基于谐波混频的X波段频率源设计

Design of X-band frequency source based on harmonic mixing

为实现高分辨率、低相位噪声、高杂散抑制、小体积、低成本的X波段频率源,同时解决传统锁相环频率合成频率分辨率低和直接数字式频率合成输出频率低的问题,提出了一种基于谐波混频和小步进锁相环改善相位噪声和频率分辨率的X波段频率源设计方法,采用了谐波混频输出粗步进射频信号与HMC830LP6GE锁相环输出细步进混频环的构架,降低模块的鉴相比并固定为1:1。实现了X波段频率源输出频率范围为8 GHz~12 GHz,幅度大于13 dBm,模块频率步进为1 MHz,杂散抑制优于60 dBc的特性,且相位噪声优于-115 dBc/Hz@10 kHz。该频率源具有跳频步进小、体积小、杂散低、相位噪声低等诸多优点,能够适用于各种需要小型化、低相位噪声、低杂散X波段频率源的应用场景。

In order to realize a high resolution,low phase noise,high spurious rejection,small size and low cost X-band fre-quency source,and to solve the problems of low frequency resolution of traditional phase-locked loop frequency synthesis and low output frequency of direct digital frequency synthesis,an X-band frequency source design method based on harmonic mixing and small-step phase-locked loop to improve phase noise and frequency resolution is proposed.This method adopts the architec-ture of harmonic mixing to output coarse step RF signal and HMC830LP6GE phase-locked loop to output fine step mixing loop,reducing the module's discrimination and fixing it to 1∶1.The results show that the X-band frequency source has an output fre-quency range of 8 GHz~12 GHz,an output power greater than 13 dB,a frequency step of 1 MHz,a spurious rejection better than 60 dBc,and a phase noise better than-115 dBc/Hz@10 kHz.The frequency source has the advantages of small hopping step,small size,low spurious and low phase noise,which can be applied to various applications requiring miniaturized,low phase noise and low spurious X-band frequency source.