A Low-Noise Differential JFET Amplifier for Magnetic Particle Imaging

In MPIsystemsdesigned for large areas of the human body, drive fields are a significant source of interference for the receive electronics. Their influence, in addition to the direct feedthrough of the signal, can manifest itself in the form of common-modenoise,whichcanbeeffectively suppressed using filters and low-noise amplifiers with a differential architectures. In this work, we demonstrate a prototype of low-noise amplifier based on differential first stage, which works in combination with four order notch receive filter. Our preliminary results show a gain of at least 40 dB over the frequency range of 50-700 kHz, effectively covering measurable harmonic signals for head sized MPIscanner.