面向智慧农业多频多模无线通信的宽带射频接收机前端电路设计  

Design of Front-end Circuit of Broadband RF Receiver for Smart Agricultural Multi-frequency Multi-mode Wireless Communication

作　　者：陈新菡 张叶茂 刘明 潘宇 CHEN Xinhan;ZHANG Yemao;LIU Ming

机构地区：[1]南宁职业技术大学智能制造学院,南宁530008 [2]广西交通设计集团有限公司,南宁530029

出　　处：《智慧农业导刊》2025年第6期1-9,共9页JOURNAL OF SMART AGRICULTURE

基　　金：广西高校中青年教师(科研)基础能力提升项目“CMOS电流模式射频接收机前端电路的设计与研究”(2022KY1012)。

摘　　要：智慧农业作为高度现代化的新型农业模式,是推动农业新质生产力发展的重要支撑。智慧农业通过大量农业生产数据的收集、传输、分析和处理,实现信息共享和协同作业。为满足智慧农业物联网(IOT)无线通信设备低成本、小型化、兼容多种通信协议、信号高保真度和低功耗的发展需求,针对智慧农业物联网技术中3G/4G/5G、LoRa、NB-IOT、ZigBee、Wi-Fi、蓝牙(Bluetooth)和RFID等通信协议应用,设计一款可以兼容上述多种频段、多种模式无线通信的宽带(0.8~5.2 GHz)射频信号接收机前端电路。基于0.18μm CMOS设计工艺,电路采用电流模式直接下变频结构,由宽带有源巴伦低噪声跨导放大器(LNTA)、电流模式无源混频器及低输入阻抗的跨阻放大器(TIA)组成,具有良好的转换增益和线性度,提高了对带外干扰的鲁棒性。通过噪声和失真消除技术提高降噪性能,采用宽带共栅-共源(CG-CS)LNTA和电流镜技术来实现更好的输入阻抗匹配和提高电路增益。采用分别由占空比为50%的I、Q两路本振信号驱动的开关管串联实现的25%占空比开关混频级,与50%占空比开关混频级相比,下变频增益提高3 dB,降低噪声系数。跨阻放大器采用跨导增强技术实现低输入阻抗和高跨阻增益,提高电流利用效率和线性度。设计的核心电路(射频和基带信号路径)功耗为24.6 mW,在0.8~5.2 GHz工作频带内的电压转换增益为33.5~35.1 dB,噪声系数(NF)为7.9~9.28 dB,输入三阶交调点IIP3为7.82~9.93 dBm。设计的高性能接收机前端电路可广泛应用于智慧农业物联网各类需要无线通信的设备电路中,助力农业生产的信息化、集约化、自动化和智能化升级。Smart agriculture,as a highly modernized novel agricultural model,constitutes a significant support for promoting the development of new-quality productivity in agriculture.Through the collection,transmission,and analysis of a vast amount of agricultural production data,smart agriculture realizes information sharing and collaborative operations.To fulfill the development requirements of low cost,miniaturization,compatibility with multiple communication protocols,high signal fidelity,and low power consumption for wireless communication devices in the Internet of Things(IoT)of smart agriculture,and in view of the application of communication protocols such as 3G/4G/5G,LoRa,NB-IOT,ZigBee,WiFi,Bluetooth,and RFID in the IoT technology of smart agriculture,a front-end circuit of a broadband radio frequency signal receiver that can be compatible with multiple frequency bands and multiple modes of wireless communication mentioned above has been designed.A wideband(0.8~5.2 GHz)CMOS current-mode RF direct downconversion receiver front-end architecture is proposed in this paper,which consists of a low noise transconductance amplifier(LNTA),a passive mixing stage and a transimpedance amplifier(TIA).The low noise transconductance amplifier uses a common gate-common source(CG-CS)parallel structure,noise and distortion cancellation technology and current mirror technology.The passive mixer adopts orthogonal mixing structure and is driven by 25%duty cycle orthogonal local oscillator(LO)signal to avoid the IQ interaction problem and further worsens the linearity and noise of the passive mixer.Compared with the 50%duty cycle switching mixer stage,the down-conversion gain is increased by 3 dB.The gm-boosting technique is adopted in TIA to achieve low input impedance and high gain,which improves the current utilization efficiency and linearity.Simulation results show that the core circuit consumes 24.6 mW,and the prototype receiver achieves approximate 33.5~35.1 dB conversion gain,7.9~9.28 dB NF,and 7.82~9.93 dBm IIP3 from 0.8 to 5.

关 键 词：智慧农业物联网 无线通信 宽带 电流模式 射频接收机前端 

分 类 号：TN402[电子电信—微电子学与固体电子学]