MRI RF Amplifier Envelope Correction for Rising Delay Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Magnetic Resonance Imaging (MRI) apparatuses face challenges in precisely reproducing the waveform of amplified radio frequency (RF) signals due to delays in the rising characteristic of amplifying circuitry, which affects the accuracy of RF signal amplification and timing control, especially in methods requiring short pulse durations like Ultrashort TE (UTE) imaging.
Innovation Solution
The RF amplifying device includes obtaining circuitry to digitize the RF signal envelope, correcting circuitry to adjust the envelope based on the amplifying circuitry's rising characteristic, and amplifying circuitry to output an amplified signal that compensates for the delay, ensuring precise waveform reproduction and timing control by generating the RF input signal with increased amplitude during the initial delay period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional amplifying circuitry is used to amplify RF signals, then the amplification process is simple and direct, but the rising characteristic delay causes waveform reproduction inaccuracy and timing control errors
Solution Approach 1:
The system performs preliminary measurement of the rising characteristic before actual RF signal amplification. The measurement unit measures the time from when the amplifying circuitry starts amplifying a measurement signal to when the amplified signal reaches a predetermined level, and this measurement is used to set the start timing of the RF signal amplification in advance, compensating for the rising delay
Solution Approach 2:
The system uses feedback by measuring the actual rising characteristic of the amplifying circuitry and using this measured information to adjust and set the start timing of RF signal amplification. The measurement unit provides feedback data about the delay time, which is then used by the control mechanism to compensate for the rising delay in subsequent operations
2Manufacturing precision
If the amplifying circuitry operates without pre-measurement and timing adjustment, then the operation is fast and simple, but the waveform of the amplified RF signal cannot be reproduced with high precision
Solution Approach 1:
The measurement unit measures the rising characteristic in advance before actual RF signal amplification operations. By performing this measurement beforehand and using the results to set the start timing, the system achieves precise waveform reproduction without adding complex real-time control mechanisms during the actual amplification process
Solution Approach 2:
The amplifying device performs self-characterization by measuring its own rising characteristic through the measurement unit. The system uses its own internal resources to measure and compensate for its inherent delays, eliminating the need for external calibration equipment or complex external control systems
3Measurement precision
If the rising delay of amplifying circuitry is not compensated, then the system operation is straightforward, but timing control accuracy deteriorates in short pulse duration methods like UTE imaging
Solution Approach 1:
The system measures the rising characteristic in advance and uses this information to set the start timing of RF signal amplification before the actual imaging sequence begins. This preliminary timing adjustment ensures that the timing control accuracy required for short pulse duration methods like UTE imaging is achieved
Solution Approach 2:
The system performs preliminary compensation for the rising delay by adjusting the start timing in advance. By measuring the delay and setting the timing beforehand to counteract this delay, the system eliminates the harmful effect of rising delay on timing control accuracy in precision-sensitive applications
Data Source
AI summary
A radio frequency amplifying device according to an embodiment includes amplifying circuitry, obtaining circuitry, and correcting circuitry. The amplifying circuitry is configured to output an amplified signal obtained by amplifying a signal input thereto. The obtaining circuitry is configured to obtain an envelope indicating a waveform of a radio frequency signal as digital data. The correcting circuitry is configured to correct the obtained envelope on the basis of a rising characteristic of the amplifying circuitry and to input the signal generated on the basis of the envelope resulting from the correction to the amplifying circuitry.