The AD9911 is a complete direct digital synthesizer （DDS）。 This device includes a high speed DAC with excellent wideband and narrowband spurious-free dynamic range （SFDR） as well as three auxiliary DDS cores without assigned digital-to-analog converters （DACs）。 These auxiliary channels are used for spur reduction， multitone generation， or test-tone modulation. The AD9911 is the first DDS to incorporate SpurKiller technology and multitone generation capability. Multitone mode enables the generation up to four concurrent carriers; frequency， phase and amplitude can be independently programmed. Multitone generation can be used for system tests， such as inter-modulation distortion and receiver blocker sensitivity. SpurKilling enables customers to improve SFDR performance by reducing the magnitude of harmonic components and/or the aliases of those harmonic components. Test-tone modulation efficiently enables sine wave modulation of amplitude on the output signal using one of the auxiliary DDS cores. The AD9911 can perform modulation of frequency， phase， or amplitude （FSK， PSK， ASK）。 Modulation is implemented by storing profiles in the register bank and applying data to the profile pins. In addition， the AD9911 supports linear sweep of frequency， phase， or amplitude for applications such as radar and instrumentation.