A Broadband Circularly Polarized Log-Periodic Antenna

Abstract

The invention belongs to the technical field of wireless communication and discloses a broadband circular polarization log periodic antenna which is provided with a main oscillator, an auxiliary oscillator and a group of parallel double lines, wherein the main oscillator and the auxiliary oscillator are arranged in an orthogonal mode; the main oscillator comprises a plurality of symmetric oscillators that are fed by the parallel double lines in a cross manner to form a log periodic antenna; the auxiliary oscillator comprises a plurality of symmetric oscillators that are connected with the fivesymmetric oscillators of the main oscillator to form five-layers of cross-shaped oscillator antennas; and the value range of the length ratio K of the main oscillator and the auxiliary oscillator inthe cross-shaped oscillator antenna is 1.1-1.5, and the lengths of the auxiliary oscillator in every two adjacent layers of the cross-shaped oscillator antennas are the length of the main oscillator multiplied by K and 1 / K, according to the self-phase-shifting principle of the cross-shaped oscillator antennas, and under the different conditions that the length of the auxiliary oscillator of the first layer of cross-shaped oscillator antenna is the length of the main oscillator multiplied by the ratio K or 1 / K, the circular polarization characteristics of the antenna in two different rotationaldirections can be respectively realized. Compared with a traditional broadband circular polarization log periodic antenna, the broadband circular polarization log periodic antenna is simpler in structure and has the advantages of wide frequency band and circular polarization.

Description

technical field [0001] The invention belongs to the technical field of wireless communication, and in particular relates to a broadband circularly polarized logarithmic period antenna. Background technique [0002] In many communication systems, terminal antennas are required to meet the characteristics of broadband and circular polarization. As a non-frequency-variable antenna, the log-periodic antenna changes periodically with the logarithm of the frequency, and it is easy to realize broadband. The traditional cross-structure circularly polarized log-periodic antenna was first proposed by Ryoji Wakabayashi. It needs to use two sets of collection lines. On the basis of the original log-period antenna, the vibrator on the newly added collection line and the original log-period antenna oscillator They are arranged 90° apart to form two kinds of linear polarization. The two linear polarizations are then passed through a broadband circular polarization bridge to realize circu...

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Problems solved by technology

[0003] In summary, the existing problems in the prior art are: the traditional broadband circularly polarized logarithmic periodic antenna needs two or more feed points, two sets of collection lines and complex phase shifting circuits, making the feed structure very complicated , increasing the complexity and manufacturing cost of the antenna

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