Implementation of Miniaturized 433MHz Antenna Using IFA Structure

In this paper, the antenna of a small active RFID for 433MHz is proposed, and the proposed antenna is a kind of built-in antenna, which uses IFA structure. The performance was improved by the change of the spacing between the feed point and short strip, inserting the meander line structure in a radiator, and varying the gap between the radiator and the ground plane in the proposed antenna. To confirm the characteristics of the antenna parameters, HFSS from ANSYS Inc. was used for the analysis. The frequency band of 433MHz Active RFID is from 433.67 to 434.17 MHz. There is a value of return loss less than ?9.54 dB in 433MHz band of the active RFID, and the maximum antenna gain is -4.28dBi. The Jig size of the proposed antenna is 72 × 44 × 1mm, and the size of the antenna area is 35.5 × 19.5mm. The result proved the possibility of the practical use on miniaturized 433MHz antenna using IFA structure that came from comparing and analyzing the measured and simulated data of the antenna.