2.4GHz硅基高效率线性功率放大器的研究与设计

发布时间：2018-03-08 19:44

  本文选题：线性功率放大器　切入点：包络跟踪功率放大器　出处：《东南大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着4G-LTE无线通信技术的广泛使用,需要性能更加优越的射频发射机系统,在发射机中功率放大器的能耗最大,同时成本也很高,因此市场上对高效率高线性度和低成本的功率放大器产品需求越来越强烈,而基于硅基工艺的功率放大器,优势在于成本低廉,工艺制程先进。因此对硅基2.4GHz高效率线性功率放大器的设计展开研究具有重要的理论意义和应用价值。本文基于0.18μm SiGe BiCMOS工艺设计工作于2.4GHz的高效率线性功率放大器。整个高效率线性功率放大器由线性功率放大器和包络跟踪模块构成。线性功率放大器采用两路完全相同的AB类功率放大器合成,单路线性功率放大器采用cascode结构,以解决工艺中单HBT晶体管耐压低的问题,采用伪差分对称结构以减小寄生参数的影响。整个线性功率放大器采用分布式LC功率合成技术以提高输出功率,采用片外分立元件设计功率放大器的输入输出匹配网络。包络跟踪模块由包络检波器和包络调制器构成,其中包络检波器对射频信号进行检波,包络调制器则根据提取的包络信号对功率放大器电源电压进行动态调制,在低功率输入时,自动降低功率放大器的电源电压;在高功率输入时,自动提高功率放大器的电源电压,从而有效提升了功率放大器的效率。论文给出了线性功率放大器和包络跟踪模块的电路设计和版图设计,并进行了前仿真和后仿真。后仿真结果表明,在线性功率放大器的工作电压为5V时,TT工艺角的不同温度下,功率放大器始终处于稳定状态,S11小于-10dB,输出功率大于33dBm;在TT27℃C时,功率附加效率为42.81%,输出1dB压缩点为29.61dBm。采用包络跟踪技术的高效线性功率放大器在LTE 16QAM 5MHz信号输入时,平均输出功率为27.8dBm,此时功率附加效率为24.5%,最大输出功率时的功率增益为23.47dB,满足指标要求。因此,本课题所设计的高效线性功率放大器后仿真结果满足设计指标要求,后期需根据实际芯片的测试结果作进一步的优化和调试。
[Abstract]:With the wide use of 4G-LTE wireless communication technology, RF transmitter system with more superior performance is needed. In the transmitter, the power amplifier has the most energy consumption and the cost is also very high. Therefore, there is a growing demand for high efficiency, high linearity and low cost power amplifiers in the market, and the advantage of silicon based power amplifiers lies in their low cost. The process is advanced. Therefore, it is of great theoretical significance and practical value to study the design of Si-based 2.4GHz high efficiency linear power amplifier. This paper based on 0.18 渭 m SiGe BiCMOS process design works in 2.4GHz high efficiency linear power amplifier. The whole high efficiency linear power amplifier consists of a linear power amplifier and an envelope tracking module. The linear power amplifier is composed of two identical AB power amplifiers, The single channel linear power amplifier adopts cascode structure to solve the problem of low voltage resistance of single HBT transistor. The pseudo-differential symmetry structure is used to reduce the influence of parasitic parameters. The whole linear power amplifier uses distributed LC power combination technology to improve the output power. The input and output matching network of the power amplifier is designed by using an off-chip discrete element. The envelope tracking module is composed of an envelope detector and an envelope modulator, in which the envelope detector detects the RF signal. The envelope modulator dynamically modulates the power supply voltage of the power amplifier according to the extracted envelope signal, and automatically reduces the power supply voltage of the power amplifier at low power input. In order to improve the efficiency of power amplifier, the circuit design and layout design of linear power amplifier and envelope tracking module are given. The results of pre-simulation and post-emulation show that the power amplifier is always in a stable state (S11 < -10dB, output power more than 33dBm) at different temperatures of TT process angle when the operating voltage of the linear power amplifier is 5V, and the output power is more than 33dBm at TT27 鈩，

本文编号：1585290