平衡式低噪声放大器设计

发布时间：2018-04-12 14:51

本文选题：低噪声放大器 + 噪声系数　；参考：《电子科技大学》2015年硕士论文

【摘要】：低噪声放大器在无线通信、雷达、遥测遥控和电子对抗系统中作为接收机前端的第一级部件,其性能决定了接收机的抗噪声特性。如今各种科技产品不断更新换代,对低噪声、高增益、高动态范围、高可靠性的低噪声放大器的需求也越来越迫切,因此,对低噪声放大器进行研究具有重要意义。本文首先介绍了低噪声放大器的研究背景和发展现状,列举了国内外几家公司的低噪声放大器产品的性能参数,又介绍了低噪声放大器理论,包括低噪声放大器的性能指标和设计方法,然后开始对平衡式低噪声放大器进行设计、仿真、优化、绘制版图、加工实物、测试和调试。本文设计的低噪声放大器的工作频段为1.8~2.2GHz,为同时满足对噪声系数、增益和驻波比的要求,放大器采用平衡式结构。与单端低噪声放大器相比,平衡式低噪声放大器的端口匹配比较好,能够获得较好的驻波比,而且放大器的动态范围、可靠性和稳定性也得到提高,从而使噪声系数得以降低。考虑到版图设计的难度,本设计选用分支线定向耦合器。首先设计了单级平衡式低噪声放大器,晶体管选用AVAGO公司的ATF-54143,应用ADS软件对放大器的偏置电路、稳定电路和匹配电路进行了设计,并与两个定向耦合器相连构成单级平衡式低噪声放大器,经过仿真和优化,得到了合理的设计方案,加工实物后,经不断调试,最终获得了较好的测试结果,噪声系数小于0.7dB,增益大于15dB,输入输出驻波比小于1.5。为进一步提高增益,设计了两级平衡式低噪声放大器,第二级驱动放大器选用AVAGO公司的晶体管ATF-50189,通过ADS软件对驱动放大器的偏置电路、稳定电路和匹配电路进行了设计,并与第一级低噪声放大器进行级联仿真,最后将级联后的放大器与两个定向耦合器相连构成两级平衡式低噪声放大器,仿真优化后加工实物,经过反复调试,最终测得在工作频带内,放大器的噪声系数在0.67dB~0.72dB,增益为24.78dB~25.31dB,输入输出驻波比均小于1.5。
[Abstract]:Low noise amplifier (LNA) is the first stage of receiver in wireless communication, radar, telemetry, remote control and electronic countermeasure system. Its performance determines the anti-noise characteristics of receiver.This paper first introduces the research background and development status of LNA, enumerates the performance parameters of LNA products from several companies at home and abroad, and introduces the theory of LNA.It includes the performance index and design method of LNA, and then designs, simulates, optimizes, draws layout, processes objects, tests and debugs the balanced LNA.The operating frequency of the LNA designed in this paper is 1.8V 2.2GHz. In order to meet the requirements of noise coefficient, gain and VSWR simultaneously, the amplifier adopts a balanced structure.Compared with single-ended low-noise amplifier, the balanced low-noise amplifier has better port matching and better standing wave ratio, and the dynamic range, reliability and stability of the amplifier are also improved, so that the noise coefficient can be reduced.Considering the difficulty of layout design, this design chooses branch line directional coupler.First, a single-stage balanced low-noise amplifier is designed. The transistor is composed of ATF-54143of AVAGO Company. The bias circuit, stabilization circuit and matching circuit of the amplifier are designed by using ADS software.And connected with two directional couplers to form a single-stage balanced low-noise amplifier. Through simulation and optimization, a reasonable design scheme is obtained. After processing the material object, after continuous debugging, a better test result is obtained.The noise coefficient is less than 0.7 dB, the gain is greater than 15 dB, and the input / output standing wave ratio is less than 1.5.In order to further improve the gain, a two-stage balanced low-noise amplifier is designed. The second stage drive amplifier uses AVAGO transistor ATF-50189.The bias circuit, stabilization circuit and matching circuit of the drive amplifier are designed by ADS software.Finally, the cascade amplifier is connected with two directional couplers to form a two-stage balanced low-noise amplifier.Finally, in the operating frequency band, the noise coefficient of the amplifier is 0.67 dB ~ 0.72 dB, the gain is 24.78 dB ~ (-1) 25.31 dB, and the input / output VSWR is less than 1.5.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722.3

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