Small-sized dual-band dual-circular polarization wide beam multi-layer microstrip antenna

Abstract

The invention relates to a small-sized dual-band dual-circular polarization wide beam multi-layer microstrip antenna which is formed by sequentially overlaying an upper layer S wave band right circular polarized antenna and a lower layer L wave band left circular polarized antenna, wherein the a second medium plate is arranged between the upper layer S wave band right circular polarized antenna and the lower layer L wave band left circular polarized antenna; the directions of electric fields of the upper layer S wave band right circular polarized antenna and the lower layer L wave band left circular polarized antenna are opposite; the upper layer S wave band right circular polarized antenna consists of a square patch of a first cutting angle, a first grounding plate, a probe, an adjustmentpatch and a first coaxial feed cable; and the lower layer L wave band left circular polarized antenna consists of the square patch of a second cutting angle, a second grounding plate and a second coaxial feed cable. In the invention, a feed structure of the upper layer S wave band antenna is reversely arranged to be opposite with the direction of the electric field of the lower layer L wave bandantenna, the interference of the upper layer S wave band antenna and the lower layer L wave band antenna is the smallest, and good circular polarized properties can be obtained. The invention can meetthe conditions that plus is more than-3dB when an elevation angle of L wave band is 5 degrees, and the plus is more than 0 dB when the elevation angle of the L wave band is 20 degrees.

Description

technical field [0001] The invention belongs to the technical field of circularly polarized antennas in the field of satellite communications, and relates to an antenna, in particular to a dual-frequency, double-circularly polarized, wide-beam, multi-layer microstrip antenna, which is suitable for a handheld antenna device of a Beidou navigation system. Background technique [0002] On June 1, 2003, the Beidou system independently developed by my country was officially opened, marking that my country already has a completely independent satellite navigation system. As the large-scale application of Beidou navigation and positioning enters a substantive stage, a large number of independent miniaturized and low-cost satellite positioning platforms, such as personal handheld devices, are required. [0003] The antenna device is one of the key components of the Beidou terminal positioning and communication system, which has a very important impact on the performance of the syste...

AI Technical Summary

Problems solved by technology

Due to the particularity of the construction of the Beidou system in my country, strict requirements are put forward for the design of the antenna. Not only must the terminal antenna have a similar hemispherical radiation pattern in the upper half space, but also have a high gain at low elevation angles. Coupled with the miniaturization requirements of handheld devices, antenna design is very difficult

[0004] Most of the dual-frequency dual circularly polarized microstrip antennas currently on the market are formed by superimposing two circularly polarized antennas with the same electric field direction. It is difficult to meet the high gain characteristics of circular polarization at low elevation angles, so that the The circular polarization and out-of-roundness characteristics are very poor, and it is difficult to meet the stringent requirements of the system

For example, the "three-band wide-beam circularly polarized antenna" disclosed in the Chinese patent (application number: 200620078410.9), although the disclosed antenna satisfies the gain characteristics at low elevation angles, the feeding is complicated, and the axial ratio at low elevation angles is not described characteristic

The literature "Design of a Dual-frequency Dual Circular Polarization Stacked Structure Microstrip Antenna" (Acta Microwave Sinica, June 2006, Supplement to Volume 22, p25-p28) also uses two circularly polarized patches with the same electric field direction to be superimposed Therefore, the axial ratio of the antenna at low elevation angles is greater than 10, and the design uses a broadband power division phase shifter, which makes the structure more complicated

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