Planar U-shaped antenna for RFID

Abstract

The invention discloses a planar U-shaped antenna for an FRID. The planar U-shaped antenna for the FRID comprises a dielectric substrate (1), a U-shaped antenna arm (2) printed on the upper surface of the dielectric substrate (1), a feed loop (3) and a metal reflecting plate (7) located on the lower surface of the dielectric substrate (1), wherein the U-shaped antenna arm (2) is connected with the feed loop (3), the feed loop (3) is rectangular, a rectangular groove (5) is etched in the center of the upper edge (4) of the feed loop, and a matching branch (6) is arranged at the center of the feed loop (3). According to the planar U-shaped antenna for the FRID, a plurality of input impedances conjugated with the impedance of an RFID chip can be obtained, a feed position is located inside the U-shaped antenna arm, circuit area is saved, and miniaturization of an RFID system can be achieved easily; meanwhile, due to the fact that the metal reflecting plate is adopted, gain is increased, and the antenna is suitable for being installed on a metal surface and can be widely applied to RFID systems on the UHF frequency band.

Description

technical field [0001] The invention relates to an RFID antenna, in particular to a planar U-shaped antenna for RFID. Background technique [0002] Radio frequency identification technology (RFID) is a non-contact automatic identification technology. Its basic principle is to use the transmission characteristics of radio frequency identification signals and space coupling (electromagnetic coupling or electromagnetic propagation) to realize automatic identification of identified objects. RFID can identify high-speed moving objects and can identify multiple tags at the same time. It is quick and easy to operate and is regarded as a breakthrough technology. First, it can identify a single very specific object; second, it uses radio frequency to read data through external materials; third, it can read multiple objects at the same time. In addition, the amount of stored information is also very large. [0003] RFID uses wireless channels as the transmission medium, and complete...

AI Technical Summary

Problems solved by technology

In traditional RFID antenna design, for RFID chips with complex input impedance, it is often necessary to add an additional matching circuit to convert the input impedance of the chip to a standard impedance of 50 ohms, which increases the complexity of antenna design. At the same time, the gain of traditional RFID antennas is usually low , which affects the working distance of RFID

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