SiGe HBT低噪声放大器的研究

发布时间：2018-08-07 08:23

【摘要】：作为在CMOS工艺与Ga As上价格与性能折衷的工艺,SiGe HBT(Hetrojunction bipolar transistor,HBT)工艺具有非常优良的应用前景。该工艺结合射频应用,依靠高性能的器件可设计出多种射频通信电路,其中以低噪声放大器电路(Low noise amplifier,LNA)最具代表性。作为接收机最前端的核心电路,低噪声放大器需要在增益、匹配、噪声系数和线性性能之间进行多种折衷,该电路性能的优良与否决定了接收机的整体性能。而针对目前热门研究的X,Ku波段接收机和更高频率的微波级电路,该电路的研发难度更大。本文对SiGe HBT晶体管的模型和LNA电路做了较为深入的研究,其中的主要创新有:分析了SiGe HBT的工艺特性以及双极型晶体管小信号模型,提出SiGe Hicum器件主要噪声贡献源,并在此基础上分析双端口网络在电路噪声方面的应用,同时针对电路级网络提出噪声优化方法。针对SiGe HBT工艺,在双极型晶体管小信号基础上提出了SiGe工艺下的小信号模型,并结合物理模型应用Hicum模型提出SiGe晶体管的噪声模型,基于对双端口网络分析基础提出多端口噪声网络分析理论,该理论可应用在电路级分析上,不局限于单器件晶体管分析,为低噪声放大器设计提出扎实的理论指导。分析了SiGe低噪声放大器的几个重要指标:输入匹配、增益平坦度以及线性特性。设计出一四阶片上滤波匹配网络,对该结构的电路优化使得输入匹配和噪声性能达到最佳折中。在增益平坦方面,分析了匹配与网络噪声相关问题,并采用片上电感补偿以及零极点方法,设计出一四阶6~14GHz低噪声放大器,该电路增益仅有0.4dB的波动。根据增益分配原理分配优化了各级增益,避免了单级增益过冲效应以及线性性能恶化,同时电路在输入端还采用了并联-并联负反馈结构,确保输入匹配,该电路在第三级通过电感引入一个额外的零点,来补偿极点滚降,同时采用的局部负反馈和整体负反馈这一思想实现通带噪声平坦,增益平坦、频带展宽等特性。针对SiGe器件线性度差这一问题,根据晶体管弱非线性模型,提出利用双极型晶体管的非线性模型,结合Volterra级数进行单级SiGe低噪声放大器线性性能优化的方法,并根据维塔里序列提出线性度的分析方法,并量化出各个参数在线性度方面的贡献,使得双极LNA在超宽频下具有-7.7dBm的IIP3性能。设计UWB频带和X,Ku波段的超宽带SiGe低噪声放大器。对UWB系统的LNA在噪声平坦方面做了研究,提出基于品质因子优化方式的噪声平坦化方法。而对X,Ku波段低噪声放大器的电路设计工作中则更侧重于完整的设计流程,对相应电路的输入匹配、增益以及线性度和噪声分别提出分析和优化方法,同时提出射频版图的常见问题及优化方法,在电路设计、优化的基础上提出高频电路的测试方法,对射频电路的测试方法流程加以详述,对结果进行分析讨论,着重论述S参数测量,噪声测量以及线性度测量。该LNA在应用频带可实现16dB的增益以及4dB以下的噪声系数,而1dB压缩点也实现了-18dBm。针对镜频抑制型接收机,设计两款适用于不同应用频带的SiGe具有镜频抑制功能的低噪声放大器结构。其中,K频带的低噪声放大器采用的无源滤波结构实现了33.6dB的镜频抑制比和19d B的增益;第二款低噪声放大器则通过片上有源镜频滤波器实现了33dB的镜频抑制比,具有很好的实用性和理论指导意义。本文较为详细和完备地讲述了SiGe HBT低噪声放大器的设计流程与设计方法,通过多种实例详细地从理论和设计方面阐述了电路设计工作。在增益、匹配、线性度和噪声等指标方面均通过实例加以分析和说明,为LNA电路设计提供重要的理论指导和设计思路。
[Abstract]:As a process to compromise the price and performance of CMOS technology and Ga As, SiGe HBT (Hetrojunction bipolar transistor, HBT) technology has a very good application prospect. This process combines RF applications and designs a variety of RF communication circuits based on high performance devices. Among them, low noise amplifier circuits (Low noise amplifier) are the most important. Representative. As the core circuit of the front end of the receiver, the low noise amplifier requires a variety of tradeoffs between gain, matching, noise coefficient and linear performance. The performance of the circuit determines the overall performance of the receiver. The X, Ku band receiver and the higher frequency microwave level circuit for the current hot research, the electric circuit The road is more difficult to develop. This paper makes a more in-depth study of the SiGe HBT transistor model and LNA circuit. The main innovations are as follows: the process characteristics of SiGe HBT and the bipolar transistor small signal model are analyzed, and the main noise contributors of the SiGe Hicum devices are proposed. On this basis, the dual port network is analyzed in the circuit noise side. On the basis of the SiGe HBT process, a small signal model of the SiGe process is proposed on the basis of the bipolar transistor small signal, and the noise model of the SiGe transistor is proposed with the physical model of the Hicum model, based on the physical model, and the multi port noise network is proposed based on the analysis of the dual port network. The theory of the collaterals, which can be applied to the analysis of the circuit level, is not limited to the single device transistor analysis, and provides a solid theoretical guidance for the design of the low noise amplifier. Several important indexes of the SiGe low noise amplifier are analyzed, including input matching, gain flatness and linear specificity. The 14 order filter matching network is designed. The circuit optimization of the structure makes the input matching and noise performance best compromise. In the aspect of gain flatness, the problem of matching and network noise is analyzed, and the 14 order 6~14GHz low noise amplifier is designed by using on chip inductance compensation and zero pole method. The gain of the circuit is only 0.4dB, according to the gain allocation principle. At the same time, a parallel parallel negative feedback structure is used at the input end to ensure the input matching. The circuit introduces an extra zero point through the inductor at the third stage to compensate the pole roll drop, and the local negative feedback and the whole negative feedback are used at the same time. In view of the linear degree difference of SiGe devices, a method to optimize linear performance of single stage SiGe low noise amplifier based on the nonlinear model of bipolar transistors is proposed in accordance with the weak nonlinear model of transistors. According to the weak nonlinear model of transistor, the linear performance optimization method of single stage SiGe low noise amplifier is carried out based on the Volterra series. The analysis method of linear degree is proposed, and the contribution of each parameter online degree is quantified, which makes the bipolar LNA have the IIP3 performance of -7.7dBm under ultra wide frequency. Design UWB band and X, Ku band ultra wideband SiGe low noise amplifier. The LNA in UWB system is studied in noise flatness, and the noise based on quality factor optimization is proposed. In the circuit design of X, Ku band low noise amplifier, the design process of the low noise amplifier is more focused on the complete design process. The input matching, gain, linearity and noise of the corresponding circuit are analyzed and optimized respectively. At the same time, the common questions and optimization methods of the radio frequency layout are put forward, on the basis of the circuit design and optimization. The test method of high frequency circuit is put forward, the test method flow of RF circuit is described in detail, the results are analyzed and discussed. The S parameter measurement, noise measurement and linearity measurement are emphasized. The LNA can achieve the gain of 16dB and the noise coefficient below 4dB in the applied frequency band, and the 1dB compression point also realizes the -18dBm. suppression for the mirror frequency. The type receiver is designed for two types of low noise amplifier structures for SiGe with the function of mirror frequency suppression for different application bands. Among them, the passive filter structure used by the K frequency band low noise amplifier realizes the 33.6dB mirror frequency suppression ratio and the gain of 19d B; the second low noise amplifier realizes 33d through the active mirror filter on the chip. The mirror frequency suppression ratio of B is of good practicability and theoretical guidance. The design process and design method of SiGe HBT low noise amplifier are described in detail and well. The circuit design work is expounded in detail from the theory and design aspects by a variety of examples. It is common in the aspects of gain, matching, linearity and noise. An example is given to analyze and illustrate, providing important theoretical guidance and design ideas for LNA circuit design.
【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN722.3

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