【摘要】：伴隨著現(xiàn)代聲納技術(shù)發(fā)展,水聲發(fā)射機(jī)發(fā)射的信號(hào)帶寬越來(lái)越寬,這使水聲寬帶匹配成為了水聲發(fā)射機(jī)的關(guān)鍵技術(shù)之一。由于水聲換能器的阻抗存在電抗,且隨頻率的改變而不規(guī)則變化,這使得傳統(tǒng)的窄帶匹配方法很難適用。本課題針對(duì)水聲寬帶匹配所面臨的問(wèn)題,提出了將實(shí)頻法引入水聲寬帶匹配并進(jìn)行改進(jìn)。通過(guò)對(duì)傳統(tǒng)寬帶匹配理論博德-范諾-尤拉理論的研究,確定了匹配時(shí)的相關(guān)限制,驗(yàn)證了實(shí)頻法引入到寬帶匹配的正確性。本課題對(duì)實(shí)頻法的基本原理和改進(jìn)方向進(jìn)行了分析總結(jié),詳細(xì)的推導(dǎo)了原始實(shí)頻法和簡(jiǎn)易實(shí)頻法的運(yùn)算過(guò)程。在總結(jié)前人的基礎(chǔ)上提出了相應(yīng)的改進(jìn),這些改進(jìn)主要體現(xiàn)在:添加非最小電抗、增加使用優(yōu)化帶外阻抗和基于TPG(傳輸功率增益)函數(shù)的進(jìn)一步推導(dǎo)。改進(jìn)完成后通過(guò)特定負(fù)載模型的仿真驗(yàn)證了改進(jìn)的正確性。無(wú)論是原始實(shí)頻法還是改進(jìn)后的實(shí)頻法都無(wú)法避免的是網(wǎng)絡(luò)拓?fù)浜瘮?shù)的優(yōu)化,實(shí)頻法一般采用最小二乘法。本課題嘗試采用遺傳算法,遺傳算法能夠找到全局最優(yōu)解且比較穩(wěn)定,優(yōu)化效果更佳,能提升寬帶匹配的性能。在水聲學(xué)中常把寬帶匹配網(wǎng)絡(luò)、換能器和水聲功率放大器放在一起設(shè)計(jì)實(shí)現(xiàn),它們是構(gòu)成水聲發(fā)射機(jī)的重要組成部分。水聲功率放大器的作用是將信號(hào)發(fā)生源發(fā)出的信號(hào)進(jìn)行放大,輸出給下一級(jí)。它可以看做匹配電路雙端網(wǎng)絡(luò)的左端激勵(lì)源,是寬帶匹配最好的驗(yàn)證載體。本課題根據(jù)項(xiàng)目需求,實(shí)際設(shè)計(jì)了AB類功放和D類功放。在設(shè)計(jì)D類功放時(shí),功率放大器件選用IGBT代替常見的MOSFET。提升了D類功放的最大功率限制,使其更加符合大功率放大電路的需要。最后從實(shí)際應(yīng)用出發(fā),本課題以實(shí)際項(xiàng)目中的換能器ZT40-16等為負(fù)載,采用改進(jìn)后的實(shí)頻法,設(shè)計(jì)實(shí)現(xiàn)了引入寬帶匹配網(wǎng)絡(luò)電路的水聲發(fā)射機(jī)設(shè)計(jì)與實(shí)現(xiàn)。通過(guò)MATLAB仿真與阻抗分析儀4294A的實(shí)際測(cè)試,驗(yàn)證了匹配網(wǎng)絡(luò)的有效性。將匹配電路引入到水聲發(fā)射機(jī)中,通過(guò)對(duì)其輸出效率及聲源級(jí)的測(cè)試表明寬帶匹配網(wǎng)絡(luò)大大的提升了水聲發(fā)射機(jī)的性能。
[Abstract]:With the development of modern Sonar technology, the signal bandwidth of underwater acoustic transmitter is getting wider and wider, which makes underwater acoustic broadband matching become one of the key technologies of underwater acoustic transmitter. Because the impedance of underwater acoustic transducer has reactance and varies irregularly with the change of frequency, the traditional narrow band matching method is difficult to apply. In this paper, aiming at the problems of underwater acoustic broadband matching, the real frequency method is introduced into underwater acoustic broadband matching and improved. Through the study of the traditional broadband matching theory Bod-van Noir-Eula theory, the related limitations of matching are determined, and the correctness of the introduction of real frequency method into broadband matching is verified. In this paper, the basic principle and improvement direction of the real frequency method are analyzed and summarized, and the operation process of the original real frequency method and the simple real frequency method is deduced in detail. On the basis of summing up the predecessor, the corresponding improvements are put forward, which are mainly reflected in the addition of non-minimum reactance, the increase of the use of optimized out-of-band impedance and the further derivation based on TPG (Transmission Power gain) function. After the improvement is completed, the correctness of the improvement is verified by the simulation of a specific load model. Both the original real frequency method and the improved real frequency method can not avoid the optimization of network topology function, and the real frequency method generally adopts the least square method. In this paper, genetic algorithm is used to find the global optimal solution and is stable, the optimization effect is better, and the performance of broadband matching can be improved. In underwater acoustics, broadband matching network, transducer and underwater acoustic power amplifier are often designed and implemented together, and they are an important part of underwater acoustic transmitter. The function of underwater acoustic power amplifier is to amplify the signal from the signal generator and output it to the next stage. It can be regarded as the left excitation source of the two-terminal network of matching circuit, and it is the best verification carrier of broadband matching. According to the requirements of the project, AB type power amplifier and class D power amplifier are designed in this paper. In the design of class D power amplifier, IGBT is selected to replace the common MOSFET.. The maximum power limit of class D amplifier is increased, which makes it more in line with the needs of high power amplifier circuit. Finally, based on the practical application, the design and implementation of underwater acoustic transmitter with broadband matching network circuit is designed and implemented by using the improved real frequency method and the transducer ZT40-16 in the actual project. The effectiveness of the matching network is verified by MATLAB simulation and the actual test of impedance analyzer 4294A. The matching circuit is introduced into the underwater acoustic transmitter. Through the test of its output efficiency and sound source level, it is shown that the broadband matching network greatly improves the performance of the underwater acoustic transmitter.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：TB565.1
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本文編號(hào)：2477016