Ultrahigh-frequency RFID flexible anti-metal tag antenna based on PIFA structure

The invention discloses an ultrahigh-frequency RFID flexible anti-metal tag antenna based on a PIFA structure, and the antenna comprises a first metal layer, a second metal layer, a third metal layer, a first dielectric layer, a second dielectric layer, a third dielectric layer, a connection part, a first adhesive layer, and a second adhesive layer. The first metal layer comprises a radio frequency chip, a first radiation unit, a second radiation unit and three rectangular metal supporting blocks, each of the first radiation unit and the second radiation unit comprises seven rectangular metal blocks, the second metal layer comprises an eighth rectangular metal block, and the third metal layer comprises three rectangular metal short-circuit blocks and six metal connecting blocks; the PIFA antenna has the advantages that the profile is low, miniaturization can be realized, current is concentrated, gain is high, reading distance is long, simulation verifies that the PIFA antenna has 2.1 dB gain in a metal enviro