UHF smart shelf rfid reader antenna

Abstract

The invention discloses an antenna for an ultra-high frequency band intelligent shelf RFTD reader. The upper PCB substrate and the lower PCB substrate are supported by nylon columns; There are multiple lower surface metal conduction strips, and the upper surface is copper-clad as a whole; the coaxial street, the upper surface metal conduction strip, the lower surface metal conduction strip and the matching load are connected in series through conductive columns, and the width of the upper surface metal conduction strip is according to the signal transmission The order gradually increases, and the sum of the phase shifts generated by the adjacent single upper surface metal conduction band and the single lower surface metal conduction band is an integer multiple of the wavelength. The invention has strong current, can conveniently design antennas with different areas, and the magnetic field on the upper part of the antenna is evenly distributed.

Description

technical field [0001] The invention belongs to the technical field of antenna structure design and relates to an RFID reader-writer antenna. Background technique [0002] RFID (Radio Frequency Identification, radio frequency identification) technology is a non-contact automatic identification technology. Reader antennas play a key role in RFID systems. The operating frequency of the reader antenna may be low frequency (below 135kHz), high frequency (13.56MHz), ultra-high frequency (860-960MHz) and microwave frequency band (above 2.4GHz). Reader antennas are divided according to the operating distance, which can be divided into near-field antennas and far-field antennas. Near-field reader antennas operating at UHF are ideal for working in tight spaces. Because the near-field antenna only has a strong electromagnetic field at a short distance, and the strength of the electromagnetic field weakens sharply at a slightly further distance, the far-field gain of this antenna is...

AI Technical Summary

Problems solved by technology

These antennas are still not large enough to generate a large uniformly distributed EMF over a large area

The document "RFID Smart Shelf with Confined Detection Volume at UHF, Carla R. Mederios, Jorge R. Costa, and Carlos A. Fernandes, IEEE Antennas and Wireless Propagation Letters, 2008, Vol.7, p773-776" discloses a The shelf antenna realized by the microstrip line, the length of the antenna can be changed freely, but the width cannot be widened

Document "Near-Field Antenna for RFID Smart Shelf in UHF, Wonkyu Choi, Jeong-Seok Kim, Ji-Hoon Bae, Gilyoung Choi, and Jong-Suk Chae, Antennas and Propagation Society International Syposiuim, 2009, p1-4" published Another kind of shelf antenna uses a power divider to divide the feeder into many parallel microstrip lines, and then couples the electric field energy out through many gaps on the floor. This method is due to the active power divider, so the power on each line The current will be reduced, thus reducing the range of the antenna

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