Phase calibration structure of magnetic resonance radio frequency power amplifier

Abstract

The invention relates to a phase calibration structure of a magnetic resonance radio frequency power amplifier. The magnetic resonance radio frequency power amplifier comprises power amplification modules of N power amplifier tubes and a power synthesis module, wherein the power synthesis module is used for power amplification and synthesis of N input signals. The phase calibration structure is characterized by comprising N phase shifters, N phase discriminators and N directional couplers; each input signal of N input signals is connected with one phase shifter and then connected with an input end of one power amplifier tube in one power amplification module, an output end of the power amplification tube is connected with an input end of one directional coupler, and an output end of the directional coupler is connected with one phase discriminator and then connected with a phase shifter input end corresponding to the signal; besides, output ends of all the power amplifier tubes are connected with the power synthesis module. The phase calibration structure has the advantages as follows: the phase difference generated by the power amplifier tubes is automatically compensated, phases of the output signals are consistent, and the optimum synthesis efficiency is realized.

Description

technical field [0001] The invention relates to a phase calibration structure of a magnetic resonance radio frequency power amplifier. Background technique [0002] The structure of the current magnetic resonance radio frequency power amplifier is shown in the appendix figure 1 As shown, the input signal is S1(in)=S2(in)=...=Sn(in), each input signal passes through a power amplifier tube, and the input signal is amplified to S1(out), S2(out), Sn (out). Theoretically, we hope that after the input signals of N channels pass through the power amplifier tube, the output signals obtained are also completely equal. Each input signal and output signal have two variables, one is the gain and the other is the phase; but in fact, due to various power The inconsistency of the amplifier tubes, especially the power of the nuclear magnetic resonance radio frequency power amplifier tubes is relatively large, and a single power amplifier tube can reach more than 1.5KW, so it is difficult ...

AI Technical Summary

Problems solved by technology

Theoretically, we hope that after the input signals of N channels pass through the power amplifier tube, the output signals obtained are also completely equal. Each input signal and output signal have two variables, one is the gain and the other is the phase; but in fact, due to various power The inconsistency of the amplifier tubes, especially the power of the nuclear magnetic resonance radio frequency power amplifier tubes is relatively large, and a single power amplifier tube can reach more than 1.5KW, so it is difficult to ensure that when the amplitude and phase of the input signal of each power amplifier tube remain the same, The phase and amplitude of the obtained output signal are also consistent

Therefore, although the phase and amplitude of the input signal are the same, after passing through the power amplifier tube, the phase and amplitude are different, and the different signals are then vector synthesized by the synthesizer, resulting in the final output result and the expected design result produce large deviation

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