Benoit Michel Schaller1, Arthur William
Magill1,2, Rolf Gruetter,,3
1Laboratory of Functional
& Metabolic Imaging, Ecole Polytechnique Fdrale de Lausanne, Lausanne,
Vaud, Switzerland; 2Department of Radiology, University of
Lausanne, Switzerland; 3Department of Radiology, Universities of
Lausanne & Geneva, Switzerland
Current on the outside of coaxial cables produces unwanted effects such as radiation, sensitivity to external interference and probe sensitivity to cable positioning. This problem becomes significantly worse as frequency increases. Cable traps block current on the outside of the coaxial cable by creating a high impedance for the common mode signal, making the probe insensitive to different cable loading conditions. This study reviews wave propagation in coaxial cable, describes three common cable trap designs (ferrite, tank and bazooka), and presents a simple method for measuring trap effectiveness.
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