Preamplifier of high-field nuclear magnetic resonance spectrometer 1H/19F channel

Abstract

The invention discloses a preamplifier of a high-field nuclear magnetic resonance spectrometer 1H / 19F channel, relating to a preamplifier of a nuclear magnetic resonance spectrometer. The invention provides the preamplifier of the high-field nuclear magnetic resonance spectrometer 1H / 19F channel, with simple structure, low noise factor, high in-band gain flatness, wide amplifying linear range, high transmitting and receiving switching speed of radio-frequency switch, high cut-off isolation, accurate and sensitive working condition detection function and high stability. The preamplifier is provided with a radio-frequency switch circuit, a radio-frequency switch control circuit, a fore-end matching circuit, a front-end amplifying protecting circuit, an amplifying circuit, an input matching network, a working condition detection circuit and a DC biasing circuit. The preamplifier can satisfy the high-performance requirements of signal detection amplification of the traditional high-field nuclear magnetic resonance spectrometer 1H / 19F channel, and the values of basic capacity elements, basic inductance elements and the like in the circuits are regulated to realize different working frequency bandwidths and satisfy the concrete requirements of resonant frequency high-field spectrometers.

Description

technical field [0001] The invention relates to a preamplifier of a nuclear magnetic resonance spectrometer, in particular to a preamplifier applied to a high-field nuclear magnetic resonance spectrometer 1 H / 19 F channel high sensitivity and high stability preamplifier. It can be applied to 300-600MHz high-field nuclear magnetic resonance spectrometer. Background technique [0002] The preamplifier is an important part of the radio frequency transceiver unit of the nuclear magnetic resonance spectrometer, and is located at the front end of the system. During signal reception, the free induction attenuation signal from the probe is low-noise amplified and transmitted to the next-level components of the system receiving channel; during radio frequency pulse transmission, as the front end of the transmission channel, high-power pulses are sent to the probe coil. The noise performance of the preamplifier has a decisive effect on the noise performance of the entire receiver,...

AI Technical Summary

Problems solved by technology

Public information such as user manuals provided by these two companies shows that the 1H / 19F channel preamplifier of Varian’s high-field NMR spectrometer has a simple structure, but it has no working status indication and detection functions, so it is impossible to judge the status of the spectrometer when it is working. However, the structure of the 1H / 19F channel preamplifier of the high-field NMR spectrometer of the German Bruker company is relatively complicated, especially in the quarter wavelength of the front-end protection circuit of the amplifying The structure of the line and state detection circuit is complex, which may not only introduce unnecessary interference, but also increase insertion loss and fault error rate, thus affecting the overall stability of the system

Images