微波等离子体光源可变增益功率放大器设计研究

发布时间：2018-05-21 02:45

本文选题：微波等离子体光源 + 微波功率放大器　；参考：《电子科技大学》2016年硕士论文

【摘要】：微波等离子体光源(Light Emitting Plasma,简称LEP)是一种由微波驱动的具有连续光谱的新型光源,诞生于上世纪九十年代。具有高效、节能、光谱连续近似自然光等优点,光效高达115-150lm/w。新型LEP光源以固体微波功率源模块提供微波能,微波功率源模块主要包括:扫频源、可变增益微波放大链路、耦合检波部分和控制部分。本文主要研究用于微波等离子体光源的可调增益射频功率放大器,是可变增益微波放大链路中的前级部分,主要包括预驱动级、驱动级和电可调衰减器三部分,其主要为最后的末极放大器提供相应功率的输入信号,并根据反馈回路要求对输出功率进行自动调节。具体技术指标为:工作带宽420MHz~470MHz,输出功率大于30dBm,增益大于30dB,衰减量调节范围大于10dB。本文从电路设计和板图方面对射频功率放大器进行了详细的分析,给出了射频功率放大器的一般设计方法;利用ADS软件仿真了功率放大器的稳定性、偏置电路、输入输出匹配电路,分别进行了小信号S参数仿真和大信号谐波平衡仿真;分析了电调衰减器的工作原理,仿真了电调衰减器在所用频率下的性能参数;使用Protel99软件布线设计板图。使用AutoCAD2004软件设计了结构件。最后对本文设计的功率放大器进行了实际加工,并分模块调试了电源部分、预驱动级、驱动级和电可调衰减器,在各模块满足设计指标后对整体系统进行了测试。其中,电源部分需要五路电源,本文利用电源稳压芯片为其中的四路供电,另外一路单独供电;预驱动级部分,输出功率为3W时,功率增益约为15.8dB,输出功率4W时,功率增益约为14.3dB;驱动级部分,小信号增益较为平坦为20dB左右。输入功率超过-1dBm增益压缩较为明显,这与驱动放大器18.5dBm的P1dB一致,输入功率增大到3dBm时,增益压缩超过2dB,增益约为17.7dB;电可调衰减器部分,衰减电压分别选择0V和20V,衰减量分别为15.2dB和3.0dB。最终整体系统的测试结果表明:在工作频带范围内,输入功率为0dBm时,输出功率均大于32.5dBm,增益大于32.5dB,衰减量调节范围大于12.2dB,系统满足设计要求。
[Abstract]:Light Emitting Plasma (LEP) is a new type of light source driven by microwave, which has continuous spectrum. It was born in the 90s of last century. It has the advantages of high efficiency, energy saving and continuous spectral approximation of natural light. The light effect up to the 115-150lm/w. new LEP source provides microwave energy with the solid microwave power source module. The power source module mainly includes the sweep frequency source, the variable gain microwave amplification link, the coupling detection part and the control part. This paper mainly studies the adjustable gain RF power amplifier for the microwave plasma source. It is the front stage part of the variable gain microwave amplification link, mainly including the pre drive stage, the drive level and the electrically adjustable attenuator three. Part, mainly for the final terminal amplifier to provide the input signal of the corresponding power, and automatically adjust the output power according to the feedback loop. The specific technical specifications are: working bandwidth 420MHz~470MHz, output power greater than 30dBm, gain greater than 30dB, the decrement range is greater than 10dB.. The RF power amplifier is analyzed in detail, and the general design method of the RF power amplifier is given. The stability of the power amplifier, the bias circuit and the input and output matching circuit are simulated by the ADS software. The simulation of the small signal S parameters and the harmonic balance simulation of the large signal are carried out respectively, and the working principle of the electric attenuator is analyzed. The performance parameters of the electric attenuator at the frequency used are true; the Protel99 software is used to design the board diagram. The structure parts are designed using the AutoCAD2004 software. Finally, the power amplifier designed in this paper is actually processed, and the power supply part, the pre drive stage, the drive level and the electric adjustable attenuator are debugged in modules, and the design is satisfied in each module. After the index, the whole system is tested. Among them, the power supply needs five circuit power supply. In this paper, the power supply voltage regulator chip is used for power supply of four channels, and the other way is powered separately. The power gain is about 15.8dB when the output power is 3W, the power gain is about 14.3dB when the output power is 4W, and the drive level part, small signal gain More flat is about 20dB. The input power over -1dBm gain compression is more obvious. This is consistent with the P1dB of the driving amplifier 18.5dBm. When the input power increases to 3dBm, the gain compression is more than 2dB, the gain is about 17.7dB; the electrical attenuator part, the attenuation voltage is selected for 0V and 20V respectively, and the decrement is the 15.2dB and 3.0dB. system respectively. The test results show that when the input power is 0dBm, the output power is more than 32.5dBm, the gain is more than 32.5dB and the regulation range of the attenuation is more than 12.2dB, and the system meets the design requirements.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN722.75

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