Method for maintaining phase coherence of transmitter and a plurality of receivers

Abstract

The invention discloses a method for maintaining the phase coherence of a transmitter and a plurality of receivers, which is characterized by comprising the following steps: adding a compensation stage in a pulse sequence; switching frequencies of all receivers to an excitation frequency at an excitation stage of the pulse sequence; switching the frequencies of all the receivers to respective sampling frequency at a data sampling stage; and switching the frequencies of all the receivers to sampling frequencies of other receivers sequentially at the compensation stage. The frequencies of all the receivers are identical at other stages of the pulse sequence; and a frequency of the transmitter is always identical with that of one of the receivers in an implementation period of the pulse sequence. The method can ensure the phase coherence of the transmitter and the plurality of receivers simultaneously; moreover, the influence of rounding errors of the frequencies of the transmitter and the receivers on phases are identical, so the phase coherence cannot be influenced.

Description

technical field [0001] The present invention relates to nuclear magnetic resonance technology, in particular to a method for maintaining phase coherence between a transmitter and multiple receivers. Background technique [0002] The transmitter and receiver are two important components of an NMR spectrometer. Wherein, the transmitter is used for transmitting radio frequency pulses, and the receiver is used for receiving nuclear magnetic resonance signals. Generally, NMR spectrometers use a frequency source on the transmitter and receiver, and the phase of the finally received NMR signal will be determined by the phase of the transmitter frequency source (hereinafter referred to as the transmitter phase) and the phase of the receiver frequency source (hereinafter referred to as receiver phase) are jointly determined. [0003] In nuclear magnetic resonance technology, the setting of related parameters such as radio frequency pulse, gradient pulse and signal acquisition and t...

AI Technical Summary

Problems solved by technology

Therefore the "wrap-around technique" does not provide a good guarantee of phase coherence between the transmitter and multiple receivers

(2), the method of the patent ZL200410053153.9 can only ensure that one of the multiple receivers is phase-coherent with the transmitter, while the other receivers are phase-incoherent with the transmitter

However, the phase difference between the transmitter and receiver 2 has changed, therefore, the requirement of equation (1) is not satisfied, and the phase of the transmitter and receiver 2 is irrelevant

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