Ultra-wide-band low-profile printed-type circularly polarized spiral antenna

Abstract

The invention provides an ultra-wide-band low-profile printed-type circularly polarized spiral antenna. The ultra-wide-band low-profile printed-type circularly polarized spiral antenna comprises a first dielectric substrate set to be hollow and cylindrical, a spiral metal sheet arranged on the outer surface of the first dielectric substrate in a spirally-wounded mode, a second dielectric substrate arranged at the bottom of the first dielectric substrate and connected with the first dielectric substrate and a metal grounding plate arranged at the bottom of the second dielectric substrate, connected with the second dielectric substrate and used for grounding, wherein the cross section direction of the second dielectric substrate is perpendicular to the axial direction of the first dielectric substrate. Due to the fact that the width of the spiral metal sheet is adjustable, input impedance of the antenna can be controlled by changing the width of the metal sheet, and an ultra-wide-band impedance band width can be realized at the same time; on the basis of the low-profile feature of the antenna is maintained, the polarized radiation feature and the high-gain characteristic of an ultra-wide band are realized, and the polarized band width can be covered by the impedance band width.

Description

technical field [0001] The invention relates to the field of antennas, in particular to an ultra-wideband low-profile printed circularly polarized helical antenna. Background technique [0002] In the traditional antenna family, antennas with circularly polarized radiation characteristics include microstrip patch antennas, multi-feed quadrifilar helical antennas (Quadrifilar Helical Antenna), planar helical antennas (Spiral Antenna) and axial mode helical antennas (Axial -Mode Helical Antenna), etc. [0003] Among them, the circularly polarized microstrip patch antenna with a single feed point has a narrow working bandwidth (generally within 3%). [0004] The four-arm helical antenna needs to design a complex feed network to realize the multi-feed point working mode, the antenna structure is complex, and the antenna gain is small (generally below 4dBi). [0005] The planar helical antenna has the characteristics of wide frequency band and wide beam, but because it has two ...

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Problems solved by technology

[0011] In view of the above deficiencies in the prior art, the purpose of the present invention is to provide an ultra-wideband low-profile printed circularly polarized helical antenna, which solves the problem that the input impedance of the metal wire helical antenna in the prior art is relatively large (greater than 100Ω), and it is difficult to directly Impedance matching with 50Ω excitation source, and the defect that the profile height of the antenna is large

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