在利用可編程電路實現(xiàn)高速直接數(shù)字合成的基礎(chǔ)上，提出了一種通過實時改變直接數(shù)字合成頻率控制字，直接實現(xiàn)波形頻率調(diào)制的方法。重點對高速相位累加器、FM、掃頻、FSK等調(diào)制的實現(xiàn)方法進行了分析并基于FPJ進行，數(shù)據(jù)能夠穩(wěn)定建立，頻率合成正確。
關(guān) 鍵 詞 任意波形發(fā)生器; 直接數(shù)字合成; 相位累加器; 頻率控制字

Abstract Direct Digital Synthesis is a new kind of frequency synthesizing technology that is widely applied in arbitrary waveform generator. This paper introduces a realization of DDS, which is based on programmable device. It also presented a method of realizing frequency modulation by real-time changing frequency tuning word of high-speed phase accumulator, Frequency sweep, FM and FSK modulation are analyzed and designed. The data can be built stably and the frequency be synthesized is correct.
Key words arbitrary waveform generator; direct digital synthesis; phase accumulator; frequency tuning word