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CN-122026111-A - Broadband low sidelobe corrugated horn antenna

CN122026111ACN 122026111 ACN122026111 ACN 122026111ACN-122026111-A

Abstract

The invention discloses a broadband low-sidelobe corrugated horn antenna which comprises a rectangular waveguide, a radiating element and an arc-shaped curled structure, wherein the rectangular waveguide is provided with a strip-shaped cavity, the radiating element is internally provided with a fan-shaped radiating cavity, and the arc-shaped curled structure is formed by two axisymmetrically arranged inwards curled metal curved surfaces. The segmented corrugated grooves are arranged at the edges of the inner cavity of the fan-shaped radiation cavity, so that the electromagnetic field distribution is accurately regulated and controlled, the wide wave beam optimization is realized, meanwhile, the aperture field distribution can be more uniform due to the constraint effect on the surface current, the wave beam shrinkage caused by the abrupt change of the fringe field is avoided, and the wave beam width in a wide frequency band is kept stable. The invention adopts an arc-shaped curled edge structure formed by two axisymmetric inwards curled metal curved surfaces, the metal curved surfaces with tooth grooves of the saw realize wide wave beams through smooth transition of a fringe field, realize gradual transition from waveguide to free space, and obviously reduce reflection loss. The invention realizes the cooperative promotion of beam broadening, sidelobe suppression and gain stabilization through the cooperative action of the fan-shaped radiation cavity and the metal curved surface with the tooth slot.

Inventors

  • ZHOU TAO
  • ZHANG SHAOJIE
  • Qi Xuanyue
  • ZHANG YUE
  • Sheng Haokang
  • Ge Zhouchi

Assignees

  • 杭州电子科技大学

Dates

Publication Date
20260512
Application Date
20260129

Claims (10)

  1. 1. A wideband low sidelobe corrugated horn antenna, comprising: a rectangular waveguide (1) with a strip-shaped cavity (5) inside; The radiation element is internally provided with a fan-shaped radiation cavity (2), and one end of the fan-shaped radiation cavity (2) is communicated with the strip-shaped cavity (5); The arc-shaped curled edge structure (3) is composed of two metal curved surfaces which are axially symmetrically arranged and curled inwards, a horn-shaped caliber is formed between the two metal curved surfaces, and the other end of the fan-shaped radiation cavity (2) is communicated with the smaller end of the horn-shaped caliber.
  2. 2. A broadband low sidelobe corrugated horn antenna according to claim 1, wherein the inner walls of both sides of said fan-shaped radiating cavity (2) are provided with periodically arranged corrugated grooves (4).
  3. 3. A broadband low sidelobe corrugated horn antenna according to claim 2, wherein said corrugated slots (4) are rectangular slots and are arranged in a segmented array along the propagation direction of electromagnetic waves; The rectangular groove close to the rectangular waveguide (1) is used as a low-frequency-band corrugated groove, has larger size and larger interval, and is used for equivalently introducing capacitive load in a low frequency band so as to improve the matching degree; The rectangular grooves far away from the rectangular waveguide (1) are used as high-frequency-band corrugated grooves, have smaller size and finer spacing, and are used for equivalently introducing inductive load in a high frequency band to inhibit standing waves.
  4. 4. A broadband low sidelobe corrugated horn antenna according to claim 3, wherein each side of the inner wall corrugated groove (4) of the fan-shaped radiation cavity (2) comprises at least 7 sets of groove bodies, the lengths of which decrease periodically in the propagation direction of the electromagnetic wave by 0.1mm to 0.9mm each time.
  5. 5. A wideband low sidelobe corrugated horn antenna according to claim 1, wherein the end edges of said arc-shaped curled structures (3) are provided with periodically arranged saw tooth grooves.
  6. 6. The wideband low sidelobe corrugated horn antenna of claim 5, wherein said saw tooth grooves are triangular grooves.
  7. 7. A wideband low sidelobe corrugated horn antenna according to any of claims 1 to 6, wherein: the long side of the rectangular waveguide (1) is 108mm to 110mm, the short side is 83mm to 85mm, and the thickness is 24mm to 26mm; the side length of the fan-shaped radiation cavity (2) is 270mm to 272mm; the included angle between the fan-shaped radiation cavity (2) and the rectangular waveguide (1) is 112-114 degrees; the included angle between the fan-shaped radiation cavity (2) and the arc-shaped curled edge structure (3) is 157-159 degrees.
  8. 8. A wideband low sidelobe corrugated horn antenna of claim 7, wherein: The overall thickness of the radiating unit is 112mm to 116mm, and the thickness of the fan-shaped radiating cavity (2) is 29mm to 31mm.
  9. 9. A wideband low sidelobe corrugated horn antenna as claimed in claim 5 or 6, wherein: the curvature radius of the metal curved surface is 155mm to 165mm, the thickness is 26mm to 28mm, and the arc-shaped part of the metal curved surface is three-quarter circle; The height of the sawtooth grooves is 15.5mm to 15.8mm, and the spacing between adjacent sawtooth grooves is 31mm to 32mm.
  10. 10. A wideband low sidelobe corrugated horn antenna as claimed in claim 3 or 4, wherein: the length of the low-frequency band corrugated groove is 2.8mm to 3.0mm, and the gap is 14mm to 15mm; the length of the high-frequency band corrugated groove is 1.5mm to 1.8mm, and the gap is 14.5mm to 15mm.

Description

Broadband low sidelobe corrugated horn antenna Technical Field The invention relates to the technical field of microwave antennas, in particular to a horn antenna suitable for directional wide beams and low lobes, which can be widely applied to wireless communication systems and radar detection equipment test scenes, and is particularly suitable for military and civil dual-purpose scenes with core requirements on broadband coverage, low side lobes and high gain stability. Background The wide-beam low-sidelobe horn antenna is a core device with microwave and millimeter wave frequency bands having wide coverage and anti-interference accurate radiation, achieves wide coverage characteristics of beam width through innovative schemes such as corrugated groove loading, double-ridge structure optimization, aperture field balance design and the like, suppresses sidelobe level below-25 dB, breaks a technical pain point that the coverage and interference control of the traditional horn antenna are difficult to be compatible, and occupies an irreplaceable position in the fields of military and civil high-frequency communication, detection and measurement. In the application scene level, the antenna needs to penetrate through the multi-core field, namely a feed source component of a reflecting surface antenna in satellite communication and deep space exploration, a wide beam of the feed source component can be compatible with signal offset caused by satellite attitude fluctuation, low sidelobe characteristics reduce universe background noise and ground clutter interference, the feed source component is composed of a core of a satellite-borne communication system and a radio telescope, the radar and electronic countermeasure field, the wide beam supports wide-area scanning of a low-altitude slow-speed target, the low sidelobe design reduces the probability of being captured by enemy reconnaissance, a double-ridge wide beam low sidelobe antenna becomes a key device of electronic interference signal radiation due to wide frequency band and high power tolerance, the wide beam coverage of the feed source component can compensate a short plate with large millimeter wave path loss in 5G millimeter wave communication, the low sidelobe characteristics reduce inter-cell crosstalk, and is suitable for the wide-area coverage requirement of a micro base station, and the electromagnetic compatibility test field is used as a standard radiation source, and is used for electronic equipment radiation interference detection and antenna gain calibration by virtue of stable wide beam and low sidelobe performance. In order to break through the bottleneck, the invention adopts a ripple slot loading technology. By designing periodic or gradual wave on the inner wall, the surface current distribution can be reconstructed, the fringe field distortion is restrained, and the side lobe level is reduced by 5-10 dB, so that the effect of pattern symmetry is realized. Meanwhile, the invention adopts the horn mouth arc hemming design to improve impedance matching and gain. The traditional straight-edge horn mouth has the advantages that the energy of about 10% -30% can be reflected loss due to the abrupt change of the impedance of the medium and the free space, and the arc-shaped curled edges with the saw tooth grooves can slow down the gradient of the impedance change through a smoothly transitional curved surface structure, so that the reflection loss is reduced to below 2% -5%. By combining the sidelobe suppression capability of the corrugated groove with the broadband matching advantage of the arc-shaped curled edge, the characteristics of low sidelobes, wide beams and symmetrical directional patterns of the horn antenna at 7.5-17.4GHz are realized, and the development of the horn antenna in the high-performance, miniaturized and engineering directions is promoted. Disclosure of Invention The invention aims to solve the technical problem of providing a broadband low-sidelobe corrugated horn antenna so as to solve the technical problem that the beam width and the sidelobe level of the traditional horn antenna are difficult to be compatible in a broadband, and realize the unification of the wide beam coverage and the low sidelobe radiation. In order to solve the technical problem, the invention provides a broadband low sidelobe corrugated horn antenna, which comprises the following components: a rectangular waveguide, the inside of which is provided with a strip-shaped cavity; the radiation element is internally provided with a fan-shaped radiation cavity, and one end of the fan-shaped radiation cavity is communicated with the strip-shaped cavity; the arc-shaped curled edge structure is composed of two metal curved surfaces which are axially symmetrically arranged and curled inwards, a horn-shaped caliber is formed between the two metal curved surfaces, and the other end of the fan-shaped radiation cavity is communicated with the smaller end of the