Switching circuit for RF coil ring-down time reduction in pulsed EPR spectrometer

In this paper, we present a four diode switching circuit to reduce the RF coil ring-down time in pulsed EPR spectrometers operating at low Larmor frequency (265 MHz). The proposed switch can be integrated within the matching network of the RF coil. We show that the RF coil ring-down time is reduced by 92 percent with an input power of 0 dBm. A fast switching of 4 ns with an insertion loss of 0.06 dB is obtained. An isolation of 54 dB is achieved between the source and the detector.