在对直接频率合成、锁相环频率合成和直接数字频率合成三种基本频率合成技术，以及目前常用跳频频率合成器技术方案进行简要分析和对比的基础上，提出了一种由直接数字频率合成和倍频链构成的适用于超高速跳频的频率合成器设计方案，较好地解决了在保证频率高速切换条件下达到超高速跳频频率合成器输出频谱纯度要求的技术难点，并给出了采用该方案的具体实验结果。关 键 词 频率合成器; 直接频率合成; 锁相环; 直接数字频率合成; 杂散抑制Abstract Base on the discussion of three kinds of basic technique of frequency synthesis such as direct frequency synthesis、phase-locked loop and direct digital synthesis, and several implementation technique of frequency synthesizer, a design of frequency synthesizer combining direct digital synthesis with a chain of frequency multiplier is given. This type of frequency synthesizer is especially suitable for ultra-high-speed frequency-hop system., and find a solution that the output frequency spectrum purity of frequency synthesizer is guaranteed on the condition of ultra high speed frequency hopping. Some experimental results are also presented in the end.Key words frequency synthesizer; direct frequency synthesis; phase-locked loop; direct digital synthesis; spurious suppression