Intelligent antenna system of RFID reading machine

Abstract

The invention discloses a RFID reader intelligent antenna system comprising an antenna array composed of a plurality of antenna elements, an adjustable two-way weighting unit, a merging / dividing unit, a single-pole M-throw radio frequency switch, an A / D down conversion unit, a D / A up conversion unit, a circular device and a DSP signal processor having a demodulating / decoding unit, an encoding / modulating unit, a tag detecting unit and a selection control unit. According to the invention, on one hand, the beam transmitted from the elements are merged to enhance the radio frequency energy in the determined direction or inhibit the radiation energy in other directions; on the other hand, the beam can scan in a sector zone by regulating and merging the parameters and controlling the beam direction, thereby the identification range of the reader is expanded.

Description

technical field [0001] The invention relates to an ultra-high frequency / microwave (UHF / MF) radio frequency identification (RFID) technology, in particular to an RFID reader intelligent antenna system. Background technique [0002] RFID technology is a kind of automatic identification technology. The RFID system formed by RFID technology mainly includes two parts: the reader and the tag. The reader sends a wireless signal to the tag, and the tag returns the chip data stored in it to the reader, thereby achieving the purpose of automatic identification. RFID technology can be divided into frequency bands: low frequency (125KHz), high frequency (13.56MHz), ultra-high frequency (900MHz) and microwave (2.45GHz), and can be divided into three types according to the working mode of tags: active, passive and semi-active. way. The active tag has its own power supply, and the receiving signal and the sending signal are powered by its own power supply; the pa...

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Problems solved by technology

The purpose of these two methods is to strengthen the electromagnetic field strength in the target area, but both methods have defects: the first method (increasing the transmission power of the antenna) is limited, and all countries have limited the radiation power of the antenna when formulating RFID standards. There are restrictions, and the transmitting power of the reader antenna cannot be increased indefinitely; the second method (enhancing the directivity of the reader antenna) improves the transmitting power in the beam direction, but the narrow beam angle sacrifices the recognition of the reader. reading range, which often cannot meet the needs of practical applications

The first method can have greater flexibility and antenna array processing gain, but the structure is complicated and the cost is high; the second method is not as flexible as the first method, and the processing gain is not as high as the first method, but its structure is simple and the cost is high. low, easy to implement, and has been widely used

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