Hi Jean-Samuel and Andrey,
On Sun, Mar 18, 2012 at 18:25, Jean-Samuel Najnudel - BJT PARTNERS
SARL <jsn(a)bjtpartners.com> wrote:
However, I really believe the preselector should
remain on the UmTRX main
PCB.
If we want to connect the preselector as an external mezzanine board, it
would cost us 5 extra SMA connectors (RX1in, RX1out, RX2in, RX2out, clock
source), 2 RF switches before the superhet filtering (to still be able to
have switched diversity), several GPIO (serial mixer control, RF switches
control) and power supply.
This is possible but it would really cost much more than keeping the
preselector on the main PCB, especially as I believe, in practice, we will
need almsot always this preselector, even not to pass the GSM spec but just
to be able to get a reasonably narrow sampling bandwidth.
I would really suggest to keep the preselector in the main PCB and
populating or not the components (VCO/PLL, mixer and SAW IF).
Could we save on connectors if we use some RF side connector with many
pins? Nothing specific in mind, just thinking out loud.
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru