连续型功率放大器的研究

发布时间：2018-03-22 12:05

本文选题：功率放大器　切入点：阻抗解空间　出处：《电子科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：为满足未来无线通信系统对海量数据高速率传输的要求,通信系统中的关键设备——功率放大器(功放),承载了越来越多的期待,包括高效率、宽频带、数字化等指标要求。连续型功率放大器在效率提升、带宽拓展、线性改善等方面具有巨大潜力,对其进行研究有利于高性能功放的设计。本文将以基本的连续型模型为开端,推导出具有更丰富解空间、更广适用面的各类连续型模型。本文主要研究内容及创新点总结如下:1、本文对各类传统的连续型模型进行了归纳总结,对其电压、电流时域波形以及各自的阻抗解空间进行对比。基于最新的混合连续型功放,本文提出了新型混合连续型模型,相比于前者,后者的电流电压波形均被重新塑造,最佳设计阻抗的限制条件更为宽松,匹配网络的设计难度得到进一步降低。基于这一模型,本文详细地介绍了使用低通滤波器原型设计匹配网络的方法,包括阻抗的匹配、分离元件到微带线的转换等。最后,设计了一款工作频带为2.3-3.9 GHz的功率放大器,实测漏极效率为57%-79%,增益大于9.8 dB,与近期其他连续型模型相比具有可比性。2、本文结合连续逆F类、最平坦连续逆F类等逆模型,推导了最佳基波阻抗实部可发生变化的混合连续逆模型。相比于传统逆模型,可变的基波阻抗实部能够为宽带匹配网络设计提供一个宽松的设计环境,有利于宽带高效率功放的设计。作者也分析了该功放模型输出性能随着设计空间(Design Space)拓展的变化情况,可以看出,在一定的拓展范围内,该模型仍然能够保持高效率状态。基于这一模型,作者采用阶梯阻抗变换线结构设计了一款工作在3.2-3.7 GHz的功放,单音信号测试时,其饱和漏极效率高于70%;使用5 MHz间隔的双音信号测试时,在载波互调比满足-30 dBc条件下,漏极效率大于40.3%。3、本文分析了连续类模型基于“波形工程”的高效率工作机制,对经典连续B/J类模型进行了拓展,从时域上理论地推导出了具有任意次谐波成分的电压波形。相比于连续B/J类模型中,最佳基波和谐波阻抗实部为单一阻抗的情况,所提出的模型中的基波和二次谐波阻抗的实部和虚部均能发生变化,并且能够提供多个可供选择的最佳解空间,能够满足设计者不同的场景需求。采用基于“封装工程”的匹配网络设计方法,作者计算出了最佳阻抗在封装端面的空间位置,并设计了一款2.85-4.25 GHz频段的功率放大器,饱和效率为58%-78%,漏极附加效率为54.5%-73%;在峰均比为8.6 dB的5 MHz WCDMA宽带测试信号下,当输出功率满足36 dBm时,相邻频道泄漏比为-31.5--38 dBc,平均漏极效率为38%-48%。4、本文分析了跨倍频程连续型功放设计的难点,依据拓展连续B/J类模型,设计了一款0.7-3.6 GHz跨多倍频程高效率功率放大器。在设计过程中,作者对最佳阻抗解空间的选择进行了讨论,并依据该最佳解空间进行后续功放设计;对谐波失配(包括二次谐波与三次谐波失配)对效率和匹配网络设计带来的影响进行了分析,给出了匹配网络设计时需要注意的准则,给出了二次谐波阻抗偏离最佳阻抗右侧、三次谐波通过史密斯圆图边缘靠近开路点有利于效率提升的结论;最后结合晶体管的封装网络设计了紧凑型输出匹配网络。测试结果显示,设计频带内,PAE大于47%,增益为9.6-12.6 dB,饱和输出功率大于10 W。
[Abstract]:For the requirement of massive data high-speed transmission for future wireless communication systems, the key power amplifier device in a communication system (PA), carrying more and more expectations, including high efficiency, broadband, digital and other indicators. The continuous power amplifier efficiency, bandwidth expansion, has great potential to improve linearity etc. and to study its design for high performance amplifier. This will be the basic model of continuous start with more abundant solution space is derived, more widely applicable the various continuous model. The main research contents and innovation points are summarized as follows: 1, the continuous model of the traditional summary of the voltage, current waveform and the impedance of the solution space are compared. The latest mixed continuous power amplifier based on, this paper presents a new hybrid model of continuous phase. Compared to the former, the latter is current and voltage waveform re shaping, constraints in the optimal design of impedance is more relaxed, difficult to design the matching network has been further reduced. Based on this model, this paper introduces the method of using a low-pass filter prototype matching network design, including impedance matching, separating element Microstrip line the conversion. Finally, the design of power amplifier with a working frequency of 2.3-3.9 GHz, the measured drain efficiency is 57%-79%, the gain is greater than 9.8 dB, compared with other recent continuous model is comparable to that of.2, this paper combined with continuous inverse class F, the flat continuous inverse class F inverse model, hybrid derived the best fundamental impedance can change the continuous inverse model. Compared with the traditional inverse model, the fundamental impedance variable to provide a relaxed environment for the design of broadband matching network design, is conducive to broadband The design of high efficiency power amplifier. The author also analyzes the performance of output power amplifier model with the design space (Design Space) changes, development can be seen in the development of a certain range, the model is still able to maintain high efficiency. Based on this model, the author designed a work in the 3.2-3.7 GHz power amplifier using stepped impedance transform line structure, tone signal test, the saturation drain efficiency is higher than 70%; test the two tone signal using a 5 MHz interval, -30 dBc in the carrier to intermodulation ratio to meet the conditions, the drain efficiency is greater than 40.3%.3, this paper analyzes the model based on "continuous waveform project" efficient working mechanism of classical continuous B/J class model, from the time domain theory deduces the voltage waveform with arbitrary harmonic components. Compared to the continuous B/J model, the optimal harmonic impedance for single resistance Against the situation, the real and imaginary parts of the proposed model in the fundamental and two harmonic impedance can be changed, and can provide more options for the best solution space, can meet the different needs of the scene designers. Based on "packaging" matching network design method, the author calculates the best impedance in the space position package end face, and designed a GHz band power amplifier 2.85-4.25, saturation efficiency is 58%-78%, the drain added efficiency of 54.5%-73%; in the peak to average ratio of 5 MHz WCDMA broadband test signal of 8.6 dB, when the output power to meet the 36 dBm, adjacent channel leakage ratio for -31.5--38 dBc, the average drain efficiency of 38%-48%.4, this paper analyzes the difficulties of cross octave continuous power amplifier design, based on the expansion of continuous B/J model, designed a 0.7-3.6 GHz multi octave high efficiency power amplifier in the design. In the process, the author of the best impedance of the solution space are discussed, and on the basis of the optimal solution space for subsequent design of power amplifier; harmonic mismatch (including two harmonic and three harmonic mismatch) effect on the efficiency and bring the matching network design are analyzed, the need to pay attention to the matching network design is given by criterion, gives two harmonic impedance deviation from the optimum impedance right, three harmonics by Smith chart near the edge of the open circuit point is conducive to improve the efficiency of the conclusion; finally designed a compact output matching network with network encapsulation transistor. The testing results show that the design of band PAE is greater than 47%, a gain of 9.6-12.6 dB saturation the output power is greater than 10 W.

【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN722.75

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