Hi,
I can see that the XCVR2450 allows to set a TX gain from 0dB to 30dB.
I see in the XCVR2450 schematics that in the TX path path there is a
MAXIM2829 chip (which has a programmable TX gain register from 0 to 64
value) and then a power amplifier which amplifies 25-30dB (depending on
the
frequency band). I also see in the firmware of the UHD that the value
set in
software (from 0 to 30 dB) is not split between the MAX chip gain and a
IRM046U7 Power amplifier.
However I can see Ettus website that the XCVR2450 board in the transmit
path
has a gain of:
VGA: 0-30 dB range
BB: 0-5 dB range
Is VGA gain the gain of the power amplifier and BB gain is the gain of
the
MAXIM chip? How are these two values set from the overall gain set in
software (0 - 30 dB) ? It is not detailed in the firmware code. I need
to
understand where the 0 to 30 dB gain is psychically placed in the
XCVR2450
(MAXIM or power amplifier)
Many thanks,
Jorge