Tool/software: TINA-TI or Spice Models
it's the picture of the result of my moudle by network analyzer
what is the question about my moudle,following is my circuit
I used the input Parallel resistance 50ohm and output Parallel resistance 50ohm for impedance matching；
the R2 and R3 for 330ohm and 330ohm
For measuring the frequency response of the THS3001 EVM, you would have to setup the EVM in the below configuration for 50-ohm input and output at the network analyzer. This setup should give you a matched 50-ohm input S11 and output S22 for the THS3001 EVM without a decrease in output amplitude across frequency.
Best Regards,
Rohit
Hi Rohit，
Thanks for reply.
Following is my Schematic diagram. I used the circuit to test my moudle ,the circuit gave by THS3001 datasheet. I also change Rf and Rg for 1000ohm,but the problem does not change. it always has a decrease in output amplitude across frequency.
And I always use this circuit for my Amplifiers to match 50ohm ，but sometimes my moudle have the same problem.and the same graph show on the network analyzer,when i test it.
Hi Darren,
It is common to notice the decrease in output amplitude across frequency for an amplifier, because of the BW roll-off across frequency. If you notice the S21 marker at 77.68MHz in your network analyzer plot, it shows to be around 4.4dB which is normal for this part. I would recommend you to plot your network analyzer graphs with log scale in x-axis so as to better compare with measurement already available in the THS3001 EVM.
Best Regards,
Rohit
