According to AD9914 datasheet,I use AWG to generate a square wave control signal and give a external clock signal at 3.5 GHz,but the DDS isn't working.
These are the control signal parameters:100Hz,duty cycle 90%,offset 1.65 VDC,3.3 Vpp
Sure.The purpose I'm using AD9914 is to generate a linear chirp signal for FMCW radar system.The chirp will sweep from 890 MHz to 905 MHz,with a frequency at 100 Hz and 90% duty cycle.
To achieve that,I use an AWG to generate a square wave control signal to control whether sweeping or not.For example,in a period of the square wave (10 ms),there will have 9 ms at high level (3.3 V) and 1ms at low level (0 V).Therefore,the chirp will sweep from 890 MHz to 905 MHz in 9ms and will cease for 1 ms,causing 90% duty cycle.
So,what I'm curious is that according to datasheet,once the square wave reached high level (3.3V),it should be high enough to trigger AD9914 to sweep,but it didn't work.
AD9914 set up
Sweeping parameters
External clock
