Review of Scientific Instruments · 1968 · 23 citations · 4 references
EngineeringElectrical EngineeringNuclear EngineeringElectronic MaterialsMicroelectronicsSemiconductor DevicesLow-noise Circuit DesignNoiseNoise In Electronic DevicesNoise In Semiconductor DevicesNoise ReductionRadio-frequency Integrated CircuitsMosfet NoiseNoise CharacteristicsNoise FigureNoise In AmplifiersNoise In Field-effect TransistorsNoise In Metal-oxide-semiconductor Field-effect TransistorsNoise SourcesShot Noise
A low temperature (4.2 K) radio frequency amplifier has been constructed using metal oxide semiconductor field effect transistors (MOSFET). Noise characteristics of the amplifier are compared to a model that includes two noise sources: shot noise and induced gate noise. The model is similar to models used to represent noise in vacuum tubes. Amplifier use for observation of low temperature nuclear magnetic resonance (NMR) signals is considered. Conditions for optimum signal-to-noise (S/N) are expressed in terms of the noise figure and are compared to those for room temperature vacuum tube amplifiers. Improvement of S/N by factors of 3 to 10 are readily obtainable. The S/N improvement with the low temperature MOSFET amplifier is demonstrated by observation of the NMR signal of 205Tl at 4.2 K at a frequency of 20 MHz.
4
Pulsed Nuclear Resonance Apparatus
W. G. Clark · Review of Scientific Instruments · 1964 · 284 citations
Natural Sciences, Nuclear Engineering, Nuclear Instrumentation +16
Field Effect Transistors at 4.2°K
Floyd E. Kingston, Kenneth Lee · Review of Scientific Instruments · 1968 · 12 citations