RFID High-gain circular polarization fixed RFID antenna

摘要

The present invention is a fixed circularly polarized RFID antenna having broadband and high gain characteristics, and includes a probe feeding part 6 receiving RF power flowing from an external transmission device, and RF power corresponding to a resonance point on a second substrate. ) Is delivered to the square patch 2 via the air layer 7. At this time, it constitutes a square flat patch antenna that operates in the 900MHz band, has a circular polarization and directivity characteristics, and the gain of the antenna must be increased, so it is an antenna structure using a reflector. The two opposite edges of the square patch 2 are cut at the upper layer of the first substrate 1, and the air layer 7 is formed by using the support 4 for the first substrate 1 and the second substrate (reflective plate) 5. It is a wide-band and high-gain antenna formed of a probe feeder (6) by forming a gap between the inner side and the inner half of the reflector plate (5) and the upper side square patch (2) of the first substrate. In addition, the antenna having a circular slot in the center of the square patch (2) upper layer of the first substrate (1) in the same structure as described above has a broadband and high gain characteristics. In addition, instead of the circular slot 8 in the structure, four rectangular slits 10, 11, 12, and 13 are extended to the center of the square patch at the corner edges of the square patch. After the configuration, since the dielectric layer 9 having different dielectric constants is formed on the upper portion of the first substrate 1, it is a multi-band and high gain antenna. ; Antennas, slits and slots, parallel 2-wire feeds