Circularly-polarized wideband antenna

Abstract

The invention relates to a circularly-polarized wideband antenna which comprises an insulating medium plate, a feeding network positioned on the front of the insulating medium plate, a metal bottom plate positioned on the back of the insulating medium plate, and four metal radiation oscillators mounted on the front of the insulating medium plate and connected with the feeding network. The feeding network is used for converting a signal input from an input end into four equal-amplitude signals of which the phase difference is 90 degrees and outputting the four signals to the four metal radiation oscillators from four output ends. The metal bottom plate is a copper-clad plate and is connected to the ground. The metal radiation oscillators are PIFA oscillators. Compared with the prior art, the circularly-polarized wideband antenna provided by the invention has the advantages of wide axial ratio bandwidth, circular polarization, high gain, smallness, stable performance, easy production and the like. The defects of a single-port feeding antenna such as narrow bandwidth and large size are overcome, a complex multi-port feeding system is simplified, the performance is improved, and the circularly-polarized wideband antenna is more suitable to be used in the RFID industry.

Description

technical field [0001] The invention relates to the field of RFID application technology, in particular to a circularly polarized broadband antenna. Background technique [0002] Radio frequency identification is a non-contact automatic identification technology. In the RFID (Radio Frequency Identification, radio frequency identification) system, identification information is stored in an electronic data carrier, and the electronic data carrier becomes a transponder. The identification information stored in the transponder is read by the reader. In some applications, the reader can not only read the stored information, but also write data to the transponder. This read and write operation is through wireless communication between the two parties. to achieve. Microstrip antenna, as a commonly used directional antenna form in RFID system, is of great significance to the development and application of RFID. [0003] Since the concept of microstrip antenna was put forward, it ...

AI Technical Summary

Problems solved by technology

Among them, the structure of the single-point feed circularly polarized microstrip antenna is the simplest, but the disadvantage is that the axial ratio bandwidth is narrow and the practicability is not strong; The layer structure destroys the low profile of the antenna; the four-point feed antenna has a low utilization rate due to its complexity and instability

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