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A miniaturized circularly polarized implantable RFID antenna for biomedical applications
Author(s) -
Zhang Yudi,
Liu Changrong,
Liu Xueguan,
Zhang Ke
Publication year - 2020
Publication title -
international journal of rf and microwave computer‐aided engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.335
H-Index - 39
eISSN - 1099-047X
pISSN - 1096-4290
DOI - 10.1002/mmce.22105
Subject(s) - stub (electronics) , bandwidth (computing) , antenna tuner , specific absorption rate , axial ratio , optics , impedance matching , physics , electrical impedance , circular polarization , antenna (radio) , acoustics , electrical engineering , computer science , antenna factor , antenna measurement , telecommunications , engineering , microstrip
A miniaturized circularly polarized implantable antenna operating at ultrahigh frequency band (902‐928 MHz) for radio frequency identification biomedical monitoring is first presented and experimentally validated in this article. The proposed antenna features a compact volume with a dimension of π × (6) 2 × 1.27 mm 3 by employing an extended ring with meandered lines for size reduction. Moreover, adjusting the length of symmetrical meandered lines can introduce two orthogonal modes, which makes for good performance of circular polarization. Superb impedance matching between the chip and tag antenna is well implemented by applying a modified T‐match stub. In the simulation, the antenna achieves a −10‐dB impedance bandwidth of 42 MHz (902‐944 MHz) and 3‐dB axial‐ratio bandwidth is 53 MHz (892‐945 MHz). Finally, the specific absorption rate is also calculated for human safety and the measured reading range reaches the maximum distance of about 87 cm.