Spin resonance spectrometer for nuclear magnetic resonance (NMR) uses loads tuned to third order harmonics of base frequency

摘要

NMR spectrometer has an oscillator (12) driving a modulator (13) controlled by a pulse generator (14) to drive an amplifier (16). The amplifier output is filtered (18) and used to drive a probe head (20). The input to the filter is connected to another filter (30) tuned to the third harmonic and connected to a load (32), e.g. 50 Ohm. A similar filter and load can be connected to the output of the main filter and may be tuned at a higher frequency.