A wide-angle ridged horn feed

Abstract

The utility model provides a wide angle adds ridge corrugated horn feed source, including waveguide cavity and choke groove, the outer wall surface of opening end of waveguide cavity is fixed with choke groove, and the depth direction of choke groove is parallel to the axial direction of waveguide cavity, the utility model discloses a wide angle adds ridge corrugated horn feed source, one aspect, makes the directional deflection of electromagnetic wave in the edge area of reflection surface, enhances the edge illumination energy of reflection surface to improve the aperture efficiency of reflection surface, on the other hand, the inclined electric field of guide mouth surface can radiate wider beam and satisfy the illumination demand of big angle of aperture and small focal length ratio.

Description

Technical Field

[0001] This utility model relates to the field of radio astronomy observation technology, and more specifically, to a wide-angle ridged corrugated horn feed. Background Technology

[0002] Radio telescope antennas are generally reflector antennas, with the feed being a crucial component. Its primary function is to convert high-frequency current or confined electromagnetic waves into radiated electromagnetic energy. Corrugated horns are commonly used high-efficiency feeds; the depth of the corrugated grooves in a corrugated horn can be between 0° and 90° from the horn's axis of symmetry.

[0003] In the prior art, the depth direction of the corrugated groove of the corrugated horn is parallel to the axis of symmetry of the horn. The corrugated groove has multiple annular grooves with the same depth and the top surfaces of the annular grooves are flush. This corrugated horn is suitable for reflector antennas with a focal diameter ratio between 0.4 and 0.5. For reflector antennas with a focal diameter ratio less than 0.4, there are technical problems such as insufficient illumination at the edge of the reflector and low aperture efficiency of the reflector. Utility Model Content

[0004] This invention provides a wide-angle corrugated horn feed source to solve the technical problems of insufficient illumination at the edge of the reflector and low aperture efficiency of the reflector in existing corrugated horns with a focal diameter ratio of less than 0.4.

[0005] This utility model provides a wide-angle corrugated horn feed source with ridges, including a waveguide cavity and a choke groove. The choke groove is fixed to the outer wall surface of the open end of the waveguide cavity, and the depth direction of the choke groove is parallel to the axial direction of the waveguide cavity. The choke groove includes multiple annular grooves. Along the radial outward direction of the waveguide cavity, the top surface of the multiple annular grooves is stepped and decreases sequentially.

[0006] Optionally, the depth of the multiple annular grooves decreases sequentially in the radial outward direction of the waveguide cavity;

[0007] And / or, the number of the annular grooves is greater than or equal to 4 layers and less than or equal to 8 layers.

[0008] Optionally, the ratio of the depth of the annular groove to the center wavelength of the design band is between 0.2 and 0.3;

[0009] And / or, the depth of the annular groove is between 60-85 mm;

[0010] And / or, the ratio of the width of the annular groove to the center wavelength of the design band is between 0.1 and 0.3;

[0011] And / or, the width of the annular groove is between 18-21 mm;

[0012] And / or, the distance between the top surfaces of adjacent annular grooves is between 10-20 mm.

[0013] Optionally, the outermost annular groove is a trapezoidal groove, with a large opening at the top and a small opening at the bottom.

[0014] Optionally, the angle between the inclined sidewall of the trapezoidal groove and the axial direction of the waveguide cavity is between 45° and 60°.

[0015] Optionally, the wide-angle ridged corrugated horn feed also includes a probe; the waveguide cavity is provided with four ridges, which are arranged in a cross orthogonal arrangement; among the oppositely arranged ridges, one ridge is provided with a through hole, and the other ridge is provided with a mounting hole, and the probe passes through the through hole and its end is connected to the mounting hole.

[0016] Optionally, the probe includes a first segment and a second segment, wherein the diameter of the first segment is larger than the diameter of the second segment; the first segment of the probe penetrates the through hole and the end of the second segment is connected to the mounting hole.

[0017] Optionally, the waveguide cavity is a split structure with four arc-shaped waveguide plates; the four ridge plates are respectively installed between adjacent arc-shaped waveguide plates.

[0018] Optionally, the sidewall of the arc-shaped waveguide sheet is provided with a connecting portion, and the ridge sheet is installed between adjacent connecting portions by fasteners;

[0019] And / or, the upper end of the arc-shaped waveguide sheet is provided with a flange portion, and the choke groove is fixed to the flange portion.

[0020] Optionally, the contour curve of the ridge slice adopts a sine square curve, an exponential gradient curve, a polynomial curve, or a piecewise linear curve.

[0021] The wide-angle corrugated horn feed source provided by this utility model has at least the following beneficial technical effects:

[0022] The wide-angle corrugated horn feed provided by this invention features multiple annular grooves with stepped, gradually decreasing top surfaces along the radial outward direction of the waveguide cavity. On one hand, this causes the electromagnetic waves to be directionally deflected in the edge region of the reflecting surface, enhancing the edge illumination energy of the reflecting surface. That is, it balances the center illumination energy and edge illumination energy of the reflecting surface, reducing overflow loss and thus improving the aperture efficiency of the reflecting surface. On the other hand, it guides the aperture surface to form an inclined electric field, which can radiate a wider beam to meet the illumination requirements of a large aperture and small focal diameter ratio. Attached Figure Description

[0023] Figure 1 A schematic diagram of the first structure of a wide-angle corrugated horn feed source provided in this embodiment of the present invention;

[0024] Figure 2 for Figure 1 A bottom view of a wide-angle corrugated horn feed source is shown;

[0025] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of the middle AA section;

[0026] Figure 4 A schematic diagram of the second structure of a wide-angle corrugated horn feed source provided in an embodiment of this utility model;

[0027] Figure 5 for Figure 4 A top view of a wide-angle corrugated horn feed source is shown;

[0028] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure of the middle BB section;

[0029] Figure 7 A schematic diagram of the ridge plate in a wide-angle corrugated horn feed provided in this embodiment of the present invention;

[0030] Figure 8 for Figure 7 The diagram shows a front view of the ridge structure in a wide-angle corrugated horn feed.

[0031] Figure 9 for Figure 8 Schematic diagram of the cross-sectional structure of the middle CC section;

[0032] Figure 10 for Figure 9 A magnified schematic diagram of the structure at point D in the middle;

[0033] Figure 11 A schematic diagram of the exploded structure of the waveguide cavity in a wide-angle corrugated horn feed provided for an embodiment of this utility model;

[0034] Figure 12 Simulation results of a wide-angle ridged corrugated horn feed for the far-field pattern beam in the 1.42GHz band, provided for an embodiment of this utility model;

[0035] Figure 13 The diagram shows the reflection loss test results of a wide-angle corrugated horn feed source provided in this embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 10. Waveguide cavity; 110. Arc-shaped waveguide sheet; 111. Connecting part; 112. Flange part; 20. Choke groove; 210. Annular groove; 211. Trapezoidal groove; 30. Probe; 301. First section; 302. Second section; 40. Ridge; 401. Through hole. Detailed Implementation

[0038] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the following description is provided in conjunction with the appendix. Figure 1-13 Specific embodiments of this utility model will be described in detail.

[0039] In this utility model, the terms "connection" and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure.

[0040] In this utility model, the terms "inner", "outer", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0041] This utility model embodiment provides a wide-angle corrugated horn feed source; see attached drawing. Figures 1-6 The wide-angle corrugated horn feed includes a waveguide cavity 10 and a choke groove 20. The choke groove 20 is fixed to the outer wall surface of the open end of the waveguide cavity 10, and the depth direction of the choke groove 20 is parallel to the axial direction of the waveguide cavity 10. The choke groove 20 includes multiple annular grooves 210. Along the radial outward direction of the waveguide cavity 10, the top surface of the multiple annular grooves 210 is stepped and decreases sequentially. That is, the top surface of the annular groove 210 located on the inner side is higher than the top surface of the annular groove 210 located on the outer side.

[0042] Compared with the existing technology of wide-angle corrugated horn feeds with flat top surfaces of multi-layer annular grooves 210, the wide-angle corrugated horn feed provided in this embodiment of the invention has multiple annular grooves 210 with stepped top surfaces that gradually decrease in the radial direction outward of the waveguide cavity 10. On the one hand, this causes the electromagnetic waves to be directionally deflected in the edge region of the reflecting surface, enhancing the edge illumination energy of the reflecting surface. That is, it balances the center illumination energy and edge illumination energy of the reflecting surface, reduces overflow loss, and thus improves the aperture efficiency of the reflecting surface. On the other hand, it guides the aperture to form an inclined electric field, which can radiate a wider beam to meet the illumination requirements of large aperture and small focal diameter ratio.

[0043] In this embodiment of the invention, the depth of the multi-layer annular grooves 210 decreases sequentially along the radial outward direction of the waveguide cavity 10. This arrangement creates a radiation limiting compensation through the depth gradient of the annular grooves 210, reducing energy leakage at the edge of the reflecting surface and allowing more energy to participate in effective radiation, thereby improving the aperture efficiency of the reflecting surface.

[0044] In this embodiment of the invention, the number of annular slots 210 is greater than or equal to 4 layers and less than or equal to 8 layers. Preferably, the number of annular slots 210 is greater than or equal to 4 layers and less than or equal to 6 layers. It should be noted that if the number of annular slots 210 is too small, for example, less than 3 layers, firstly, the purity of the primary mode (such as TE01) is less than 90%, and the interference of higher-order modes (such as TE11) increases significantly; secondly, the axial ratio bandwidth decreases, and there is scattering at the edges, resulting in a decrease in radiation efficiency. Here, the axial ratio bandwidth refers to the operating frequency band width of a circularly polarized antenna in a specific direction or beam range when the axial ratio does not exceed a certain specified value (usually 3dB). If the number of annular slots 210 is too large, such as more than or equal to 9 layers, firstly, it may cause multimode interference, leading to a decrease in port isolation. Port isolation refers to the ratio of the leakage signal power of other ports to the input signal power when a signal is input to a certain port in the antenna (usually expressed in decibels dB). It is used to reflect the electromagnetic coupling strength between ports. The higher the isolation, the smaller the crosstalk between ports and the purer the signal. Secondly, it may cause thermal stress concentration and thermal deformation.

[0045] Therefore, the wide-angle corrugated horn feed provided in this embodiment of the present invention, by limiting the number of annular grooves 210 within a certain range, can, on the one hand, improve the purity of the master mode and the suppression effect of higher-order modes, thereby improving the port isolation; on the other hand, it can improve the axial ratio bandwidth, reduce energy leakage, thereby improving radiation efficiency; in addition, it can improve the uniformity of mechanical stress distribution of the annular grooves 210 and reduce thermal deformation.

[0046] In this embodiment of the invention, the ratio of the depth of the annular groove 210 to the center wavelength of the design band is between 0.2 and 0.3. It should be noted that if the ratio is too small, for example, less than 0.2, it may lead to low polarization conversion efficiency, weak suppression of higher-order modes, and polarization crosstalk. If the ratio is too large, for example, greater than 0.3, it may lead to radiation pattern distortion and mechanical stress concentration in the annular groove 210, causing deformation. This setting limits the ratio of the depth of the annular groove 210 to the center wavelength of the design band to a certain range, balancing polarization conversion efficiency and structural stability. Preferably, the ratio is 0.25. This setting effectively suppresses higher-order modes in the circular waveguide and reduces cross-polarization levels.

[0047] In this embodiment of the invention, the depth of the annular groove 210 is between 60-85 mm.

[0048] In this embodiment of the invention, the ratio of the width of the annular groove 210 to the center wavelength of the design band is between 0.1 and 0.3. It should be noted that if the ratio of the width of the annular groove 210 to the center wavelength of the design band is too small, the narrow groove will have insufficient heat dissipation area, potentially leading to excessive temperature rise during high-frequency operation; insufficient mode conversion may result in deterioration of the axial ratio and narrowing of the impedance bandwidth. If the ratio of the width of the annular groove 210 to the center wavelength of the design band is too large, the wide groove may cause an imbalance in the aperture field distribution. This configuration limits the ratio of the width of the annular groove 210 to the center wavelength of the design band within a certain range, optimizing polarization characteristics and improving the uniformity of the radiation aperture field distribution.

[0049] In this embodiment of the invention, the width of the annular groove 210 is between 18-21 mm.

[0050] In this embodiment of the invention, the distance between the top surfaces of adjacent annular grooves 210 is between 10-20 mm. It should be noted that if the distance between the top surfaces of adjacent annular grooves 210 is too small, it may lead to excessive electromagnetic coupling and high sidelobe levels; if the distance between the top surfaces of adjacent annular grooves 210 is too large, it may lead to an imbalance in the radiation aperture field distribution and a decrease in main lobe gain. This configuration, by limiting the distance between the top surfaces of adjacent annular grooves 210 to a certain range, can control mode switching, enhance impedance matching, and improve circular polarization purity.

[0051] In this embodiment of the invention, all annular grooves 210 can be rectangular grooves, or the inner annular grooves 210 can be rectangular grooves and the outermost annular grooves 210 can be non-rectangular grooves. For example, see the attached diagram. Figure 6 The outermost annular groove 210 can be a trapezoidal groove 211, with a large opening at the top and a small opening at the bottom. This configuration, with the outermost annular groove being a trapezoidal groove 211, further creates an inclined electric field, thus broadening the far-field beam.

[0052] In this embodiment of the invention, the angle between the inclined sidewall of the trapezoidal groove 211 and the axial direction of the waveguide cavity 10 is between 45° and 60°. It should be noted that if the angle is too small, insufficient electric field deflection may result in poor beam broadening; if the angle is too large, the stability of the trapezoidal groove 211 decreases, making it prone to deformation. Preferably, the angle between the inclined sidewall of the trapezoidal groove 211 and the axial direction of the waveguide cavity 10 can be 45°.

[0053] In this embodiment of the utility model, see appendix. Figures 7-10The wide-angle corrugated horn feed also includes a probe 30; the waveguide cavity 10 has four ridges 40 arranged in a cross-shaped orthogonal configuration; of the opposing ridges 40, one ridge 40 has a through hole 401, and the other ridge 40 has a mounting hole. The probe 30 passes through the through hole 401 and its end is connected to the mounting hole. It should be noted that the opposing ridges 40 are mirror-symmetrically arranged. This arrangement facilitates the simultaneous reception of signals from two polarization directions while ensuring bandwidth performance.

[0054] In this embodiment of the utility model, see appendix. Figure 10 The probe 30 includes a first segment 301 and a second segment 302, with the diameter of the first segment 301 being larger than the diameter of the second segment 302. The first segment 301 of the probe 30 penetrates through the through hole 401, and the end of the second segment 302 is connected to the mounting hole. This configuration, where the probe 30 is stepped and the diameter of the first segment 301 is larger than that of the second segment 302, increases the capacitive reactance at the connection between the probe 30 and the ridge plate 40, offsetting some of the inductive reactance. This improves the impedance matching between the probe 30 and the ridge plate 40, facilitating efficient energy transmission. The second segment 302, with its smaller diameter, achieves precise alignment with the mounting hole, reducing interface reflection loss and improving the energy transmission efficiency between the probe 30 and the ridge plate 40. Furthermore, the larger diameter of the first segment 301 enhances the bending strength of the probe 30.

[0055] In this embodiment of the utility model, see appendix. Figure 7 and Figure 11 The waveguide cavity 10 has a split structure with four arc-shaped waveguide plates 110; four ridge plates 40 are respectively installed between adjacent arc-shaped waveguide plates 110. It should be noted that in the prior art, the four ridge plates 40 are connected to the waveguide cavity 10 with conductive adhesive and fixed with screws. This method cannot completely ensure good electrical contact between the plane of the ridge plate 40 and the inner wall of the waveguide, leading to a significant discrepancy between test results and simulation results. The wide-angle ridged corrugated horn feed provided by this invention, by setting the waveguide cavity 10 as a split structure with all connections being planar, can ensure effective electrical connection, thereby effectively ensuring the consistency between simulation and measured results.

[0056] In this embodiment of the utility model, see appendix. Figure 11 The side wall of the arc-shaped waveguide sheet 110 is provided with a connecting part 111, and the ridge sheet 40 is installed between adjacent connecting parts 111 by fasteners. This arrangement realizes the connection between the ridge sheet 40 and the arc-shaped waveguide sheet 110.

[0057] In this embodiment of the utility model, see appendix. Figure 11The upper end of the arc-shaped waveguide 110 is provided with a flange portion 112, and the choke groove 20 is fixed to the flange portion 112. This arrangement realizes the connection between the arc-shaped waveguide 110 and the choke groove 20.

[0058] In this embodiment of the invention, the contour curve of the ridge 40 adopts a sine square curve, an exponential gradient curve, a polynomial curve, or a piecewise linear curve.

[0059] See appendix Figure 12 The figure shows the simulation results of the far-field pattern beam of the wide-angle ridged corrugated horn feed provided in this embodiment of the invention for the 1.42 GHz frequency band. It should be noted that radio astronomy telescopes typically require a beam half-angle edge level greater than 12 dB to achieve a good balance between gain and noise. As shown in the figure, the wide-angle ridged corrugated horn feed provided in this embodiment of the invention meets the design requirements within a half-beam angle range of 60°-75°.

[0060] See appendix Figure 13 The figure shows the test results of the reflection loss of the wide-angle corrugated horn feed provided in this embodiment of the invention. It should be noted that radio telescopes typically require a reflection loss greater than 20dB in the usable frequency band, as shown in the figure. The wide-angle corrugated horn feed provided in this embodiment of the invention meets the design requirements in the 1.13-1.80GHz frequency band.

[0061] In summary, the wide-angle ridged corrugated horn feed provided by this utility model embodiment achieves a wide-angle beam illumination of 60°-75°, and can achieve high aperture efficiency in reflector or offset reflector antennas with small focal diameter ratio and large aperture.

[0062] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A wide-angle corrugated horn feed, characterized in that, The device includes a waveguide cavity (10) and a choke groove (20). The choke groove (20) is fixed to the outer wall surface of the open end of the waveguide cavity (10). The depth direction of the choke groove (20) is parallel to the axial direction of the waveguide cavity (10). The choke groove (20) includes multiple annular grooves (210). Along the radial outward direction of the waveguide cavity (10), the top surface of the multiple annular grooves (210) is stepped and decreases sequentially.

2. The wide-angle corrugated horn feed according to claim 1, characterized in that, Along the radial outward direction of the waveguide cavity (10), the depth of the multiple annular grooves (210) decreases sequentially; And / or, the number of the annular grooves (210) is greater than or equal to 4 layers and less than or equal to 8 layers.

3. The wide-angle corrugated horn feed according to claim 2, characterized in that, The ratio of the depth of the annular groove (210) to the center wavelength of the design band is between 0.2 and 0.3; And / or, the depth of the annular groove (210) is between 60-85 mm; And / or, the ratio of the width of the annular groove (210) to the center wavelength of the design band is between 0.1 and 0.3; And / or, the width of the annular groove (210) is between 18-21 mm; And / or, the distance between the top surfaces of adjacent annular grooves (210) is between 10-20 mm.

4. The wide-angle corrugated horn feed according to claim 1, characterized in that, The outermost annular groove is a rectangular groove; Alternatively, the outermost annular groove (210) may be a trapezoidal groove (211), with a large upper opening and a small lower opening.

5. The wide-angle corrugated horn feed according to claim 4, characterized in that, The angle between the inclined sidewall of the trapezoidal groove (211) and the axial direction of the waveguide cavity (10) is between 45° and 60°.

6. The wide-angle corrugated horn feed according to any one of claims 1-5, characterized in that, The wide-angle ridged corrugated horn feed also includes a probe (30); The waveguide cavity (10) is provided with four ridges (40), which are arranged in a cross orthogonal arrangement. Among the ridges (40) arranged opposite each other, one of the ridges (40) is provided with a through hole (401), and the other ridge (40) is provided with a mounting hole. The probe (30) passes through the through hole (401) and its end is connected to the mounting hole.

7. The wide-angle corrugated horn feed according to claim 6, characterized in that, The probe (30) includes a first segment (301) and a second segment (302), wherein the diameter of the first segment (301) is larger than the diameter of the second segment (302); the first segment (301) of the probe (30) penetrates the through hole (401) and the end of the second segment (302) is connected to the mounting hole.

8. The wide-angle corrugated horn feed according to claim 6, characterized in that, The waveguide cavity (10) is a split structure with four arc-shaped waveguide plates (110); the four ridge plates (40) are respectively installed between adjacent arc-shaped waveguide plates (110).

9. The wide-angle corrugated horn feed according to claim 8, characterized in that, The sidewall of the arc-shaped waveguide sheet (110) is provided with a connecting part (111), and the ridge sheet (40) is installed between adjacent connecting parts (111) by fasteners; And / or, the upper end of the arc-shaped waveguide plate (110) is provided with a flange portion (112), and the choke groove (20) is fixed to the flange portion (112).

10. The wide-angle corrugated horn feed according to claim 6, characterized in that, The contour curve of the spine (40) adopts a sine square curve, an exponential gradient curve, a polynomial curve, or a piecewise linear curve.

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