Wide Bandwidth Beam Circularly Polarized Segmented Helical Horn Antenna

Abstract

The present invention provides a wide bandwidth beam circularly polarized segmented helical horn antenna, which includes a rectangular waveguide and a helical horn, the helical horn is connected to the waveguide port of the rectangular waveguide, and the rectangular waveguide and the helical horn are arranged coaxially And the inner cavity transitions smoothly. The spiral horn is spirally stretched in the axial direction at the waveguide mouth of the rectangular waveguide with the central axis of the waveguide as the rotation axis, and at the same time expands into a horn-shaped structure in the axial direction. The spiral inner surface of the spiral horn is not The waveguide port setting of the shielded rectangular waveguide is set, and the helix angle of the spiral horn is set to be greater than 180°. A circularly polarized segmented helical horn antenna with wide bandwidth beams according to the present invention combines the advantages of the helical antenna and the waveguide horn antenna. The rectangular waveguide is helically unfolded into a horn shape at the same time in a gradually changing manner, and the wide bandwidth is achieved. It can radiate a wide beam of circularly polarized electromagnetic waves within a wide bandwidth.

Description

technical field [0001] The invention belongs to the technical field of active millimeter wave imaging, and in particular relates to a circularly polarized segmented helical horn antenna with a wide bandwidth beam. Background technique [0002] In recent years, aviation security has gradually become an important part of national security, and civil aviation security checks urgently need a device that can quickly and comprehensively detect personal belongings. Millimeter waves can penetrate common clothing and are not ionizing, so active millimeter wave imaging technology has received a lot of attention. However, the current active millimeter-wave imaging generally has problems such as low resolution and artifacts. Therefore, it was proposed to use circularly polarized electromagnetic waves with wide bandwidth beams to solve this problem. However, the existing circularly polarized antennas generally have the problems of narrow frequency band and narrow beam, which leads to t...

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Problems solved by technology

[0004] In summary, the existing antenna structure always has a trade-off between bandwidth, beam width and circular polarization axis ratio, and it is difficult to meet the requirements of the wide bandwidth beam circularly polarized antenna required by the millimeter-wave imaging system at the same time

At the same time, at millimeter-wave frequencies, due to the small size of the antenna, most of the feeding methods use waveguide direct feeding, which makes it difficult to apply general helical antennas.

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