Highly symmetric filter for a fully differential receive chain

Abstract

Differential signaling can provide a higher fidelity of the receive signals in MPI, which is especially important for mobile scanner setups not being operated in a shielding room. A passive, highly symmetrical filter is presented as a part of the fully differential receive chain of the scanner setup. Due to the combined use with a gradiometric receive coil, the requirements for the components in terms of voltage  and current specifications can be lowered which allows for partly building the filter on a PCB with well-matched SMD capacitors and trace lengths. The achieved attenuation for the differential-mode excitation field feedthrough is 77 dB while providing a common-mode rejection of more than 49 dB throughout the receive bandwidth.

Int. J. Mag. Part. Imag. 6(2), Suppl. 1, 2020, Article ID: 2009031, DOI: 10.18416/IJMPI.2020.2009031