Someone on the FMCOMMS3 product page:
Someone made the comment:
Power o/p is not as claimed in data sheet. and i tried all the way to get o/p power more than -15 dBm on 400 Mhz, but not able to achieve.
The output power of the chip does not include the loss of the transformer on the FMCOMMS3 board. The -15dBm number is expected, and is shown in the performance metrics we have:
This is due to the mini circuits transformer. (1-2 dB of insertion loss) and the 330nH inductors which are used to help power the Tx side.
by changing those inductors - power at 400MHz can go up, but then it will drop worse than it does at 6GHz.
I'm sure that Tomas can comment more as well.