【作者】 杨帆；

【导师】 陈鹏；

【作者基本信息】 东南大学 ， 电磁场与微波技术， 2020， 硕士

【摘要】 微波毫米波在现代科技社会的信息传递中占据着十分重要的地位。与此同时,自组网通信系统逐渐崭露头角。自组网中每一个终端都具有主机和路由器两种功能,可实现信息传递的网络化和便捷化。由于信号不仅需要在基带进行多种处理而且还需要在较高频段进行传输,于是存在上下变频这一问题。信号的发射和接收是信息传输的重要环节,基于此,本文研制了一个Ku波段的时分双工上下变频收发器,可将低频信号混频至较高频段进行发送,同时可接收高频信号并混频至较低频段进行处理。针对变频收发系统展开以下几个方面的工作。首先,课题指标要求发射通路上将-20d Bm的1GHz信号上变频至20d Bm的Ku波段14GHz～16GHz信号进行发送;接收通路上将接收到-5d Bm的Ku波段射频信号,并下变频至1GHz。经研究分析,确定了两次变频的系统方案,将1GHz信号首先变频至4GHz,再与10GHz～12GHz的本振信号混频至14GHz～16GHz。并利用单刀双掷开关完成上下两路的选择切换。然后,对论文设计中所需的滤波器进行设计仿真。本文设计了4个滤波器,分别为4GHz扇形低通滤波器、4GHz交指带通滤波器、14GHz～16GHz交指带通滤波器和14GHz～16GHz基片集成波导滤波器。课题使用Wasp-net的快速设计向导功能完成基片集成波导滤波器的设计流程,提高了设计效率。对14GHz～16GHz基片集成波导滤波器进行测试,测试结果满足设计要求。最后,对上下变频收发器的细节进行设计仿真,调整细节直至链路预算结果满足课题指标要求,确定系统的具体框图并制作实物。软件程序包括PC端程序和单片机固件,并结合硬件进行实物测量。上变频链路测试结果中,输出14GHz～16GHz的范围内功率均在19.2d Bm以上,平坦度为3d B,输出三阶交调截取点约为30d Bm,输出15GHz处相位噪声为-86.12 d Bc/Hz@10KHz。下变频链路在输入-5d Bm的14GHz～16GHz范围内输出1GHz功率均在-9.7d Bm以上,平坦度为2.8d B,输出三阶交调截取点约为8d Bm,输入15GHz时输出1GHz处相位噪声为-92.5 d Bc/Hz@10KHz。输入-5d Bm的6GHz～8GHz信号,镜频抑制度约为88d Bc。在实验环境允许的误差范围内,上下变频器的测试结果满足设计要求,可用于工程实现。更多还原

【Abstract】 Microwave and millimeter wave plays an important role in the information transmission of modern science and technology society.At the same time,the ad-hoc network communication system is gradually emerging.Each terminal in ad-hoc network has two functions of host and router,which can realize the networking and convenience of information transmission.Because the signal needs to be processed in baseband and transmitted in higher frequency,there is the problem of up and down conversion.The transceiver system is one of the important links of information transmission.Based on this,this paper develops a Ku band time division duplex up and down conversion transceiver channel,which can mix the low-frequency signal to the higher frequency band for transmission,at the same time,it can receive the high-frequency signal to the lower frequency band for processing.The following work is carried out for the frequency conversion transceiver system.First of all,the target of the project is to up-convert 1GHz signal of-20 d Bm to 14GHz～16GHz of 20 d Bm for transmission.At the same time,it can receive RF signal in Ku band of-5d Bm and down-convert it to 1GHz.After analysis,the link scheme of two frequency conversion is determined.The 1GHz signal is first converted to 4GHz,and then mixed with the local oscillator signal of 10 GHz ～ 12 GHz to 14 GHz ～ 16 GHz.The project uses the SPDT Switch to complete the up and down selection switch.Then,the filter needed in the project is designed and simulated.In this paper,four filters are designed,which are 4GHz sector low-pass filter,4GHz interdigital band-pass filter,14GHz～16GHz interdigital band-pass filter and 14GHz～16GHz Substrate Integrated Waveguide(SIW)filter,respectively.In this project,the fast design wizard function of wasp-net is used to complete the design process of the SIW filter,which improves the design efficiency.The test results of 14GHz～16GHz SIW filter meet the design requirements.Finally,the details of the up and down conversion transceiver link budget are designed and simulated.The details are adjusted until the link budget results meet the requirements of the subject.The specific block diagram of the system is determined and the converter is fabricated.The software consists the PC side program and firmware of microcontroller unit,and then the physical measurement is carried out.The measurement result shows that in the up conversion link,the output power is above 19.2d Bm in the frequency range of14GHz～16GHz,the flatness is 3d B,and the output third-order intermodulation intercept point is about 30 d Bm.When the output frequency is 15 GHz,the phase noise is-86.12 d Bc /Hz@10KHz.The test results of down conversion link shows that the output power is above-9.7d Bm with the input frequency range is 14GHz～16GHz of-5d Bm.The flatness is 2.8d B,and the output third-order intermodulation intercept point is about 8d Bm.When the output frequency is 1GHz,the phase noise is-92.5 d Bc/Hz@10KHz with the input frequency is15 GHz.The mirror frequency rejection of 6GHz～8GHz with the input power is-5d Bm is about 88 d Bc.Within the allowable error range of the experimental environment,the test results of the up and down conversion system meet the design requirements and it is suitable for engineering realization.更多还原