Research on the random rolling RFID detection tag antenna on metal surface

The application of radio frequency identification (RFID) technology is becoming wider and wider in the field of industrial detection. The performance of RFID tags in multi-metal environments is also required to be higher and higher. This article proposes a high-efficiency RFID tag antenna that can roll arbitrarily on metal surfaces. The designed tag antenna evolves from the inverted F antenna (IFA). The antenna uses four radiating arms in the columnar layout. One set of opposite arms is connected to the coaxial inner conductor through the feed plane, the other opposite two arms are connected with the outer conductor of the coaxial line, and a slotted rectangular auxiliary plane is placed in the four radiating arms. The overall size of the tag antenna is 11.3 mm×11.3 mm×77.5 mm, the frequency range is 897~932 MHz when rolling in various positions on a metal plane, the bandwidth range of |S11|≤-10 dB is 3.5~8 MHz, and the antenna radiation efficiency reaches 70%. The tag antenna has the advantages of rolling freely in a metal plane, miniaturization, and high efficiency. The proposed tag antenna is connected with the temperature sensor chip and can be used for temperature detection in the complex environment of the industrial internet of things. © 2021, Science Press. All right reserved.