超音波應用中高電壓類比放大器與功率計的整合

Integration of High-Voltage Analog Amplifier with Power Meter for Ultrasound Application

楊筱凡(Xiao-Fan Yang)

指導教授 ： 馬亞尼

義守大學/醫學科技學院/生物醫學工程學系/碩士(2024年)

摘要

超音波技術在醫學、科學和工程領域不斷發展。然而，由於換能器振幅轉換的限制，通常需要使用功率放大器來提高信號振幅。換能器的振幅轉換限制是指在轉換電能為超音波信號的過程中，受到物理結構、材料特性或製造技術等因素的制約，使得生成的超音波信號可能無法達到足夠的振幅。目前市面上的超音波放大器價格相對較高，因此本研究的目的是設計一種成本較低的替代品，以滿足超音波放大器對高頻率和高電壓的需求。實驗採用了 AD8021 差分放大器和同相放大器作為前級放大器級，並使用 LT1210 橋式放大器電路作為功率放大器。結果顯示，系統的頻寬為 19.61 kHz 至 14.76 MHz，放大增益為 36.271 dB，這樣的設計旨在克服換能器振幅轉換限制，確保生成的超音波信號具有足夠的強度，同時降低研究成本，這種技術有助於擴大超音波應用的範疇，特別是在對成本敏感的應用場景中。此外，本研究中使用的功率計（Power Meter）AD8364被用來測量系統輸出的功率，以確保放大器的性能和穩定性。AD8364功率計具備高線性度和資料精度，能夠提供準確的功率測量數據，這對於確保系統在不同工作條件下的穩定性和可靠性至關重要。功率計的校準顯示出其測量結果與理論值高度一致，不僅提高了實驗效率，還提升了系統的整體性能和應用潛力，這樣的設計在保持高效能的同時，確保了系統的穩定運行。

關鍵字

超音波 ； 換能器 ； 超音波放大器 ； 高頻率 ； 高電壓 ； 功率計

並列摘要

Ultrasonic technology continues to advance in the fields of medicine, science, and engineering. However, due to the limitations of transducer amplitude conversion, power amplifiers are often needed to enhance signal amplitude. The amplitude conversion limitations of transducers refer to the constraints imposed by physical structure, material properties, or manufacturing techniques, which may prevent the generated ultrasonic signals from reaching sufficient amplitude. Currently, commercially available ultrasonic amplifiers are relatively expensive, so the goal of this study is to design a cost-effective alternative to meet the demands for high frequency and high voltage in ultrasonic amplifiers. The experiment used AD8021 differential amplifiers and non-inverting amplifiers as the preamplifier stage, and the LT1210 bridge amplifier circuit as the power amplifier. The results showed that the system's bandwidth ranged from 19.61 kHz to 14.76 MHz, with an amplification gain of 36.271 dB. This design aims to overcome the amplitude conversion limitations of transducers, ensuring that the generated ultrasonic signals have sufficient strength while reducing research costs. This technology helps expand the scope of ultrasonic applications, especially in cost-sensitive scenarios. Additionally, the AD8364 power meter used in this study measures the system's output power to ensure the amplifier's performance and stability. The AD8364 power meter, with its high linearity and data accuracy, provides precise power measurement data, which is crucial for maintaining system stability and reliability under different operating conditions. The calibration of the power meter showed that its measurement results were highly consistent with theoretical values, which not only improved experimental efficiency but also enhanced the overall performance and application potential of the system. This design maintains high performance while ensuring stable system operation.

並列關鍵字

ultrasound ； transducer ； ultrasound amplifier ； high frequency ； high voltage ； power meter

參考文獻

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