Eight-arm spiral double-frequency circularly polarized antenna

Abstract

The invention relates to the field of antennas, and discloses an eight-arm spiral double-frequency circularly polarized antenna. The eight-arm spiral double-frequency circularly polarized antenna comprises four low-frequency antenna arms and four high-frequency antenna arms which are mutually independent, and a feed network on a PCB (Printed Circuit Board); the feed network realizes a one-to-four feed network through three bridges and microstrip lines, and four paths of feed output meet the requirements that the amplitude is equal, and the phase is anticlockwise and sequentially lagged by 90 degrees; the tail end of each feed microstrip line comprises a low-frequency feed point, a high-frequency feed point and a short-circuit branch; the four low-frequency antenna arms are respectively connected with the four low-frequency feeding points, and the four high-frequency antenna arms are respectively connected with the four high-frequency feeding points. Through the two groups of independent four-arm spiral antennas and only one feed network, the PCB not only provides a feed function, but also serves as the ground of the antenna, so that the antenna gain is improved while the excellent dual-frequency circular polarization performance is obtained, and meanwhile, the implementation cost is lower.

Description

technical field [0001] The present application relates to the field of antennas, in particular to an eight-arm helical dual-frequency circularly polarized antenna. Background technique [0002] The dual-frequency RTK positioning of the terminal requires a dual-frequency GNSS antenna suitable for the terminal, and generally has the following requirements: 1) Omnidirectionality, to ensure coverage and reception of satellite signals; 2) Low axial ratio, increase RHCP gain, and reduce multipath suppression; 3) Stable phase center meets the centimeter / millimeter level accuracy requirements of dual-frequency RTK positioning; 4) Low cost, suitable for mass promotion of terminal products; 5) Structural form is suitable for terminal product integration. [0003] The dual-frequency GNSS antennas in the current terminal products are generally based on laminated ceramic / dielectric sheets. This type of antenna generally achieves circular polarization through single-feed points / double-fee...

AI Technical Summary

Problems solved by technology

[0003] The dual-frequency GNSS antennas in the current terminal products are generally based on laminated ceramic / dielectric sheets. This type of antenna generally achieves circular polarization through single-feed points / double-feed points. Feed technology, the circular polarization bandwidth is relatively narrow, and making it into a four-feed point requires two independent feed networks, which will increase complexity and cost, and there is no cost advantage

Also, ceramic or dielectric antennas have certain production and debugging costs

In addition, ordinary quadrifilar helical antennas generally can only achieve a single frequency circular polarization

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