LMX2492EVM: Continuous Sawtooth Ramp

Hi Kacem,

Your Vtune voltage looks normal, would that be a spectrum analyzer issue?

If you do not ramp, can you lock it to 9600MHz and 9700MHz?

Thank you Noel Fung for your response I lock to 9600MHz and 9700MHz, and I got the result below:

But when I switch to continious sawtooth ramp I get the same weak signal

Hi Kacem,

the measured power is very small even if it is not ramping. Could you check your spectrum analyzer configuration again?

If you use spectrum analyzer to capture the ramping, you should use max. hold. 

I retested without 20db attenuator:

But When ramping, the signal is still weak 

Hi Kacem,

I strongly believe it is a spectrum analyzer issue, probably due to improper RBW setting, your sweep time is also too long. Do you have test equipment that can measure freq vs time?

Indeed you are right I have a doubt to the sweep time, here is the technical characteristics of the spectrum analyzer: 

 I retested with another spectrum analyzer which gave me -5dbm in RFOUT for (9.6GHZ, 9.7GHZ and ramp 9.6 to9.7GHZ) while it gave -9 dbm in RFOUT/2 for the same frequencies it looks like enhanced since the power outout is stable but the doubts still exist since I have a limitation in sweep time to 10ms however the ramp duration is 100us.

Noel Fung which output power I have to reach with this EVM in RFOUT and RFOUT/2. can you send me an example of a continious sawtooth ramp with the same EVM, otherwise, an Excel table which contains the measure power of several single frequencies and ramps