Table of Contents Author Guidelines Submit a Manuscript
International Journal of Antennas and Propagation
Volume 2017, Article ID 9750257, 9 pages
Research Article

Miniaturized Circularly Polarized Implantable Antenna for ISM-Band Biomedical Devices

School of Electronic and Information Engineering, Soochow University, Suzhou, Jiangsu 215000, China

Correspondence should be addressed to Changrong Liu; nc.ude.adus@uilrc

Received 31 October 2016; Revised 16 February 2017; Accepted 12 March 2017; Published 30 March 2017

Academic Editor: Symeon Nikolaou

Copyright © 2017 Ke Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A compact circularly polarized antenna operating at 915 MHz industrial, scientific, and medical (ISM) band for biomedical implantable applications is presented and experimentally measured. The proposed antenna can be miniaturized to a large extent with the compact size of 15 × 15 × 1.27 mm3 by means of loading patches to a ring-shaped microstrip patch antenna. An impedance bandwidth of 10.6% (865–962 MHz) for reflection coefficient less than −10 dB can be obtained. Meanwhile, the simulated 3 dB axial-ratio (AR) bandwidth reaches 14 MHz. Finally, the optimized design was fabricated and tested, and the measured results agree well with simulated results.