjusting the geometric shape of the dielectric ring, the design method further includes: Experimentally verifying whether the sidelobe level and cross polarization of the microwave antenna meet the preset standards; In the case of not meeting the preset standards, adjusting the geometric shape of the dielectric ring again based on preset rules.

10. The design method according to claim 9, characterized in that, After experimentally verifying whether the sidelobe level and cross polarization of the microwave antenna meet the preset standards, the design method further includes: In the case of not meeting the preset standards, adjusting the inclined surface angle at the edge of the dielectric ring according to the results of the experimental verification to make the medium thickness in the signal path change uniformly, so as to optimize the fitting degree between the feed source pattern and the Taylor distribution.

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