射频接收电路的改进及综合测试  

Improvement and Comprehensive Test of Receiver Circuit

作　　者：郑文杰 郝文玲 Zheng Wenjie;Hao Wenling(School of Mechanical and Electrical Engineering,Jiaozuo University,Jiaozuo,Henan 454000,China)

机构地区：[1]焦作大学机电工程学院,河南焦作454000

出　　处：《绿色科技》2022年第18期253-257,共5页Journal of Green Science and Technology

摘　　要：射频接收机作为无线通讯系统的最前端,其结构和性能直接影响整个通信系统的通信质量。射频接收电路是把天线接收进来的带有调制的射频信号转变成基带信号,再把基带信号的幅度放大后输出给基带控制板。现有的射频接收电路存在模拟灵敏度和数字灵敏度较低、失真度较高、邻道选择性较低、双信号选择性较低、互调抗扰性指标较低、一致性较差等缺点。通过改进射频接收电路的压控振荡器电路和混频器电路,以提高系统的稳定性、噪声系数、增益、灵敏度等,使电路的本振、射频与中频间的隔离性和互调性更好。通过对改进后电路进行综合测试可以看出:模拟灵敏度提高了2~4 dB,数字灵敏度提高了2~4 dB,失真度整体明显降低,邻道选择性提高了10~13 dB,双信号选择性提高了7 dB,互调抗扰性指标提高了4 dB,远端极限通话距离提高了0.5 km,改进效果明显。As the front end of wireless communication system,the structures and performance of radio frequency receiver directly affect the communication quality of the whole communication system.The RF receiver converts the modulated RF signal received by the antenna into a baseband signal,and then amplifies the amplitude of the baseband signal and outputs it to the baseband control board.The existing radio frequency receiving circuit has disadvantages such as low analog sensitivity and digital sensitivity,high distortion,low adjacent channel selectivity,low dual-signal selectivity,low intermodulation immunity index,and poor consistency.In this paper,by improving the voltage-controlled oscillator circuit and the mixer circuit of the radio frequency receiver circuit to improve the stability,noise figure,gain,sensitivity,etc.of the system,the isolation and intermodulation between the local oscillator,radio frequency and intermediate frequency of the circuit are improved.Through comprehensive testing of the improved circuit,it can be seen that the analog sensitivity is increased by 2~4 dB;the digital sensitivity is increased by 2~4 dB;the overall distortion is significantly reduced;the adjacent channel selectivity is increased by 10~13 dB,and the dual-signal selectivity is increased by 7 dB;the intermodulation immunity index is increased by 4dB,and the far-end limit call distance is increased by 0.5 kilometers with obvious improvenment dffect.

关 键 词：射频接收机电路 压控振荡器 混频器 无线通讯 

分 类 号：D261.4[政治法律—政治学]