一种宽频带可配置数字射频调制的实现方法

摘要

In order to improve the capability of avionics system under limited size,weight and power,this paper proposes a design method of wideband reconfigurable digital radio frequency(RF) modulation,in which the digitalization is pushed to the antenna interface unit so that both the baseband and up-conversion are realized through digital signal processing.First,three transmission architectures are comparatively analyzed.Then the wideband reconfigurable transmitter framework is proposed based on the digital RF modulation transmission channel architecture.Key techniques such as N-time harmonic modulation technique,poly-phase down-sampling technique,and optimal local oscillator selection method are adopted to solve the problems in the implementation process.The results indicate that this design has better performance than traditional method.The magnitude error of RF transmitting signal is only 1.7%RMS(Percent Root Mean Square),phase error less than 1°,error vector magnitude(EVM) 2.345%RMS,and wider span of clean spectrum is achieved.%针对航空电子系统能力提升和体积重量功耗的矛盾,提出了一种宽频带可配置数字射频调制的设计与实现方法,使用数字信号处理的方法实现调制和上变频,将数字化推进到天线接口单元.首先,对比分析了3种发射信道的实现架构;其次,基于数字射频调制信道架构设计了宽频带可配置发射信道;然后,针对宽频带可配置数字射频调制在实现过程遇到的问题,一一给出了解决方法,即N次谐波调制技术、多相采样降速技术、最优本振选择方法.实现结果表明,相比传统二次发射信号的产生方案,本设计能够产生高质量的射频发射信号,幅度误差仅为1.7%RMS(Percent Root Mean Square),相位误差小于1°,误差向量幅度(EVM)仅为2.345%RMS,并具有宽频带优良的谐杂波抑制能力.