i am using AD9954 DDS as a frequency sweep generator from 70MHz to 110MHz ( sweep) . I
measured the output using Spectrum analyzer with the following setting.
resolution band width 100Hz
video band width 100Hz
DDS is running with 25Mhz crystal with a multiplying factor of 16. ( system clock 400MHz)
DDS frequency set to 100MHz (fixed).
I think the output spectrum is not correct. There are three frequencies with -5 dbm
level.One peak is at 100Mhz and the two other with +-250khz offset around 100Mhz.
There are also other frequencies but with low level. Can i get a pure output as
shown in the datasheet of the device?