A FET analogue switch for pulsed NMR receivers

P K Grannell, M. J. Orchard, Peter Mansfield, A. N. Garroway, D. C. Stalker

Journal of Physics E Scientific Instruments · 1973 · 22 citations · 3 references

Concepts

Abstract

A low-noise FET analogue switch is described which has been used to deal with some of the problems encountered in optimizing the design of a probe for a pulsed NMR spectrometer intended for work on solids. The switch circuit has been used in association with two spectrometers, one for microsecond RF pulses and the other for RF pulsewidths of up to 1 s. In each case the resolution time achieved was limited by the transmitter coil ring down. The switch has negligible insertion loss when on and 84 dB attenuation at 15 MHz when off, thus affording good protection of the receiver system.

References

3