Low-profile compact linearly polarized and circularly polarized filtering antennas with high selectivity

Abstract

The invention relates to a low-profile compact linearly polarized and circularly polarized filtering antennas with high selectivity and belongs to the technical field of antennas. Each of the two antennas comprises a radiation patch, a feeder line part, a coaxial cable, two dielectric substrates and a grounding plate. The two dielectric substrates are stacked, the radiation patch is arranged on anupper surface of the upper dielectric substrate, the feeder line part is arranged on an upper surface of a lower dielectric substrate, and the grounding plate is arranged on a lower surface of the lower dielectric substrate. The two filtering antennas are uniquely different from a feeder line part, the linearly polarized filtering antenna adopts an inverted-h-shaped feeder line and can interact with the radiation patch to generate two zero points to realize excellent filtering performance, and the circularly polarized filtering antenna adopts a T-shaped feeder line additionally while reserving the linearly polarized feeder line, so that the circularly polarized filtering performance is generated. The linearly polarized and circularly polarized antennas provided by the invention have the advantages of simple structure, good frequency selection and out-of-band rejection characteristics.

Description

technical field [0001] The invention belongs to the technical field of antennas, and relates to a low profile, compact linear polarization and circular polarization filter antenna with high selectivity. Background technique [0002] With the rapid development of wireless communication, the research of various wireless communication devices is constantly evolving towards the direction of compactness, low profile and integration. As a new antenna design method that takes into account both the functions of the filter and the antenna, filter antenna design has entered people's field of vision, and has begun to receive widespread attention. The joint design of antenna and filter is advocated, so that the filter antenna has radiation, impedance matching, Adjacent channel anti-interference, filtering and balance conversion functions. The filter antenna has excellent frequency selection characteristics and good out-of-band suppression ability in frequency and gain response, which i...

AI Technical Summary

Problems solved by technology

The first method is to use the filter directly as the feed network of the antenna to achieve filtering performance. This method can reduce the interconnection loss of the traditional method and reduce the weight of the RF front-end, but this method directly increases the filter antenna to a large extent. size and design complexity

The second method is to use the antenna as the last resonator and impedance load of the filter, so that the antenna has both filtering and radiation functions, but this usually requires coupling and cascading multiple resonators, resulting in a large lateral size

The third method optimizes the antenna, such as etching grooves on the radiator, and adopts a defective ground structure, so that the antenna can exhibit filtering performance without a separate filter structure, but this usually increases its gain ratio Lower when no filter performance is loaded

However, this usually requires the use of multi-layer structures or the introduction of air layers, which will lead to complex structures, high profiles, high costs and difficult processing

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