Shielded Current Sensors for Monitoring Parallel Transmission

Karl Edler¹, Marie-France Hang¹, Alexis Amadon¹, Nicolas Boulant¹, Martijn A. Cloos¹, Christopher J. Wiggins¹

Toroidal sensors were attached to the conductors of two decoupled transmit loops and were used to monitor the current during an RF-pulse. These non-resonant sensors were approximately matched to 50 &[Omega] and were also shielded to minimize their coupling to other sources. During the transmit pulse the preamplifiers were replaced with attenuators so that the received signal would remain within the dynamic range of the receiver channels. The results were also compared with the forward power as measured by connecting the directional couplers on the rear of the RF power amplifiers to spare receiver channels.