Other Parts Discussed in Thread: LMX2492,
Hi fellow EEs,
I have been using the LMX2492 in its ramping (FMCW) mode, and programming it with TICS Pro(which proved to be an effective approach with relatively few problems apart from occasional crashes).
I used the ramping function with the following settings, and measured everything on the RFout output of my Rev.C LMX2492EVM :
- 9600 MHz --> 9800 MHz frequency sweep range ;
- 100 µs ramp duration.
The ramp loops on itself (previous settings are for ramp 0, thus RAMP0_NEXT is set to 0).
The end frequency of the generated pattern being different from the beginning frequency, RAMP0_RST is activated.
I successfully generate a ramp, however when measuring the power levels at a given frequency inside the sweep range (zero span view on SA), I also measured a spur on ramp reset.
When using a more performant SA with Pulse measurement features, I was able to get a time domain view of the ramp itself (not just its spectrum) :
As you can tell, on ramp reset, there is a significant parasitic pulse (see top left/bottom left-most).
However, this event and behavior between ramps is not seen in the LMX2492EVM's User's Guide (3.2.2, Fig.10).
Is there way to reduce or completely eliminate it? I have tried using a negative ramp segment to avoid using the RST function, to no avail.
Thanks in advance for your insight,
Regards,
Nicolas