H-field probe with active balun for MRI-conditional testing of medical devices

Authors

Ali Attaran, The University of Western Ontario
William B. Handler, The University of Western Ontario
Blaine A. Chronik, The University of Western OntarioFollow

Document Type

Conference Proceeding

Publication Date

1-22-2019

Journal

Midwest Symposium on Circuits and Systems

Volume

2018-August

First Page

45

Last Page

48

URL with Digital Object Identifier

10.1109/MWSCAS.2018.8624070

Abstract

This work presents the design and construction of a H-field probe with active balun for MRI (magnetic resonance imaging) conditional testing of medical devices. The H-field probe was designed using a small loop antenna with 2 mm radius to have high spatial resolution and sensitivity. It was tuned and matched at a center frequency of 128 MHz, which corresponds to 3 T MRI systems or equivalent RF exposure systems. An active balun with a gain 18.28 dB and noise figure of 0.5 dB was employed to boost the detected H-field signal level. The designed H-field probe and active balun have been fabricated on a double-sided printed circuit board (PCB), FR4 thickness of 1.57 mm and a copper thickness of 35 μm, with overall footprint of 22 mm × 11 mm.