A multi-band cylindrical conformal antenna with low specific absorption rate for wireless medical capsule endoscopy

Abstract

—A multi-band cylindrical conformal endoscopy antenna with low specific absorption rate (SAR) is designed for endoscope applications, which covers the Industrial, Scientific and Medical bands (ISM 902–928 MHz, 2.4–2.4835 GHz), Medical Device Radio Communications Service band (MedRadio 401–406 MHz), and Wireless Medical Telemetry Service (WMTS 608–614 MHz). The proposed antenna radiates as a symmetrical meanderline structure with a center loaded parasitic opened-loop element, which is bent into the cylindrical conformal shape and wrapped onto the inner wall of the capsule shell. The parasitic opened-loop element excites low frequency resonance at 403 MHz and reduces the SAR values of the antenna. The measured relative bandwidth (|S11 |