【摘要】 基于5.8GHz DSRC技术设计了ETC系统中的路边单元,进行了系统总体设计,并描述了RSU中天线阵列、微波接收与微波发射电路设计过程,最后给出了基带部分的单片机选型和网络接口实现方法.设计的天线为5.8GHz右旋圆极化,采用8单元微带贴片阵列,增益高于14dBi;设计的射频接收电路采用两级AGC,接收动态范围高达+5～-75dBm;提出了一种新型ASK调制电路,较之传统调制器电路简洁,调制度5%～95%连续可调;设计的发射电路功率+0.5～+31.5dBm,步进0.5dB可调,发射频率5.70～5.85GHz,步进1MHz可调.更多还原

【Abstract】 The paper presented a basic design scheme of the RSU in ETC system based on 5.8GHz DSRC technology.A further detailed design of each modules including antenna array,receiver and transmitter of microwave signals,could also be found in relevant parts of this paper.Finally an implementation of network interface and the targeted selection of MCU in base band circuit design were described in details.The microstrip antenna array designed in this paper was composed of 8units which were SMD and right-hand-circular polarized.The gain of antenna array was no less than 14dBi.RF receiver circuit worked in a form of two-stage AGC which leaded to a wider dynamic gain range up to +5to-75dBm.A new compact scheme of ASK modulation circuit with a continually adjustable modulation depth range of 5%～95% was presented.The stepping and adjustable range of transmitted power was+0.5to+31.5dBm,0.5dB;the stepping and adjustable range of frequency of transmitted signals was 5.70GHz to 5.85GHz,1MHz.更多还原