The Power of RF Systems: The Critical Role of High-Voltage Doorknob Capacitors in NMR Probes and Power Amplifiers The radio frequency system of a nuclear magnetic resonance instrument is a key component for exciting atomic nuclei and receiving their weak signals. Its performance directly determines the instrument's sensitivity and accuracy. Both the high-power radio frequency pulses required by the transmitting coil and the low-noise amplifier at the front end of the